Merge pull request 'release: offline mode + local pass-and-play (hotseat) — proposed v1.12.0' (#212) from development into master

The 2-4 hotseat players now start in a random seating order (so who goes
first, and the turn order, is random) — matching the online games. The
engine starts at seat 0, so shuffling the seats at creation picks the
starter; the shuffle is seed-driven (a distinct derivation from the tile
bag), so replay reproduces it. Scoped to hotseat — vs_ai stays human-first.
- lib/roster.ts: shuffleSeeded (unit-tested); NewGame shuffles buildSeats
  with the game seed before create.
- e2e: pin a seed that keeps the roster order so the lock assertions stay
  deterministic.

.gitea/workflows/ci.yaml

@@ -214,9 +214,21 @@ jobs:
         run: pnpm exec playwright install chromium webkit
         timeout-minutes: 5
 
+      # The offline e2e plays a real local vs_ai game, so it needs the per-variant dawgs; fetch the
+      # release the same way the Go jobs do and point the mock preview's copy step (scripts/
+      # e2e-dict.mjs, via E2E_DICT_DIR below) at it.
+      - name: Fetch dictionary DAWGs
+        run: |
+          mkdir -p "${GITHUB_WORKSPACE}/dawg"
+          curl -fsSL -o /tmp/dawg.tar.gz "https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/${DICT_VERSION}/scrabble-dawg-${DICT_VERSION}.tar.gz"
+          tar xzf /tmp/dawg.tar.gz -C "${GITHUB_WORKSPACE}/dawg"
+          ls -la "${GITHUB_WORKSPACE}/dawg"
+
       - name: E2E smoke (mock)
         run: pnpm run test:e2e
         timeout-minutes: 5
+        env:
+          E2E_DICT_DIR: ${{ github.workspace }}/dawg
 
   # conformance proves the client's local move preview (the ported dawg reader +
   # validator, ui/src/lib/dict) byte-for-byte against the authoritative Go engine:
@@ -252,6 +264,7 @@ jobs:
         run: |
           go run ./backend/cmd/dictgen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out /tmp/dictgold
           go run ./backend/cmd/validategen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out /tmp/validgold
+          go run ./backend/cmd/movegen -dawg-dir "${GITHUB_WORKSPACE}/dawg" -out "${GITHUB_WORKSPACE}/movegold"
 
       - name: Set up Node
         uses: actions/setup-node@v4
@@ -271,6 +284,7 @@ jobs:
           DICT_DAWG_DIR: ${{ github.workspace }}/dawg
           DICT_GOLD_DIR: /tmp/dictgold
           DICT_VALID_DIR: /tmp/validgold
+          DICT_MOVEGEN_DIR: ${{ github.workspace }}/movegold
         run: pnpm exec vitest run src/lib/dict/
 
   # gate is the single branch-protection required check. It always runs and passes

backend/cmd/backend/main.go

@@ -12,7 +12,6 @@ import (
 	"fmt"
 	"log"
 	"os/signal"
-	"strings"
 	"syscall"
 	"time"
 
@@ -216,11 +215,9 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	// Operator alert emails on new feedback / word complaints, coalesced into one digest
 	// per interval. Inert unless a distinct admin sender and recipient are configured.
 	if cfg.SMTP.AdminFrom != "" && cfg.SMTP.AdminTo != "" {
-		consoleURL := ""
+		// The alert digest carries no admin-console link on purpose — an admin URL must not
-		if cfg.PublicBaseURL != "" {
+		// travel in an email (a mail provider could cache or index it); see adminalert.New.
-			consoleURL = strings.TrimRight(cfg.PublicBaseURL, "/") + "/_gm"
+		alerts := adminalert.New(mailer, feedbackSvc, games, cfg.SMTP.AdminFrom, cfg.SMTP.AdminTo, logger)
-		}
-		alerts := adminalert.New(mailer, feedbackSvc, games, cfg.SMTP.AdminFrom, cfg.SMTP.AdminTo, consoleURL, logger)
 		go alerts.Run(ctx, adminAlertInterval)
 		logger.Info("admin alert worker started", zap.Duration("interval", adminAlertInterval))
 	}

backend/cmd/movegen/main.go

@@ -0,0 +1,417 @@
+// Command movegen emits golden conformance fixtures for the client-side move
+// generator port (ui/src/lib/dict). It is a dev tool, run by hand; its output is
+// committed so the TypeScript parity tests run without a Go toolchain.
+//
+// For each small sample dictionary (English and Russian — the latter reaches
+// alphabet index 32, exercising the 33-letter cross-set boundary) it writes:
+//
+//   - sample_<tag>.dawg           the serialized dictionary (the reader/cursor fixture)
+//   - sample_<tag>.words.json     the stored words + their alphabet indexes
+//   - sample_<tag>.gen.json       ranked move-generation results from the real solver,
+//     for a handful of positions, plus the ruleset the TS
+//     side rebuilds to score identically
+//
+// Positions are built with only the solver's public API: an empty board, and
+// two-ply positions reached by applying the solver's own top move (so no internal
+// encoding is needed). Regenerate with:
+//
+//	go run ./backend/cmd/movegen -out ui/src/lib/dict/testdata
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.iliadenisov.ru/developer/scrabble-solver/board"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rack"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+	"gitea.iliadenisov.ru/developer/scrabble-solver/scrabble"
+	dawg "github.com/iliadenisov/dafsa"
+)
+
+// sampleWordsEN is the English sample dictionary, in strictly increasing
+// alphabet-index order (the builder requires it). Shared prefixes (car/care/cars),
+// shared suffixes (cats/dogs), internal-final nodes (do, an) and a one-letter word.
+var sampleWordsEN = []string{
+	"a", "an", "and", "ant",
+	"car", "care", "cared", "cares", "cars", "cat", "cats",
+	"do", "doe", "does", "dog", "dogs", "done", "dot",
+}
+
+// sampleWordsRU is the Russian sample dictionary, in strictly increasing index
+// order. It deliberately includes words starting with я (index 32) so the ported
+// cross-set handles alphabet indexes past JS's 31-bit shift boundary.
+var sampleWordsRU = []string{"ад", "ар", "оса", "я", "яд", "яр"}
+
+// sampleFixture is the JSON committed with the .dawg so the TypeScript cursor test
+// knows the exact word set (as alphabet indexes) to expect from enumeration.
+type sampleFixture struct {
+	Alphabet string   `json:"alphabet"`
+	NumAdded int      `json:"numAdded"`
+	Words    []string `json:"words"`
+	Indexes  [][]int  `json:"indexes"`
+}
+
+// genFixture is the move-generation golden set for one sample dictionary.
+type genFixture struct {
+	Ruleset genRuleset `json:"ruleset"`
+	Cases   []genCase  `json:"cases"`
+}
+
+// genRuleset is the scoring data the TS side rebuilds so evaluate() matches the Go
+// solver: letter values, premium multipliers per square, the centre, rack size and bonus.
+type genRuleset struct {
+	Size       int     `json:"size"`
+	Cols       int     `json:"cols"`
+	Center     int     `json:"center"`
+	RackSize   int     `json:"rackSize"`
+	Bingo      int     `json:"bingo"`
+	Values     []int   `json:"values"`
+	LetterMult [][]int `json:"letterMult"`
+	WordMult   [][]int `json:"wordMult"`
+}
+
+// genTile is one placed tile (a board tile or a move placement).
+type genTile struct {
+	Row    int  `json:"row"`
+	Col    int  `json:"col"`
+	Letter int  `json:"letter"`
+	Blank  bool `json:"blank"`
+}
+
+// genRack is a rack as a multiset of letter indexes plus a blank count.
+type genRack struct {
+	Letters []int `json:"letters"`
+	Blanks  int   `json:"blanks"`
+}
+
+// genMove is one ranked generated play: its orientation, placed tiles and total score.
+type genMove struct {
+	Dir   int       `json:"dir"`
+	Tiles []genTile `json:"tiles"`
+	Score int       `json:"score"`
+}
+
+// genCase is one generation position: the tiles already on the board (empty when
+// none), the rack, the mode/rule and the ranked moves the solver returns.
+type genCase struct {
+	Name             string    `json:"name"`
+	Placed           []genTile `json:"placed"`
+	Rack             genRack   `json:"rack"`
+	Mode             int       `json:"mode"`
+	IgnoreCrossWords bool      `json:"ignoreCrossWords"`
+	Moves            []genMove `json:"moves"`
+}
+
+func main() {
+	out := flag.String("out", "ui/src/lib/dict/testdata", "output directory for fixtures")
+	dawgDir := flag.String("dawg-dir", "", "when set, emit real-dictionary move-gen golden from the .dawg files in this dir (conformance mode) instead of the committed samples")
+	flag.Parse()
+
+	if err := os.MkdirAll(*out, 0o755); err != nil {
+		log.Fatalf("movegen: mkdir %s: %v", *out, err)
+	}
+
+	if *dawgDir != "" {
+		buildReal(*dawgDir, *out)
+		return
+	}
+
+	emitRulesets()
+
+	buildSample(*out, "en", rules.English(), sampleWordsEN, []genCase{
+		emptyCase("empty-cared", englishRack("caredts", 0), scrabble.Both, false),
+		emptyCase("empty-dogs", englishRack("dogsent", 0), scrabble.Both, false),
+		emptyCase("empty-blank", englishRack("caret", 1), scrabble.Both, false),
+		emptyCase("empty-single-word", englishRack("caredts", 0), scrabble.Both, true),
+	})
+
+	buildSample(*out, "ru", rules.RussianScrabble(), sampleWordsRU, []genCase{
+		emptyCase("empty-yad", russianRack("ядрасо", 0), scrabble.Both, false),
+	})
+}
+
+// buildSample writes the dawg, the word fixture and the generation golden set for
+// one sample dictionary. Two-ply cases are appended: the solver's own top move from
+// the first non-empty result is applied, then generation runs again on the new rack.
+func buildSample(out, tag string, rs *rules.Ruleset, words []string, cases []genCase) {
+	idx := rs.Alphabet
+	b := dawg.New(idx)
+	indexes := make([][]int, 0, len(words))
+	for _, w := range words {
+		if err := b.Add(w); err != nil {
+			log.Fatalf("movegen[%s]: add %q: %v", tag, w, err)
+		}
+		enc, err := idx.Encode(w)
+		if err != nil {
+			log.Fatalf("movegen[%s]: encode %q: %v", tag, w, err)
+		}
+		ints := make([]int, len(enc))
+		for i, x := range enc {
+			ints[i] = int(x)
+		}
+		indexes = append(indexes, ints)
+	}
+	finder := b.Finish()
+
+	writeJSON(filepath.Join(out, "sample_"+tag+".words.json"), sampleFixture{
+		Alphabet: tag, NumAdded: finder.NumAdded(), Words: words, Indexes: indexes,
+	})
+	dawgPath := filepath.Join(out, "sample_"+tag+".dawg")
+	if _, err := finder.Save(dawgPath); err != nil {
+		log.Fatalf("movegen[%s]: save %s: %v", tag, dawgPath, err)
+	}
+
+	s := scrabble.NewSolver(rs, finder)
+	for i := range cases {
+		runCase(s, rs, &cases[i], nil)
+	}
+	// A two-ply position from the first standard case that produced a move.
+	if two := twoPly(s, rs, cases); two != nil {
+		cases = append(cases, *two)
+	}
+
+	writeJSON(filepath.Join(out, "sample_"+tag+".gen.json"), genFixture{
+		Ruleset: rulesetOf(rs), Cases: cases,
+	})
+	log.Printf("movegen[%s]: %d words, %d cases", tag, finder.NumAdded(), len(cases))
+}
+
+// realVariant maps a shipped dictionary file to the ruleset that scores it and the racks
+// the conformance positions use. smallRack/blankRack keep the first-move (empty board)
+// lists bounded on a dense dictionary; fullRack drives a deep 7-tile mid-game position,
+// kept small by the anchors around the already-placed word.
+type realVariant struct {
+	file, variant, smallRack, blankRack, fullRack string
+	rs                                            *rules.Ruleset
+}
+
+// buildReal emits move-generation golden from the real shipped dictionaries in dawgDir —
+// the full alphabets and deep graphs the tiny samples cannot reach — one
+// <variant>.movegen.json per variant. Like the dictgen/validategen vectors it is
+// regenerated in CI and never committed, so it pins no dictionary version into the repo.
+func buildReal(dawgDir, out string) {
+	reals := []realVariant{
+		{"en_sowpods", "scrabble_en", "aine", "ain", "aeinrst", rules.English()},
+		{"ru_scrabble", "scrabble_ru", "аеин", "аен", "аеиноср", rules.RussianScrabble()},
+		{"ru_erudit", "erudit_ru", "аеин", "аен", "аеиноср", rules.Erudit()},
+	}
+	for _, v := range reals {
+		data, err := os.ReadFile(filepath.Join(dawgDir, v.file+".dawg"))
+		if err != nil {
+			log.Fatalf("movegen[%s]: read dawg: %v", v.variant, err)
+		}
+		finder, err := dawg.Read(bytes.NewReader(data), 0)
+		if err != nil {
+			log.Fatalf("movegen[%s]: parse dawg: %v", v.variant, err)
+		}
+		s := scrabble.NewSolver(v.rs, finder)
+
+		cases := []genCase{
+			emptyCase("first-move", encRack(v.rs, v.smallRack, 0), scrabble.Both, false),
+			emptyCase("first-move-blank", encRack(v.rs, v.blankRack, 1), scrabble.Both, false),
+		}
+		for i := range cases {
+			runCase(s, v.rs, &cases[i], nil)
+		}
+		// A deep 7-tile mid-game: place the top first move, then generate again. The
+		// anchors around the placed word bound the list while still exercising a full rack,
+		// deep left/right extension and wide cross-sets over the real graph.
+		full := encRack(v.rs, v.fullRack, 0)
+		b := board.New(v.rs.Rows, v.rs.Cols)
+		if m1 := s.GenerateMovesOpts(b, toRack(v.rs.Size(), full), scrabble.Both, scrabble.PlayOptions{}); len(m1) > 0 {
+			mid := genCase{Name: "mid-game", Rack: full, Mode: int(scrabble.Both)}
+			runCase(s, v.rs, &mid, tilesOf(m1[0].Tiles))
+			cases = append(cases, mid)
+		}
+
+		writeJSON(filepath.Join(out, v.variant+".movegen.json"), genFixture{Ruleset: rulesetOf(v.rs), Cases: cases})
+		total := 0
+		for _, c := range cases {
+			total += len(c.Moves)
+		}
+		_ = finder.Close()
+		log.Printf("movegen[%s]: %d cases, %d golden moves", v.variant, len(cases), total)
+	}
+}
+
+// encRack encodes a rack given as the variant's letters (plus a blank count) into the
+// index-based genRack the fixtures carry.
+func encRack(rs *rules.Ruleset, letters string, blanks int) genRack {
+	enc, err := rs.Alphabet.Encode(letters)
+	if err != nil {
+		log.Fatalf("movegen: encode rack %q: %v", letters, err)
+	}
+	idx := make([]int, len(enc))
+	for i, b := range enc {
+		idx[i] = int(b)
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// runCase fills a case's Moves by generating on a board holding the given placed
+// tiles (nil = empty board).
+func runCase(s *scrabble.Solver, rs *rules.Ruleset, c *genCase, placed []genTile) {
+	bd := board.New(rs.Rows, rs.Cols)
+	for _, t := range placed {
+		bd.Set(t.Row, t.Col, cellByte(t.Letter, t.Blank))
+	}
+	c.Placed = placed
+	rk := toRack(rs.Size(), c.Rack)
+	moves := s.GenerateMovesOpts(bd, rk, scrabble.Mode(c.Mode), scrabble.PlayOptions{IgnoreCrossWords: c.IgnoreCrossWords})
+	c.Moves = movesOf(moves)
+}
+
+// twoPly reaches a mid-game position by applying the top move of the first standard
+// case that generated one, then generates again with a fresh rack of the same tiles.
+func twoPly(s *scrabble.Solver, rs *rules.Ruleset, cases []genCase) *genCase {
+	for _, c := range cases {
+		if c.IgnoreCrossWords || len(c.Moves) == 0 {
+			continue
+		}
+		placed := c.Moves[0].Tiles
+		next := genCase{Name: "two-ply", Rack: c.Rack, Mode: int(scrabble.Both)}
+		runCase(s, rs, &next, placed)
+		return &next
+	}
+	return nil
+}
+
+// cellByte encodes a board cell the way internal/encoding.Cell does (bits 0-5 hold
+// letter+1, bit 7 marks a blank). Duplicated here because that package is internal
+// to the solver module and cannot be imported.
+func cellByte(letter int, blank bool) byte {
+	v := byte(letter+1) & 0x3f
+	if blank {
+		v |= 0x80
+	}
+	return v
+}
+
+func toRack(size int, r genRack) rack.Rack {
+	rk := rack.New(size)
+	for _, l := range r.Letters {
+		rk.Add(byte(l))
+	}
+	for i := 0; i < r.Blanks; i++ {
+		rk.AddBlank()
+	}
+	return rk
+}
+
+func rulesetOf(rs *rules.Ruleset) genRuleset {
+	lm := make([][]int, rs.Rows)
+	wm := make([][]int, rs.Rows)
+	for r := 0; r < rs.Rows; r++ {
+		lm[r] = make([]int, rs.Cols)
+		wm[r] = make([]int, rs.Cols)
+		for c := 0; c < rs.Cols; c++ {
+			p := rs.Premium(r, c)
+			lm[r][c] = p.LetterMult()
+			wm[r][c] = p.WordMult()
+		}
+	}
+	return genRuleset{
+		Size: rs.Size(), Cols: rs.Cols, Center: rs.Center, RackSize: rs.RackSize,
+		Bingo: rs.Bingo, Values: rs.Values, LetterMult: lm, WordMult: wm,
+	}
+}
+
+func movesOf(ms []scrabble.Move) []genMove {
+	out := make([]genMove, len(ms))
+	for i, m := range ms {
+		out[i] = genMove{Dir: int(m.Dir), Tiles: tilesOf(m.Tiles), Score: m.Score}
+	}
+	return out
+}
+
+func tilesOf(ps []scrabble.Placement) []genTile {
+	out := make([]genTile, len(ps))
+	for i, p := range ps {
+		out[i] = genTile{Row: p.Row, Col: p.Col, Letter: int(p.Letter), Blank: p.Blank}
+	}
+	return out
+}
+
+// emptyCase builds an empty-board case (Moves filled later by runCase).
+func emptyCase(name string, r genRack, mode scrabble.Mode, ignoreCross bool) genCase {
+	return genCase{Name: name, Rack: r, Mode: int(mode), IgnoreCrossWords: ignoreCross}
+}
+
+// englishRack builds a rack from lowercase a-z letters (index = letter-'a').
+func englishRack(letters string, blanks int) genRack {
+	idx := make([]int, 0, len(letters))
+	for _, ch := range letters {
+		idx = append(idx, int(ch-'a'))
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// russianRack builds a rack from the Russian sample letters used above.
+func russianRack(letters string, blanks int) genRack {
+	m := map[rune]int{'а': 0, 'д': 4, 'о': 15, 'р': 17, 'с': 18, 'я': 32}
+	idx := make([]int, 0, len([]rune(letters)))
+	for _, ch := range letters {
+		i, ok := m[ch]
+		if !ok {
+			log.Fatalf("movegen: russianRack: no index for %q", string(ch))
+		}
+		idx = append(idx, i)
+	}
+	return genRack{Letters: idx, Blanks: blanks}
+}
+
+// emitRulesets writes the per-variant static ruleset data (tile values, bag counts, blanks,
+// bingo, rack size) the offline engine mirrors in ui/src/lib/localgame/ruleset.ts, so a TS
+// parity test can pin that hand-copied table to the Go rulesets (scrabble-solver/rules).
+func emitRulesets() {
+	type rsFix struct {
+		Size     int      `json:"size"`
+		RackSize int      `json:"rackSize"`
+		Bingo    int      `json:"bingo"`
+		Blanks   int      `json:"blanks"`
+		Values   []int    `json:"values"`
+		Counts   []int    `json:"counts"`
+		Letters  []string `json:"letters"`
+	}
+	out := map[string]rsFix{}
+	for _, v := range []struct {
+		name string
+		rs   *rules.Ruleset
+	}{
+		{"scrabble_en", rules.English()},
+		{"scrabble_ru", rules.RussianScrabble()},
+		{"erudit_ru", rules.Erudit()},
+	} {
+		letters := make([]string, v.rs.Size())
+		for i := range letters {
+			ch, err := v.rs.Alphabet.Character(byte(i))
+			if err != nil {
+				log.Fatalf("movegen: %s letter %d: %v", v.name, i, err)
+			}
+			letters[i] = strings.ToUpper(ch)
+		}
+		out[v.name] = rsFix{Size: v.rs.Size(), RackSize: v.rs.RackSize, Bingo: v.rs.Bingo, Blanks: v.rs.Blanks, Values: v.rs.Values, Counts: v.rs.Counts, Letters: letters}
+	}
+	dir := filepath.Join("ui", "src", "lib", "localgame", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		log.Fatalf("movegen: mkdir %s: %v", dir, err)
+	}
+	writeJSON(filepath.Join(dir, "rulesets.json"), out)
+	log.Printf("movegen: wrote %s (3 variants)", filepath.Join(dir, "rulesets.json"))
+}
+
+func writeJSON(path string, v any) {
+	data, err := json.MarshalIndent(v, "", "  ")
+	if err != nil {
+		log.Fatalf("movegen: marshal %s: %v", path, err)
+	}
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		log.Fatalf("movegen: write %s: %v", path, err)
+	}
+}

backend/internal/account/email.go

@@ -105,9 +105,10 @@ func (s *EmailService) allowSend(email string) bool {
 
 // issueCode generates a fresh confirm-code and one-tap deeplink token for (accountID,
 // email), replaces any prior pending confirmation, and mails the branded code in
-// locale; purpose selects the email wording and what verifying does. Only the SHA-256
+// locale; purpose selects the email wording and what verifying does. omitLink drops the
-// hashes of the code and token are stored.
+// one-tap deeplink from the email (account deletion, or a login requested from an installed
-func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email, purpose, locale string) error {
+// PWA). Only the SHA-256 hashes of the code and token are stored.
+func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email, purpose, locale string, omitLink bool) error {
 	code, codeHash, err := generateCode()
 	if err != nil {
 		return err
@@ -119,11 +120,12 @@ func (s *EmailService) issueCode(ctx context.Context, accountID uuid.UUID, email
 	if err := s.store.replacePendingConfirmation(ctx, accountID, email, codeHash, tokenHash, purpose, s.now().Add(emailCodeTTL)); err != nil {
 		return err
 	}
-	// Account deletion is never a one-tap link (a prefetch or a stray click must not delete
+	// Omit the one-tap deeplink when asked: for a login from an installed PWA (the link would
-	// an account): the delete code is entered in the app only, so the email omits the
+	// open in a separate browser whose minted session cannot reach the PWA), or for account
-	// deeplink and ConfirmByToken refuses a delete token.
+	// deletion (a prefetch or stray click must not delete an account — the delete code is entered
+	// in the app only, and ConfirmByToken refuses a delete token).
 	deeplink := s.confirmURL(token, locale)
-	if purpose == purposeDelete {
+	if purpose == purposeDelete || omitLink {
 		deeplink = ""
 	}
 	msg, err := renderConfirmationEmail(purpose, code, deeplink, s.baseURL, locale)
@@ -175,7 +177,7 @@ func (s *EmailService) RequestCode(ctx context.Context, accountID uuid.UUID, ema
 		}
 		return ErrEmailTaken
 	}
-	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID))
+	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID), false)
 }
 
 // ConfirmCode verifies code for accountID and email. On success it attaches a
@@ -221,8 +223,11 @@ func (s *EmailService) ConfirmCode(ctx context.Context, accountID uuid.UUID, ema
 // the ordinary returning-user login. The code is mailed to the address, so only its
 // real owner can complete the login. On first contact browserTZ (the client's
 // detected "±HH:MM" UTC offset) seeds the new account's time zone and language its UI
-// language. It returns the target account id for the subsequent LoginWithCode.
+// language. When pwa is set (the request came from an installed PWA) the login email omits the
-func (s *EmailService) RequestLoginCode(ctx context.Context, email, browserTZ, language string) (uuid.UUID, error) {
+// one-tap confirm link — it would open in a separate browser, out of the PWA's reach — so the
+// code is entered in the same window. It returns the target account id for the subsequent
+// LoginWithCode.
+func (s *EmailService) RequestLoginCode(ctx context.Context, email, browserTZ, language string, pwa bool) (uuid.UUID, error) {
 	addr, err := normalizeEmail(email)
 	if err != nil {
 		return uuid.UUID{}, err
@@ -234,7 +239,7 @@ func (s *EmailService) RequestLoginCode(ctx context.Context, email, browserTZ, l
 	if err != nil {
 		return uuid.UUID{}, err
 	}
-	if err := s.issueCode(ctx, acc.ID, addr, purposeLogin, language); err != nil {
+	if err := s.issueCode(ctx, acc.ID, addr, purposeLogin, language, pwa); err != nil {
 		return uuid.UUID{}, err
 	}
 	return acc.ID, nil

backend/internal/account/link.go

@@ -92,7 +92,7 @@ func (s *EmailService) RequestLinkCode(ctx context.Context, accountID uuid.UUID,
 	if !s.allowSend(addr) {
 		return ErrTooManyRequests
 	}
-	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID))
+	return s.issueCode(ctx, accountID, addr, purposeLink, s.accountLocale(ctx, accountID), false)
 }
 
 // ConfirmLink verifies code for (accountID, email) and reports the address's
@@ -140,7 +140,7 @@ func (s *EmailService) RequestChangeCode(ctx context.Context, accountID uuid.UUI
 	if !s.allowSend(addr) {
 		return ErrTooManyRequests
 	}
-	return s.issueCode(ctx, accountID, addr, purposeChange, s.accountLocale(ctx, accountID))
+	return s.issueCode(ctx, accountID, addr, purposeChange, s.accountLocale(ctx, accountID), false)
 }
 
 // ConfirmChange verifies code for (accountID, newEmail) and atomically replaces the
@@ -199,7 +199,7 @@ func (s *EmailService) RequestDeleteCode(ctx context.Context, accountID uuid.UUI
 	if !s.allowSend(addr) {
 		return ErrTooManyRequests
 	}
-	return s.issueCode(ctx, accountID, addr, purposeDelete, s.accountLocale(ctx, accountID))
+	return s.issueCode(ctx, accountID, addr, purposeDelete, s.accountLocale(ctx, accountID), false)
 }
 
 // VerifyDeleteCode verifies the account-deletion code against the account's own email and

backend/internal/adminalert/notify.go

@@ -33,21 +33,21 @@ type Notifier struct {
 	complaints ComplaintCounter
 	from       string
 	to         string
-	consoleURL string
 	clock      func() time.Time
 	log        *zap.Logger
 	last       time.Time
 }
 
-// New constructs a Notifier. from and to are the alert sender and recipient(s); consoleURL,
+// New constructs a Notifier. from and to are the alert sender and recipient(s); log may be
-// when non-empty, is the admin-console link included in the email. log may be nil. The
+// nil. The watermark starts at "now", so only items arriving after start-up are reported. The
-// watermark starts at "now", so only items arriving after start-up are reported.
+// digest deliberately carries no admin-console link — an admin URL must never travel in an
-func New(mailer account.Mailer, fb FeedbackCounter, cp ComplaintCounter, from, to, consoleURL string, log *zap.Logger) *Notifier {
+// email, where a mail provider could cache or index it.
+func New(mailer account.Mailer, fb FeedbackCounter, cp ComplaintCounter, from, to string, log *zap.Logger) *Notifier {
 	if log == nil {
 		log = zap.NewNop()
 	}
 	return &Notifier{
-		mailer: mailer, feedback: fb, complaints: cp, from: from, to: to, consoleURL: consoleURL,
+		mailer: mailer, feedback: fb, complaints: cp, from: from, to: to,
 		clock: func() time.Time { return time.Now().UTC() }, log: log, last: time.Now().UTC(),
 	}
 }
@@ -103,10 +103,9 @@ func (n *Notifier) digest(fb, cp int) account.Message {
 		parts = append(parts, fmt.Sprintf("%d new word complaint(s)", cp))
 	}
 	summary := strings.Join(parts, ", ")
+	// No admin-console link in the body: an admin URL must never travel in an email (a mail
+	// provider could cache or index it). The operator opens the console directly.
 	text := summary + "."
-	if n.consoleURL != "" {
-		text += "\n\nOpen the admin console: " + n.consoleURL
-	}
 	return account.Message{
 		From:    n.from,
 		To:      n.to,

backend/internal/adminalert/notify_test.go

@@ -28,7 +28,7 @@ func (m *recordingMailer) Send(_ context.Context, msg account.Message) error {
 
 func TestNotifierSkipsWhenNothingNew(t *testing.T) {
 	mailer := &recordingMailer{}
-	n := New(mailer, fbCounter{0}, cpCounter{0}, "alerts@erudit-game.ru", "op@x.ru", "", nil)
+	n := New(mailer, fbCounter{0}, cpCounter{0}, "alerts@erudit-game.ru", "op@x.ru", nil)
 	n.tick(context.Background())
 	if len(mailer.sent) != 0 {
 		t.Fatalf("sent %d emails, want 0 when nothing is new", len(mailer.sent))
@@ -37,7 +37,7 @@ func TestNotifierSkipsWhenNothingNew(t *testing.T) {
 
 func TestNotifierDigestsNewItems(t *testing.T) {
 	mailer := &recordingMailer{}
-	n := New(mailer, fbCounter{2}, cpCounter{1}, "alerts@erudit-game.ru", "op@x.ru, two@x.ru", "https://erudit-game.ru/_gm", nil)
+	n := New(mailer, fbCounter{2}, cpCounter{1}, "alerts@erudit-game.ru", "op@x.ru, two@x.ru", nil)
 	n.tick(context.Background())
 	if len(mailer.sent) != 1 {
 		t.Fatalf("sent %d emails, want 1 digest", len(mailer.sent))
@@ -49,7 +49,9 @@ func TestNotifierDigestsNewItems(t *testing.T) {
 	if !strings.Contains(msg.Subject, "2 new feedback") || !strings.Contains(msg.Subject, "1 new word complaint") {
 		t.Errorf("digest subject = %q, want the feedback + complaint counts", msg.Subject)
 	}
-	if !strings.Contains(msg.Text, "/_gm") {
+	// The digest must never carry an admin-console link — an admin URL in an email is a leak
-		t.Errorf("digest body = %q, want the console link", msg.Text)
+	// (mail providers cache/index it).
+	if strings.Contains(msg.Text, "/_gm") || strings.Contains(strings.ToLower(msg.Text), "admin console") {
+		t.Errorf("digest body = %q, must not carry an admin-console link", msg.Text)
 	}
 }

backend/internal/adminconsole/assets/console.css

@@ -193,3 +193,24 @@ code { background: var(--bg); padding: 0.05rem 0.3rem; border-radius: 4px; }
 .replay-log { margin: 0.4rem 0 0; padding-left: 1.4rem; max-height: 14rem; overflow: auto; font-size: 0.85rem; }
 .replay-log li { color: var(--ink-dim); padding: 0.1rem 0; }
 .replay-log li.cur { color: var(--ink); font-weight: 600; }
+
+/* Banner colour override editor + live preview (banner_detail). The override
+   fieldsets group the enable toggle with the native colour swatches; the preview
+   renders a sample strip on both themes from those inputs (see the inline script). */
+.ovr { border: 1px solid var(--line); border-radius: 6px; padding: 0.3rem 0.8rem 0.7rem; margin: 0.2rem 0; }
+.ovr legend { padding: 0 0.3rem; font-size: 0.85rem; color: var(--ink); }
+.ovr legend label { flex-direction: row; align-items: center; gap: 0.4rem; color: var(--ink); }
+.ovr .note { margin: 0.2rem 0 0.4rem; }
+.ovr .swatches { display: flex; flex-wrap: wrap; gap: 1rem; }
+.ovr .swatches label { flex-direction: column; gap: 0.25rem; align-items: flex-start; }
+.ovr input[type=color] { width: 3rem; height: 1.8rem; padding: 0; border: 1px solid var(--line); border-radius: 4px; background: var(--bg); cursor: pointer; }
+.ovr input[type=color]:disabled { opacity: 0.4; cursor: default; }
+.ovr .hex { font-size: 0.72rem; color: var(--ink-dim); font-variant-numeric: tabular-nums; }
+.banner-preview { display: flex; flex-wrap: wrap; gap: 0.8rem; margin: 0.7rem 0 0.2rem; }
+.banner-preview .bp { flex: 1 1 18rem; }
+.banner-preview .bp-label { display: block; font-size: 0.75rem; color: var(--ink-dim); margin-bottom: 0.25rem; }
+.ad-frame { padding: 0.7rem; border-radius: 6px; border: 1px solid var(--line); }
+.ad-frame.light { background: #f4f6f9; }
+.ad-frame.dark { background: #0f1420; }
+.ad-sample { padding: 0.35rem 0.7rem; font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+.ad-sample .ad-link { text-decoration: underline; }

backend/internal/adminconsole/templates/pages/banner_detail.gohtml

@@ -11,10 +11,72 @@
 <label>Starts (UTC) <input type="datetime-local" name="starts_at" value="{{.StartsAt}}"></label>
 <label>Ends (UTC) <input type="datetime-local" name="ends_at" value="{{.EndsAt}}"></label>
 <label><input type="checkbox" name="enabled"{{if .Enabled}} checked{{end}}> Enabled</label>
+<fieldset class="ovr">
+<legend><label><input type="checkbox" name="urgent"{{if .Urgent}} checked{{end}}> Urgent</label></legend>
+<p class="note">Shows to <em>everyone</em>, always — bypassing paid accounts, hint wallets and the no-banner role. While any urgent campaign is live it is the only thing the strip shows (other campaigns and the default are suppressed). For system alerts.</p>
+</fieldset>
+<fieldset class="ovr" data-ovr-group>
+<legend><label><input type="checkbox" name="override_all_on" data-ovr="all"{{if .OverrideAllOn}} checked{{end}}> Colour override — all themes</label></legend>
+<div class="swatches">
+<label>Background <input type="color" name="override_bg" value="{{.AllBg}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Text <input type="color" name="override_fg" value="{{.AllFg}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Link <input type="color" name="override_link" value="{{.AllLink}}" data-ovr-color{{if not .OverrideAllOn}} disabled{{end}}><span class="hex"></span></label>
+</div>
+</fieldset>
+<fieldset class="ovr" data-ovr-group>
+<legend><label><input type="checkbox" name="override_dark_on" data-ovr="dark"{{if .OverrideDarkOn}} checked{{end}}> Colour override — dark theme only</label></legend>
+<div class="swatches">
+<label>Background <input type="color" name="override_bg_dark" value="{{.DarkBg}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Text <input type="color" name="override_fg_dark" value="{{.DarkFg}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+<label>Link <input type="color" name="override_link_dark" value="{{.DarkLink}}" data-ovr-color{{if not .OverrideDarkOn}} disabled{{end}}><span class="hex"></span></label>
+</div>
+</fieldset>
 {{end}}
 <div><button type="submit">Save</button></div>
 </form>
 {{if not .IsDefault}}
+<div class="banner-preview">
+<div class="bp"><span class="bp-label">Light theme</span><div class="ad-frame light"><div class="ad-sample" id="prev-light"><span>Sample banner text — <span class="ad-link">a link</span></span></div></div></div>
+<div class="bp"><span class="bp-label">Dark theme</span><div class="ad-frame dark"><div class="ad-sample" id="prev-dark"><span>Sample banner text — <span class="ad-link">a link</span></span></div></div></div>
+</div>
+<p class="note">Live preview of the strip on both themes. An empty override falls back to the neutral theme colours; the top/bottom border is derived from the background.</p>
+<script>
+(function(){
+  // Neutral fallbacks — mirror ui/src/app.css (--ad-bg / --text-muted / --accent).
+  var TOK={light:{bg:'#e3e7ee',fg:'#6b7280',link:'#2f6df6'},dark:{bg:'#272f3c',fg:'#9aa3b2',link:'#5b8cff'}};
+  function byName(n){return document.querySelector('[name="'+n+'"]');}
+  var allOn=byName('override_all_on'), darkOn=byName('override_dark_on');
+  if(!allOn||!darkOn){return;}
+  var f={ab:byName('override_bg'),af:byName('override_fg'),al:byName('override_link'),db:byName('override_bg_dark'),df:byName('override_fg_dark'),dl:byName('override_link_dark')};
+  var lightEl=document.getElementById('prev-light'), darkEl=document.getElementById('prev-dark');
+  function hexToRgb(h){h=h.replace('#','');return [parseInt(h.slice(0,2),16),parseInt(h.slice(2,4),16),parseInt(h.slice(4,6),16)];}
+  function pad(x){x=Math.max(0,Math.min(255,Math.round(x))).toString(16);return x.length<2?'0'+x:x;}
+  function rgbToHex(r){return '#'+pad(r[0])+pad(r[1])+pad(r[2]);}
+  function mix(a,b,t){return [a[0]+(b[0]-a[0])*t,a[1]+(b[1]-a[1])*t,a[2]+(b[2]-a[2])*t];}
+  function lum(r){return (0.2126*r[0]+0.7152*r[1]+0.0722*r[2])/255;}
+  // Derived border: nudge the background 14% toward black on a light bg, toward white on a dark bg.
+  function border(bg){var r=hexToRgb(bg);return rgbToHex(mix(r, lum(r)>0.5?[0,0,0]:[255,255,255], 0.14));}
+  function paint(el,c){
+    el.style.background=c.bg; el.style.color=c.fg;
+    el.style.borderTop='1px solid '+border(c.bg); el.style.borderBottom='1px solid '+border(c.bg);
+    var a=el.querySelector('.ad-link'); if(a){a.style.color=c.link;}
+  }
+  function resolve(){
+    var light=allOn.checked?{bg:f.ab.value,fg:f.af.value,link:f.al.value}:TOK.light;
+    var dark=darkOn.checked?{bg:f.db.value,fg:f.df.value,link:f.dl.value}
+            :(allOn.checked?{bg:f.ab.value,fg:f.af.value,link:f.al.value}:TOK.dark);
+    paint(lightEl,light); paint(darkEl,dark);
+    document.querySelectorAll('.ovr .swatches label').forEach(function(lab){
+      var inp=lab.querySelector('input[type=color]'), hx=lab.querySelector('.hex');
+      if(inp&&hx){hx.textContent=inp.value;}
+    });
+  }
+  function toggleGroup(chk){chk.closest('fieldset').querySelectorAll('[data-ovr-color]').forEach(function(inp){inp.disabled=!chk.checked;});}
+  [allOn,darkOn].forEach(function(chk){chk.addEventListener('change',function(){toggleGroup(chk);resolve();});});
+  Object.keys(f).forEach(function(k){f[k].addEventListener('input',resolve);});
+  resolve();
+})();
+</script>
 <form class="form" method="post" action="/_gm/banners/{{.ID}}/delete" onsubmit="return confirm('Delete this campaign and its messages?')">
 <button type="submit" class="danger">Delete campaign</button>
 </form>

backend/internal/adminconsole/views.go

@@ -498,15 +498,30 @@ type BannerCampaignRow struct {
 
 // BannerDetailView is the campaign detail/edit page. StartsAt/EndsAt are the
 // "YYYY-MM-DDTHH:MM" (UTC) values for the datetime-local inputs, empty when open.
+//
+// The colour-override and urgent fields drive the non-default campaign's editor:
+// OverrideAllOn/OverrideDarkOn report whether each colour set is active, and the
+// six *Bg/*Fg/*Link values seed the native colour inputs — the stored override
+// when a set is on, otherwise the neutral theme token so the picker starts from a
+// sensible colour and the live preview shows the real fallback.
 type BannerDetailView struct {
-	ID        string
+	ID             string
-	Name      string
+	Name           string
-	Weight    int
+	Weight         int
-	IsDefault bool
+	IsDefault      bool
-	Enabled   bool
+	Enabled        bool
-	StartsAt  string
+	StartsAt       string
-	EndsAt    string
+	EndsAt         string
-	Messages  []BannerMessageRow
+	Urgent         bool
+	OverrideAllOn  bool
+	AllBg          string
+	AllFg          string
+	AllLink        string
+	OverrideDarkOn bool
+	DarkBg         string
+	DarkFg         string
+	DarkLink       string
+	Messages       []BannerMessageRow
 }
 
 // BannerMessageRow is one bilingual message of a campaign. First/Last drive the

backend/internal/ads/ads.go

@@ -30,6 +30,15 @@ var ErrDefaultImmutable = errors.New("ads: the default campaign cannot be modifi
 // window or message body).
 var ErrValidation = errors.New("ads: validation")
 
+// ColorSet is an optional per-campaign colour override for the banner strip:
+// background, foreground (text) and link, each a "#rrggbb" hex string. The three
+// are set together or the whole set is absent (a nil *ColorSet).
+type ColorSet struct {
+	Bg   string
+	Fg   string
+	Link string
+}
+
 // Campaign is one advertising placement order with its messages.
 type Campaign struct {
 	ID        uuid.UUID // uuid.Nil on create
@@ -40,6 +49,16 @@ type Campaign struct {
 	StartsAt  *time.Time // nil = open-ended start; always nil for the default
 	EndsAt    *time.Time // nil = open-ended end; always nil for the default
 	Messages  []Message
+	// OverrideAll paints the strip on every theme; OverrideDark, when set, further
+	// overrides the dark theme (the client resolves dark ← dark ?? all ?? token,
+	// light ← all ?? token). Both are nil for the default campaign and for a
+	// campaign that keeps the neutral theme tokens. Non-default only.
+	OverrideAll  *ColorSet
+	OverrideDark *ColorSet
+	// Urgent forces the banner on every viewer (bypassing eligibility) and, while
+	// any urgent campaign is active, suppresses every non-urgent campaign and the
+	// default remainder. Non-default only; always false for the default campaign.
+	Urgent    bool
 	CreatedAt time.Time
 	UpdatedAt time.Time
 }
@@ -70,10 +89,15 @@ type Timings struct {
 
 // ActiveCampaign is one campaign in the resolved rotation feed sent to a client:
 // its GCD-reduced show weight and its messages, already resolved to the viewer's
-// language and in display (round-robin) order.
+// language and in display (round-robin) order, plus the optional colour overrides
+// the client applies to the strip (nil = the neutral theme tokens). Urgency is not
+// carried here: it is resolved server-side into the set's membership and the
+// eligibility bypass, so the client only ever renders what it is sent.
 type ActiveCampaign struct {
-	Weight   int
+	Weight       int
-	Messages []string
+	Messages     []string
+	OverrideAll  *ColorSet
+	OverrideDark *ColorSet
 }
 
 // Eligible reports whether an account should be shown the advertising banner: a
@@ -85,14 +109,20 @@ func Eligible(paidAccount bool, hintBalance int, hasNoBanner bool) bool {
 }
 
 // computeActiveSet builds the resolved rotation feed from the enabled campaigns
-// at time now, in language lang. Campaigns outside their validity window, and
+// at time now, in language lang, and reports whether the feed is an urgent one.
-// campaigns with no messages, are dropped. The default campaign's effective
+// Campaigns outside their validity window, and campaigns with no messages, are
-// weight is the remainder up to 100% — max(0, 100 - sum of active timed
+// dropped.
-// weights) — so it fills unsold inventory and is dropped entirely when timed
+//
-// campaigns already reach 100%. Weights are then reduced by their GCD so the
+// While any active campaign is urgent, the feed is the urgent campaigns alone —
-// fair rotation cycle stays short. The input is expected to be the enabled
+// every non-urgent timed campaign and the default remainder are suppressed for
-// campaigns (ActiveCampaigns); disabled ones must already be excluded.
+// the duration (and the caller shows the feed to every viewer, bypassing
-func computeActiveSet(campaigns []Campaign, now time.Time, lang string) []ActiveCampaign {
+// eligibility). Otherwise the default campaign's effective weight is the
+// remainder up to 100% — max(0, 100 - sum of active timed weights) — so it fills
+// unsold inventory and is dropped entirely when timed campaigns already reach
+// 100%. Weights are then reduced by their GCD so the fair rotation cycle stays
+// short. The input is expected to be the enabled campaigns (ActiveCampaigns);
+// disabled ones must already be excluded.
+func computeActiveSet(campaigns []Campaign, now time.Time, lang string) ([]ActiveCampaign, bool) {
 	var timed []Campaign
 	var def *Campaign
 	for i := range campaigns {
@@ -108,20 +138,54 @@ func computeActiveSet(campaigns []Campaign, now time.Time, lang string) []Active
 			timed = append(timed, c)
 		}
 	}
+	if urgent := filterUrgent(timed); len(urgent) > 0 {
+		out := make([]ActiveCampaign, 0, len(urgent))
+		for _, c := range urgent {
+			out = append(out, activeFrom(c, lang))
+		}
+		reduceByGCD(out)
+		return out, true
+	}
 	sumTimed := 0
 	for _, c := range timed {
 		sumTimed += c.Weight
 	}
 	out := make([]ActiveCampaign, 0, len(timed)+1)
 	for _, c := range timed {
-		out = append(out, ActiveCampaign{Weight: c.Weight, Messages: resolveBodies(c.Messages, lang)})
+		out = append(out, activeFrom(c, lang))
 	}
 	if def != nil {
 		if dw := 100 - sumTimed; dw > 0 {
-			out = append(out, ActiveCampaign{Weight: dw, Messages: resolveBodies(def.Messages, lang)})
+			a := activeFrom(*def, lang)
+			a.Weight = dw // the default's stored weight is nominal; it fills the remainder
+			out = append(out, a)
 		}
 	}
 	reduceByGCD(out)
+	return out, false
+}
+
+// activeFrom projects a campaign to its rotation-feed entry: its show weight, its
+// language-resolved messages and its colour overrides (carried through by
+// reference, they are read-only).
+func activeFrom(c Campaign, lang string) ActiveCampaign {
+	return ActiveCampaign{
+		Weight:       c.Weight,
+		Messages:     resolveBodies(c.Messages, lang),
+		OverrideAll:  c.OverrideAll,
+		OverrideDark: c.OverrideDark,
+	}
+}
+
+// filterUrgent returns the urgent campaigns among cs, preserving order. It is the
+// preempt selector: a non-empty result makes the whole feed urgent.
+func filterUrgent(cs []Campaign) []Campaign {
+	var out []Campaign
+	for _, c := range cs {
+		if c.Urgent {
+			out = append(out, c)
+		}
+	}
 	return out
 }
 

backend/internal/ads/ads_test.go

@@ -46,12 +46,19 @@ func TestComputeActiveSet(t *testing.T) {
 	timed := func(name string, weight int, starts, ends *time.Time, msgs []Message) Campaign {
 		return Campaign{Name: name, Weight: weight, Enabled: true, StartsAt: starts, EndsAt: ends, Messages: msgs}
 	}
+	urgent := func(name string, weight int, msgs []Message) Campaign {
+		c := timed(name, weight, nil, nil, msgs)
+		c.Urgent = true
+		return c
+	}
+	red := &ColorSet{Bg: "#aa0000", Fg: "#ffffff", Link: "#ffdd00"}
 
 	tests := []struct {
-		name      string
+		name       string
-		campaigns []Campaign
+		campaigns  []Campaign
-		lang      string
+		lang       string
-		want      []ActiveCampaign
+		want       []ActiveCampaign
+		wantUrgent bool
 	}{
 		{
 			name:      "default only reduces to weight 1",
@@ -152,22 +159,71 @@ func TestComputeActiveSet(t *testing.T) {
 			lang: "en",
 			want: []ActiveCampaign{{Weight: 1, Messages: []string{"one-en", "two-en"}}},
 		},
+		{
+			name: "urgent preempts default and normal timed",
+			campaigns: []Campaign{
+				def(msg("house")),
+				timed("promo", 40, nil, nil, msg("promo")),
+				urgent("alert", 50, msg("alert")),
+			},
+			lang: "en",
+			// only the urgent campaign survives; a lone weight reduces to 1.
+			want:       []ActiveCampaign{{Weight: 1, Messages: []string{"alert-en"}}},
+			wantUrgent: true,
+		},
+		{
+			name: "multiple urgent share the feed by gcd",
+			campaigns: []Campaign{
+				def(msg("house")),
+				urgent("a", 60, msg("a")),
+				urgent("b", 40, msg("b")),
+			},
+			lang: "en",
+			// default and any non-urgent dropped; gcd(60,40)=20 -> 3 and 2.
+			want: []ActiveCampaign{
+				{Weight: 3, Messages: []string{"a-en"}},
+				{Weight: 2, Messages: []string{"b-en"}},
+			},
+			wantUrgent: true,
+		},
+		{
+			name: "out-of-window urgent does not preempt",
+			campaigns: []Campaign{
+				def(msg("house")),
+				func() Campaign { c := urgent("future", 50, msg("future")); c.StartsAt = &future; return c }(),
+			},
+			lang: "en",
+			// the urgent campaign is not yet live, so the normal default feed stands.
+			want: []ActiveCampaign{{Weight: 1, Messages: []string{"house-en"}}},
+		},
+		{
+			name: "colour overrides ride the active campaign",
+			campaigns: []Campaign{
+				def(msg("house")),
+				func() Campaign { c := timed("promo", 100, nil, nil, msg("promo")); c.OverrideAll = red; return c }(),
+			},
+			lang: "en",
+			want: []ActiveCampaign{{Weight: 1, Messages: []string{"promo-en"}, OverrideAll: red}},
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := computeActiveSet(tt.campaigns, now, tt.lang)
+			got, gotUrgent := computeActiveSet(tt.campaigns, now, tt.lang)
 			if !reflect.DeepEqual(got, tt.want) {
 				t.Errorf("computeActiveSet() =\n  %#v\nwant\n  %#v", got, tt.want)
 			}
+			if gotUrgent != tt.wantUrgent {
+				t.Errorf("computeActiveSet() urgent = %v, want %v", gotUrgent, tt.wantUrgent)
+			}
 		})
 	}
 }
 
 func TestComputeActiveSetEmpty(t *testing.T) {
 	// No campaigns at all yields an empty (non-nil-or-nil) feed without panicking.
-	if got := computeActiveSet(nil, time.Now(), "en"); len(got) != 0 {
+	if got, urgent := computeActiveSet(nil, time.Now(), "en"); len(got) != 0 || urgent {
-		t.Errorf("computeActiveSet(nil) = %#v, want empty", got)
+		t.Errorf("computeActiveSet(nil) = %#v urgent=%v, want empty non-urgent", got, urgent)
 	}
 }
 

backend/internal/ads/service.go

@@ -3,6 +3,7 @@ package ads
 import (
 	"context"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
@@ -40,17 +41,20 @@ func NewService(store *Store) *Service { return &Service{store: store} }
 // ActiveSet returns the resolved rotation feed for a viewer in language lang
 // (en/ru) together with the global display timings: the currently-active
 // campaigns, each with its GCD-reduced show weight and its messages resolved to
-// lang, ready for the client's weighted round-robin.
+// lang, ready for the client's weighted round-robin. The bool result reports
-func (s *Service) ActiveSet(ctx context.Context, lang string) ([]ActiveCampaign, Timings, error) {
+// whether the feed is urgent — an urgent feed is shown to every viewer
+// regardless of eligibility (the caller skips the eligibility gate for it).
+func (s *Service) ActiveSet(ctx context.Context, lang string) ([]ActiveCampaign, Timings, bool, error) {
 	campaigns, err := s.store.ActiveCampaigns(ctx)
 	if err != nil {
-		return nil, Timings{}, err
+		return nil, Timings{}, false, err
 	}
 	timings, err := s.store.Settings(ctx)
 	if err != nil {
-		return nil, Timings{}, err
+		return nil, Timings{}, false, err
 	}
-	return computeActiveSet(campaigns, time.Now().UTC(), lang), timings, nil
+	set, urgent := computeActiveSet(campaigns, time.Now().UTC(), lang)
+	return set, timings, urgent, nil
 }
 
 // ListCampaigns returns every campaign with its messages, for the admin console.
@@ -76,8 +80,13 @@ func (s *Service) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, er
 	if err := validWindow(c.StartsAt, c.EndsAt); err != nil {
 		return uuid.Nil, err
 	}
+	all, dark, err := validOverrides(c.OverrideAll, c.OverrideDark)
+	if err != nil {
+		return uuid.Nil, err
+	}
 	return s.store.CreateCampaign(ctx, Campaign{
 		Name: name, Weight: c.Weight, Enabled: c.Enabled, StartsAt: c.StartsAt, EndsAt: c.EndsAt,
+		OverrideAll: all, OverrideDark: dark, Urgent: c.Urgent,
 	})
 }
 
@@ -99,6 +108,7 @@ func (s *Service) UpdateCampaign(ctx context.Context, c Campaign) error {
 		upd.Enabled = true
 		upd.StartsAt = nil
 		upd.EndsAt = nil
+		// The default (house) campaign stays plain: no colour overrides, never urgent.
 	} else {
 		if err := validWeight(c.Weight); err != nil {
 			return err
@@ -106,10 +116,17 @@ func (s *Service) UpdateCampaign(ctx context.Context, c Campaign) error {
 		if err := validWindow(c.StartsAt, c.EndsAt); err != nil {
 			return err
 		}
+		all, dark, err := validOverrides(c.OverrideAll, c.OverrideDark)
+		if err != nil {
+			return err
+		}
 		upd.Weight = c.Weight
 		upd.Enabled = c.Enabled
 		upd.StartsAt = c.StartsAt
 		upd.EndsAt = c.EndsAt
+		upd.OverrideAll = all
+		upd.OverrideDark = dark
+		upd.Urgent = c.Urgent
 	}
 	return s.store.UpdateCampaign(ctx, upd)
 }
@@ -254,6 +271,46 @@ func validWindow(starts, ends *time.Time) error {
 	return nil
 }
 
+// hexColor matches a "#rrggbb" colour — the format the console's native colour
+// input emits and the wire carries.
+var hexColor = regexp.MustCompile(`^#[0-9a-fA-F]{6}$`)
+
+// validOverrides validates the two optional colour sets together and returns
+// their normalised copies (nil when a set is absent), so a caller can store them
+// directly.
+func validOverrides(all, dark *ColorSet) (*ColorSet, *ColorSet, error) {
+	va, err := validColorSet(all)
+	if err != nil {
+		return nil, nil, err
+	}
+	vd, err := validColorSet(dark)
+	if err != nil {
+		return nil, nil, err
+	}
+	return va, vd, nil
+}
+
+// validColorSet validates one optional colour override: a nil set passes (no
+// override); otherwise all three colours must be present and "#rrggbb". It
+// returns a trimmed, lower-cased copy.
+func validColorSet(cs *ColorSet) (*ColorSet, error) {
+	if cs == nil {
+		return nil, nil
+	}
+	bg := strings.TrimSpace(cs.Bg)
+	fg := strings.TrimSpace(cs.Fg)
+	link := strings.TrimSpace(cs.Link)
+	if bg == "" || fg == "" || link == "" {
+		return nil, fmt.Errorf("%w: a colour override needs all of background, text and link", ErrValidation)
+	}
+	for _, h := range []string{bg, fg, link} {
+		if !hexColor.MatchString(h) {
+			return nil, fmt.Errorf("%w: colours must be #rrggbb hex", ErrValidation)
+		}
+	}
+	return &ColorSet{Bg: strings.ToLower(bg), Fg: strings.ToLower(fg), Link: strings.ToLower(link)}, nil
+}
+
 // validBodies trims and bounds both mandatory language bodies of a message.
 func validBodies(bodyEn, bodyRu string) (string, string, error) {
 	en := strings.TrimSpace(bodyEn)

backend/internal/ads/store.go

@@ -90,15 +90,23 @@ func (s *Store) Campaign(ctx context.Context, id uuid.UUID) (Campaign, error) {
 func (s *Store) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, error) {
 	id := uuid.New()
 	now := time.Now().UTC()
+	abg, afg, alink := colorCols(c.OverrideAll)
+	dbg, dfg, dlink := colorCols(c.OverrideDark)
 	stmt := table.AdCampaigns.INSERT(
 		table.AdCampaigns.CampaignID, table.AdCampaigns.Name, table.AdCampaigns.Weight,
 		table.AdCampaigns.IsDefault, table.AdCampaigns.Enabled,
 		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt,
+		table.AdCampaigns.OverrideBg, table.AdCampaigns.OverrideFg, table.AdCampaigns.OverrideLink,
+		table.AdCampaigns.OverrideBgDark, table.AdCampaigns.OverrideFgDark, table.AdCampaigns.OverrideLinkDark,
+		table.AdCampaigns.Urgent,
 		table.AdCampaigns.CreatedAt, table.AdCampaigns.UpdatedAt,
 	).VALUES(
 		postgres.UUID(id), postgres.String(c.Name), postgres.Int(int64(c.Weight)),
 		postgres.Bool(false), postgres.Bool(c.Enabled),
 		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt),
+		abg, afg, alink,
+		dbg, dfg, dlink,
+		postgres.Bool(c.Urgent),
 		postgres.TimestampzT(now), postgres.TimestampzT(now),
 	)
 	if _, err := stmt.ExecContext(ctx, s.db); err != nil {
@@ -111,12 +119,20 @@ func (s *Store) CreateCampaign(ctx context.Context, c Campaign) (uuid.UUID, erro
 // window. The default flag is never touched here. Returns ErrNotFound when no
 // campaign matches.
 func (s *Store) UpdateCampaign(ctx context.Context, c Campaign) error {
+	abg, afg, alink := colorCols(c.OverrideAll)
+	dbg, dfg, dlink := colorCols(c.OverrideDark)
 	stmt := table.AdCampaigns.UPDATE(
 		table.AdCampaigns.Name, table.AdCampaigns.Weight, table.AdCampaigns.Enabled,
-		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt, table.AdCampaigns.UpdatedAt,
+		table.AdCampaigns.StartsAt, table.AdCampaigns.EndsAt,
+		table.AdCampaigns.OverrideBg, table.AdCampaigns.OverrideFg, table.AdCampaigns.OverrideLink,
+		table.AdCampaigns.OverrideBgDark, table.AdCampaigns.OverrideFgDark, table.AdCampaigns.OverrideLinkDark,
+		table.AdCampaigns.Urgent, table.AdCampaigns.UpdatedAt,
 	).SET(
 		postgres.String(c.Name), postgres.Int(int64(c.Weight)), postgres.Bool(c.Enabled),
-		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt), postgres.TimestampzT(time.Now().UTC()),
+		tsOrNull(c.StartsAt), tsOrNull(c.EndsAt),
+		abg, afg, alink,
+		dbg, dfg, dlink,
+		postgres.Bool(c.Urgent), postgres.TimestampzT(time.Now().UTC()),
 	).WHERE(table.AdCampaigns.CampaignID.EQ(postgres.UUID(c.ID)))
 	return execOne(ctx, s.db, stmt, "update campaign")
 }
@@ -257,18 +273,40 @@ func execOne(ctx context.Context, db qrm.Executable, stmt postgres.Statement, wh
 
 func modelToCampaign(r model.AdCampaigns) Campaign {
 	return Campaign{
-		ID:        r.CampaignID,
+		ID:           r.CampaignID,
-		Name:      r.Name,
+		Name:         r.Name,
-		Weight:    int(r.Weight),
+		Weight:       int(r.Weight),
-		IsDefault: r.IsDefault,
+		IsDefault:    r.IsDefault,
-		Enabled:   r.Enabled,
+		Enabled:      r.Enabled,
-		StartsAt:  r.StartsAt,
+		StartsAt:     r.StartsAt,
-		EndsAt:    r.EndsAt,
+		EndsAt:       r.EndsAt,
-		CreatedAt: r.CreatedAt,
+		OverrideAll:  colorSetFrom(r.OverrideBg, r.OverrideFg, r.OverrideLink),
-		UpdatedAt: r.UpdatedAt,
+		OverrideDark: colorSetFrom(r.OverrideBgDark, r.OverrideFgDark, r.OverrideLinkDark),
+		Urgent:       r.Urgent,
+		CreatedAt:    r.CreatedAt,
+		UpdatedAt:    r.UpdatedAt,
 	}
 }
 
+// colorSetFrom rebuilds an optional ColorSet from three nullable colour columns.
+// The all-or-nothing CHECK keeps the trio consistent, so a nil in any one means
+// the set is absent.
+func colorSetFrom(bg, fg, link *string) *ColorSet {
+	if bg == nil || fg == nil || link == nil {
+		return nil
+	}
+	return &ColorSet{Bg: *bg, Fg: *fg, Link: *link}
+}
+
+// colorCols renders a *ColorSet as its three column value-expressions in
+// bg, fg, link order — NULL for each when the set is absent.
+func colorCols(cs *ColorSet) (bg, fg, link postgres.Expression) {
+	if cs == nil {
+		return postgres.NULL, postgres.NULL, postgres.NULL
+	}
+	return postgres.String(cs.Bg), postgres.String(cs.Fg), postgres.String(cs.Link)
+}
+
 func modelToMessage(r model.AdMessages) Message {
 	return Message{
 		ID:         r.MessageID,

backend/internal/engine/endfixture_test.go

@@ -0,0 +1,123 @@
+package engine
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitea.iliadenisov.ru/developer/scrabble-solver/rules"
+)
+
+// The offline engine (ui/src/lib/localgame) reproduces the end-of-game rack settlement and the
+// winner rule so a local game finishes with the same scores as the server. These golden fixtures
+// pin the ported pure functions (applyEndAdjustment / winner / rackValue) to the real Go engine.
+// Being in-package, this emitter constructs Game values directly and drives the unexported
+// end-game math on chosen positions.
+
+type endCaseIn struct {
+	Name     string  `json:"name"`
+	Variant  string  `json:"variant"`
+	Reason   string  `json:"reason"`
+	Hands    [][]int `json:"hands"`
+	Scores   []int   `json:"scores"`
+	Resigned []bool  `json:"resigned"`
+	ToMove   int     `json:"toMove"`
+}
+
+type endCaseOut struct {
+	endCaseIn
+	ScoresAfter []int `json:"scoresAfter"`
+	Winner      int   `json:"winner"`
+}
+
+func rulesetFor(variant string) *rules.Ruleset {
+	switch variant {
+	case "scrabble_ru":
+		return rules.RussianScrabble()
+	case "erudit_ru":
+		return rules.Erudit()
+	default:
+		return rules.English()
+	}
+}
+
+func reasonFor(s string) EndReason {
+	switch s {
+	case "out_of_tiles":
+		return EndOutOfTiles
+	case "scoreless":
+		return EndScoreless
+	case "resign":
+		return EndResign
+	case "aborted":
+		return EndAborted
+	}
+	return EndNotOver
+}
+
+func handsBytes(hands [][]int) [][]byte {
+	out := make([][]byte, len(hands))
+	for i, h := range hands {
+		b := make([]byte, len(h))
+		for j, x := range h {
+			b[j] = byte(x)
+		}
+		out[i] = b
+	}
+	return out
+}
+
+// TestEmitEndgameFixtures regenerates ui/src/lib/localgame/testdata/endgame.json. Gated by
+// EMIT_ENGINE_FIXTURES. Regenerate with:
+//
+//	EMIT_ENGINE_FIXTURES=1 go test ./backend/internal/engine -run TestEmitEndgameFixtures
+func TestEmitEndgameFixtures(t *testing.T) {
+	if os.Getenv("EMIT_ENGINE_FIXTURES") == "" {
+		t.Skip("set EMIT_ENGINE_FIXTURES=1 to regenerate ui/src/lib/localgame/testdata/endgame.json")
+	}
+
+	cases := []endCaseIn{
+		{"out-basic", "scrabble_en", "out_of_tiles", [][]int{{}, {0, 1, 2}}, []int{50, 40}, []bool{false, false}, 0},
+		{"out-blank", "scrabble_en", "out_of_tiles", [][]int{{}, {255, 0}}, []int{30, 30}, []bool{false, false}, 0},
+		{"out-erudit-yo", "erudit_ru", "out_of_tiles", [][]int{{}, {6, 32}}, []int{10, 10}, []bool{false, false}, 0},
+		{"out-tie", "scrabble_en", "out_of_tiles", [][]int{{}, {}}, []int{30, 30}, []bool{false, false}, 0},
+		{"out-3p", "scrabble_ru", "out_of_tiles", [][]int{{}, {0, 1}, {2}}, []int{10, 10, 10}, []bool{false, false, false}, 0},
+		{"scoreless", "scrabble_en", "scoreless", [][]int{{0, 1}, {2, 3}}, []int{20, 20}, []bool{false, false}, 0},
+		{"resign-2p", "scrabble_en", "resign", [][]int{{}, {0}}, []int{100, 10}, []bool{true, false}, 1},
+		{"resign-3p", "scrabble_en", "resign", [][]int{{}, {}, {}}, []int{50, 60, 40}, []bool{false, true, false}, 0},
+		{"aborted", "scrabble_en", "aborted", [][]int{{0}, {1}}, []int{40, 30}, []bool{false, false}, 0},
+	}
+
+	out := make([]endCaseOut, 0, len(cases))
+	for _, c := range cases {
+		rs := rulesetFor(c.Variant)
+		scores := append([]int(nil), c.Scores...)
+		g := &Game{
+			rules:    rs,
+			hands:    handsBytes(c.Hands),
+			scores:   scores,
+			resigned: c.Resigned,
+			toMove:   c.ToMove,
+		}
+		reason := reasonFor(c.Reason)
+		g.over = true
+		g.reason = reason
+		g.applyEndAdjustment(reason)
+		out = append(out, endCaseOut{endCaseIn: c, ScoresAfter: g.scores, Winner: g.winner()})
+	}
+
+	dir := filepath.Join("..", "..", "..", "ui", "src", "lib", "localgame", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatalf("mkdir %s: %v", dir, err)
+	}
+	data, err := json.MarshalIndent(map[string]any{"cases": out}, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	path := filepath.Join(dir, "endgame.json")
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		t.Fatalf("write %s: %v", path, err)
+	}
+	t.Logf("wrote %s (%d cases)", path, len(out))
+}

backend/internal/game/helpers_test.go

@@ -69,6 +69,29 @@ func TestHintsRemaining(t *testing.T) {
 	}
 }
 
+func TestHintUnlockLeftSeconds(t *testing.T) {
+	now := time.Now()
+	// A gated vs_ai game on the caller's turn, the robot having moved 10 min ago (turn started then).
+	gated := Game{VsAI: true, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-10 * time.Minute)}
+	cases := []struct {
+		name string
+		g    Game
+		seat int
+		want int
+	}{
+		{"non-vs_ai is open", Game{VsAI: false, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-10 * time.Minute)}, 0, 0},
+		{"not the caller's turn is open", gated, 1, 0},
+		{"human first move (no robot move) is open", Game{VsAI: true, ToMove: 0, MoveCount: 0, TurnStartedAt: now}, 0, 0},
+		{"robot moved 10 min ago leaves 20 min", gated, 0, 20 * 60},
+		{"robot moved past the window is open", Game{VsAI: true, ToMove: 0, MoveCount: 2, TurnStartedAt: now.Add(-40 * time.Minute)}, 0, 0},
+	}
+	for _, c := range cases {
+		if got := hintUnlockLeftSeconds(c.g, c.seat, now); got != c.want {
+			t.Errorf("%s: hintUnlockLeftSeconds = %d, want %d", c.name, got, c.want)
+		}
+	}
+}
+
 func TestAllowedTimeout(t *testing.T) {
 	if !allowedTimeout(24 * time.Hour) {
 		t.Error("24h must be allowed")

backend/internal/game/service.go

@@ -1058,10 +1058,31 @@ func (svc *Service) MarkChangesApplied(ctx context.Context, variant engine.Varia
 	return svc.store.MarkChangesApplied(ctx, variant.String(), version)
 }
 
-// Hint reveals the top-scoring legal play for the requesting player on their
+// hintIdleWindow is how long a vs_ai player must be stuck on a turn (since the robot's last move)
-// turn, spending one hint from their per-game allowance and then their profile
+// before the idle hint unlocks. Mirrors the offline client (lib/hints HINT_GATE_MS = 30 min).
-// wallet. It returns ErrHintsDisabled, ErrNoHintsLeft or ErrNoHintAvailable as
+const hintIdleWindow = 30 * time.Minute
-// appropriate.
+
+// hintUnlockLeftSeconds is the seconds until g's vs_ai idle hint unlocks for seat, measured from now:
+// the robot's last move (the current turn's start, on the human's turn) plus the window, floored at
+// 0 and ceiled to whole seconds. It is 0 for a non-vs_ai game, when it is not seat's turn, or on the
+// human's first move (MoveCount 0, no robot move yet) — the gate is an anti-frustration aid, not a
+// first-move tax. The client anchors a monotonic countdown to it, so a client clock cannot skew it.
+func hintUnlockLeftSeconds(g Game, seat int, now time.Time) int {
+	if !g.VsAI || g.ToMove != seat || g.MoveCount < 1 {
+		return 0
+	}
+	left := g.TurnStartedAt.Add(hintIdleWindow).Sub(now)
+	if left <= 0 {
+		return 0
+	}
+	return int((left + time.Second - 1) / time.Second) // ceil to whole seconds (no math import)
+}
+
+// Hint reveals the top-scoring legal play for the requesting player on their turn. For a human game
+// it spends one hint from the per-game allowance then the profile wallet (ErrHintsDisabled /
+// ErrNoHintsLeft / ErrNoHintAvailable). For a vs_ai game the hint is unlimited and wallet-free but
+// idle-gated from the server clock (ErrHintLocked until the window elapses) and counts toward no
+// hint statistic.
 func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (HintResult, error) {
 	pre, err := svc.store.GetGame(ctx, gameID)
 	if err != nil {
@@ -1080,6 +1101,26 @@ func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (Hint
 	if !pre.HintsAllowed {
 		return HintResult{}, ErrHintsDisabled
 	}
+	if pre.VsAI {
+		// vs_ai: unlimited and wallet-free, but idle-gated from the server clock — and counted toward
+		// no hint statistic. Enforce the gate (the client normally pre-gates from the view's
+		// HintUnlockLeftSeconds; this is the authoritative backstop), then serve the top move without
+		// touching the allowance, the wallet or hints_used.
+		if hintUnlockLeftSeconds(pre, seat, svc.clock()) > 0 {
+			return HintResult{}, ErrHintLocked
+		}
+		unlock := svc.locks.lock(gameID)
+		defer unlock()
+		g, err := svc.liveGame(ctx, pre)
+		if err != nil {
+			return HintResult{}, err
+		}
+		move, ok := g.HintView()
+		if !ok {
+			return HintResult{}, ErrNoHintAvailable
+		}
+		return HintResult{Move: move}, nil
+	}
 	acc, err := svc.accounts.GetByID(ctx, accountID)
 	if err != nil {
 		return HintResult{}, err
@@ -1208,6 +1249,8 @@ func (svc *Service) GameState(ctx context.Context, gameID, accountID uuid.UUID)
 		BagLen:         g.BagLen(),
 		HintsRemaining: hintsRemaining(pre.HintsPerPlayer, pre.Seats[seat].HintsUsed, acc.HintBalance),
 		WalletBalance:  acc.HintBalance,
+		// vs_ai idle-hint gate (seconds left; 0 for a human game / first move / not your turn).
+		HintUnlockLeftSeconds: hintUnlockLeftSeconds(pre, seat, svc.clock()),
 	}, nil
 }
 

backend/internal/game/types.go

@@ -65,6 +65,10 @@ var (
 	ErrNoHintsLeft = errors.New("game: no hints remaining")
 	// ErrNoHintAvailable is returned when the player has no legal play to reveal.
 	ErrNoHintAvailable = errors.New("game: no legal move to suggest")
+	// ErrHintLocked is returned when a vs_ai game's idle hint is still gated (the player has not yet
+	// been stuck the idle window since the robot's last move). The client normally pre-gates from
+	// StateView.HintUnlockLeftSeconds, so this is the authoritative server-clock backstop.
+	ErrHintLocked = errors.New("game: hint is not available yet")
 	// ErrGameLimitReached is returned when an account already holds MaxActiveQuickGames
 	// simultaneous quick games and tries to create another game (quick or by invitation).
 	ErrGameLimitReached = errors.New("game: simultaneous game limit reached")
@@ -240,6 +244,11 @@ type StateView struct {
 	// WalletBalance is the player's global hint-wallet balance alone (HintsRemaining folds
 	// it in with the per-game allowance), so the client keeps the wallet live across games.
 	WalletBalance int
+	// HintUnlockLeftSeconds is, for a vs_ai game on the requesting player's turn, the seconds left
+	// until the idle hint unlocks (the robot's last move plus the idle window, from the server clock);
+	// 0 for the human's first move, when it is not their turn, or a non-vs_ai game. The vs_ai hint is
+	// unlimited and wallet-free; this idle gate replaces the allowance/wallet for it.
+	HintUnlockLeftSeconds int
 }
 
 // HistoryMove is one decoded journal row, independent of any dictionary.

backend/internal/inttest/banner_console_test.go

@@ -192,8 +192,9 @@ func TestBannerMessageOwnership(t *testing.T) {
 type profileBanner struct {
 	Banner *struct {
 		Campaigns []struct {
-			Weight   int      `json:"weight"`
+			Weight     int      `json:"weight"`
-			Messages []string `json:"messages"`
+			Messages   []string `json:"messages"`
+			OverrideBg string   `json:"override_bg"`
 		} `json:"campaigns"`
 		Timings struct {
 			HoldMs int `json:"hold_ms"`
@@ -274,3 +275,142 @@ func TestBannerSurvivesProfileUpdate(t *testing.T) {
 		t.Fatalf("profile update dropped the banner block: %v", p.Banner)
 	}
 }
+
+// TestBannerConsoleColorsAndUrgent drives the colour-override + urgent editor over
+// HTTP against real Postgres: an incomplete or malformed colour set is refused, a
+// full two-set override + urgent round-trips through the store (exercising the new
+// columns and CHECK constraints), clearing the sets removes the override, and the
+// default campaign stays plain (colours + urgent are ignored for it).
+func TestBannerConsoleColorsAndUrgent(t *testing.T) {
+	ctx := context.Background()
+	srv, adsSvc := bannerServer(t)
+	h := srv.Handler()
+	base := "http://admin.test/_gm"
+	const origin = "http://admin.test"
+
+	name := "Brand-" + uuid.NewString()[:8]
+	if code, body := consoleDo(h, http.MethodPost, base+"/banners", "name="+name+"&weight=20&enabled=on", origin); code != http.StatusOK || !strings.Contains(body, "Created") {
+		t.Fatalf("create = %d, has Created=%v", code, strings.Contains(body, "Created"))
+	}
+	id := findCampaign(t, adsSvc, name)
+	t.Cleanup(func() { _ = adsSvc.DeleteCampaign(ctx, id) })
+	detail := base + "/banners/" + id.String()
+
+	// A partial colour set (a missing colour) is refused by validation.
+	partial := "name=" + name + "&weight=20&enabled=on&override_all_on=on&override_bg=%23aa0000&override_fg=&override_link=%23ffdd00"
+	if code, b := consoleDo(h, http.MethodPost, detail, partial, origin); code != http.StatusOK || !strings.Contains(b, "Not saved") {
+		t.Fatalf("partial colour = %d, has 'Not saved'=%v", code, strings.Contains(b, "Not saved"))
+	}
+	// A malformed hex is refused.
+	badHex := "name=" + name + "&weight=20&enabled=on&override_all_on=on&override_bg=red&override_fg=%23ffffff&override_link=%23ffdd00"
+	if code, b := consoleDo(h, http.MethodPost, detail, badHex, origin); code != http.StatusOK || !strings.Contains(b, "Not saved") {
+		t.Fatalf("bad hex = %d, has 'Not saved'=%v", code, strings.Contains(b, "Not saved"))
+	}
+	// Both colour sets + urgent persist and round-trip through the store.
+	full := "name=" + name + "&weight=20&enabled=on&urgent=on" +
+		"&override_all_on=on&override_bg=%23aa0000&override_fg=%23ffffff&override_link=%23ffdd00" +
+		"&override_dark_on=on&override_bg_dark=%23330000&override_fg_dark=%23eeeeee&override_link_dark=%23ffcc00"
+	if code, b := consoleDo(h, http.MethodPost, detail, full, origin); code != http.StatusOK || !strings.Contains(b, "Saved") {
+		t.Fatalf("full save = %d, has Saved=%v", code, strings.Contains(b, "Saved"))
+	}
+	cm, err := adsSvc.Campaign(ctx, id)
+	if err != nil {
+		t.Fatalf("read campaign: %v", err)
+	}
+	if cm.OverrideAll == nil || cm.OverrideAll.Bg != "#aa0000" || cm.OverrideAll.Fg != "#ffffff" || cm.OverrideAll.Link != "#ffdd00" {
+		t.Fatalf("override all = %+v", cm.OverrideAll)
+	}
+	if cm.OverrideDark == nil || cm.OverrideDark.Bg != "#330000" || cm.OverrideDark.Fg != "#eeeeee" || cm.OverrideDark.Link != "#ffcc00" {
+		t.Fatalf("override dark = %+v", cm.OverrideDark)
+	}
+	if !cm.Urgent {
+		t.Fatal("urgent not persisted")
+	}
+	// Clearing the sets (both checkboxes off, urgent off) removes the override.
+	if code, _ := consoleDo(h, http.MethodPost, detail, "name="+name+"&weight=20&enabled=on", origin); code != http.StatusOK {
+		t.Fatalf("clear = %d", code)
+	}
+	if cm, _ := adsSvc.Campaign(ctx, id); cm.OverrideAll != nil || cm.OverrideDark != nil || cm.Urgent {
+		t.Fatalf("override not cleared: all=%v dark=%v urgent=%v", cm.OverrideAll, cm.OverrideDark, cm.Urgent)
+	}
+
+	// The default campaign stays plain: submitted colours + urgent are ignored for it.
+	def := defaultCampaign(t, adsSvc)
+	defForm := "name=Default+%28house%29&urgent=on&override_all_on=on&override_bg=%23aa0000&override_fg=%23ffffff&override_link=%23ffdd00"
+	if code, _ := consoleDo(h, http.MethodPost, base+"/banners/"+def.ID.String(), defForm, origin); code != http.StatusOK {
+		t.Fatalf("update default = %d", code)
+	}
+	if again := defaultCampaign(t, adsSvc); again.OverrideAll != nil || again.OverrideDark != nil || again.Urgent {
+		t.Fatalf("default not plain: all=%v dark=%v urgent=%v", again.OverrideAll, again.OverrideDark, again.Urgent)
+	}
+}
+
+// TestBannerUrgentBypassesEligibility checks the urgent flag at the profile level:
+// an urgent campaign preempts the feed (only it shows, with its colours) and reaches
+// every viewer — including the no_banner role and a non-empty hint wallet that
+// otherwise suppress the banner.
+func TestBannerUrgentBypassesEligibility(t *testing.T) {
+	ctx := context.Background()
+	srv, adsSvc := bannerServer(t)
+	accounts := account.NewStore(testDB)
+	id := provisionAccount(t)
+
+	urgentID, err := adsSvc.CreateCampaign(ctx, ads.Campaign{
+		Name: "Alert-" + uuid.NewString()[:8], Weight: 10, Enabled: true, Urgent: true,
+		OverrideAll: &ads.ColorSet{Bg: "#aa0000", Fg: "#ffffff", Link: "#ffdd00"},
+	})
+	if err != nil {
+		t.Fatalf("create urgent: %v", err)
+	}
+	t.Cleanup(func() { _ = adsSvc.DeleteCampaign(ctx, urgentID) })
+	if _, err := adsSvc.AddMessage(ctx, urgentID, "System maintenance tonight", "Ночью тех.работы"); err != nil {
+		t.Fatalf("add urgent message: %v", err)
+	}
+
+	get := func() profileBanner {
+		t.Helper()
+		rec := userGet(t, srv, "/api/v1/user/profile", id)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("profile = %d", rec.Code)
+		}
+		var p profileBanner
+		if err := json.Unmarshal(rec.Body.Bytes(), &p); err != nil {
+			t.Fatalf("decode: %v", err)
+		}
+		return p
+	}
+	assertUrgentOnly := func(what string, p profileBanner) {
+		t.Helper()
+		if p.Banner == nil {
+			t.Fatalf("%s: no banner", what)
+		}
+		if len(p.Banner.Campaigns) != 1 {
+			t.Fatalf("%s: %d campaigns, want only the urgent one (default preempted)", what, len(p.Banner.Campaigns))
+		}
+		c := p.Banner.Campaigns[0]
+		if len(c.Messages) != 1 || c.Messages[0] != "System maintenance tonight" {
+			t.Fatalf("%s: messages = %v, want only the urgent one", what, c.Messages)
+		}
+		if c.OverrideBg != "#aa0000" {
+			t.Fatalf("%s: override_bg = %q, want #aa0000", what, c.OverrideBg)
+		}
+	}
+
+	// A normal viewer sees only the urgent campaign (the default is preempted).
+	assertUrgentOnly("eligible", get())
+
+	// The no_banner role no longer suppresses it — urgent reaches everyone.
+	if err := accounts.GrantRole(ctx, id, account.RoleNoBanner); err != nil {
+		t.Fatalf("grant role: %v", err)
+	}
+	assertUrgentOnly("no_banner", get())
+	if err := accounts.RevokeRole(ctx, id, account.RoleNoBanner); err != nil {
+		t.Fatalf("revoke role: %v", err)
+	}
+
+	// A non-empty hint wallet no longer suppresses it either.
+	if _, err := accounts.GrantHints(ctx, id, 5); err != nil {
+		t.Fatalf("grant hints: %v", err)
+	}
+	assertUrgentOnly("hints", get())
+}

backend/internal/inttest/email_test.go

@@ -206,7 +206,7 @@ func TestEmailLoginFlow(t *testing.T) {
 	svc := account.NewEmailService(account.NewStore(testDB), mailer, "https://erudit-game.ru")
 	email := "login-" + uuid.NewString() + "@example.com"
 
-	accountID, err := svc.RequestLoginCode(ctx, email, "+02:00", "en")
+	accountID, err := svc.RequestLoginCode(ctx, email, "+02:00", "en", false)
 	if err != nil {
 		t.Fatalf("request login code: %v", err)
 	}
@@ -233,7 +233,7 @@ func TestEmailLoginFlow(t *testing.T) {
 	}
 
 	// A second login for the same email is the returning user: same account.
-	if _, err := svc.RequestLoginCode(ctx, email, "", "ru"); err != nil {
+	if _, err := svc.RequestLoginCode(ctx, email, "", "ru", false); err != nil {
 		t.Fatalf("second request: %v", err)
 	}
 	acc2, err := svc.LoginWithCode(ctx, email, sixDigit.FindString(mailer.lastBody))
@@ -255,7 +255,7 @@ func TestEmailLoginProvisionsGuestUntilConfirmed(t *testing.T) {
 	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 	email := "squat-" + uuid.NewString() + "@example.com"
 
-	id, err := svc.RequestLoginCode(ctx, email, "", "en")
+	id, err := svc.RequestLoginCode(ctx, email, "", "en", false)
 	if err != nil {
 		t.Fatalf("request login code: %v", err)
 	}
@@ -279,6 +279,34 @@ func TestEmailLoginProvisionsGuestUntilConfirmed(t *testing.T) {
 	}
 }
 
+// TestEmailLoginPWAOmitsLink: a login requested from an installed PWA (pwa=true) mails only the
+// code — no one-tap confirm link, which would otherwise open in a separate browser out of the
+// PWA's reach. A non-PWA request keeps the link.
+func TestEmailLoginPWAOmitsLink(t *testing.T) {
+	ctx := context.Background()
+	mailer := &capturingMailer{}
+	svc := account.NewEmailService(account.NewStore(testDB), mailer, "https://erudit-game.ru")
+
+	pwaEmail := "pwa-login-" + uuid.NewString() + "@example.com"
+	if _, err := svc.RequestLoginCode(ctx, pwaEmail, "", "en", true); err != nil {
+		t.Fatalf("pwa request login: %v", err)
+	}
+	if sixDigit.FindString(mailer.lastBody) == "" {
+		t.Errorf("pwa login mail must still carry the code, body %q", mailer.lastBody)
+	}
+	if confirmToken.MatchString(mailer.lastBody) {
+		t.Errorf("pwa login mail must omit the one-tap confirm link, body %q", mailer.lastBody)
+	}
+
+	webEmail := "web-login-" + uuid.NewString() + "@example.com"
+	if _, err := svc.RequestLoginCode(ctx, webEmail, "", "en", false); err != nil {
+		t.Fatalf("web request login: %v", err)
+	}
+	if !confirmToken.MatchString(mailer.lastBody) {
+		t.Errorf("non-pwa login mail must keep the one-tap confirm link, body %q", mailer.lastBody)
+	}
+}
+
 // confirmToken extracts the one-tap deeplink token from the /app/#/confirm/<token> link
 // the branded email carries.
 var confirmToken = regexp.MustCompile(`/confirm/([A-Za-z0-9_-]+)`)
@@ -301,7 +329,7 @@ func TestConfirmByTokenLogin(t *testing.T) {
 	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 	email := "tok-login-" + uuid.NewString() + "@example.com"
 
-	id, err := svc.RequestLoginCode(ctx, email, "", "en")
+	id, err := svc.RequestLoginCode(ctx, email, "", "en", false)
 	if err != nil {
 		t.Fatalf("request login: %v", err)
 	}
@@ -382,7 +410,7 @@ func TestEmailAccountSeedsDisplayName(t *testing.T) {
 	svc := account.NewEmailService(store, &capturingMailer{}, "https://erudit-game.ru")
 	local := "kaya-" + uuid.NewString()[:8]
 
-	id, err := svc.RequestLoginCode(ctx, local+"@example.com", "", "en")
+	id, err := svc.RequestLoginCode(ctx, local+"@example.com", "", "en", false)
 	if err != nil {
 		t.Fatalf("request login: %v", err)
 	}

backend/internal/postgres/jet/backend/model/ad_campaigns.go

@@ -13,13 +13,20 @@ import (
 )
 
 type AdCampaigns struct {
-	CampaignID uuid.UUID `sql:"primary_key"`
+	CampaignID       uuid.UUID `sql:"primary_key"`
-	Name       string
+	Name             string
-	Weight     int32
+	Weight           int32
-	IsDefault  bool
+	IsDefault        bool
-	Enabled    bool
+	Enabled          bool
-	StartsAt   *time.Time
+	StartsAt         *time.Time
-	EndsAt     *time.Time
+	EndsAt           *time.Time
-	CreatedAt  time.Time
+	CreatedAt        time.Time
-	UpdatedAt  time.Time
+	UpdatedAt        time.Time
+	OverrideBg       *string
+	OverrideFg       *string
+	OverrideLink     *string
+	OverrideBgDark   *string
+	OverrideFgDark   *string
+	OverrideLinkDark *string
+	Urgent           bool
 }

backend/internal/postgres/jet/backend/table/ad_campaigns.go

@@ -17,15 +17,22 @@ type adCampaignsTable struct {
 	postgres.Table
 
 	// Columns
-	CampaignID postgres.ColumnString
+	CampaignID       postgres.ColumnString
-	Name       postgres.ColumnString
+	Name             postgres.ColumnString
-	Weight     postgres.ColumnInteger
+	Weight           postgres.ColumnInteger
-	IsDefault  postgres.ColumnBool
+	IsDefault        postgres.ColumnBool
-	Enabled    postgres.ColumnBool
+	Enabled          postgres.ColumnBool
-	StartsAt   postgres.ColumnTimestampz
+	StartsAt         postgres.ColumnTimestampz
-	EndsAt     postgres.ColumnTimestampz
+	EndsAt           postgres.ColumnTimestampz
-	CreatedAt  postgres.ColumnTimestampz
+	CreatedAt        postgres.ColumnTimestampz
-	UpdatedAt  postgres.ColumnTimestampz
+	UpdatedAt        postgres.ColumnTimestampz
+	OverrideBg       postgres.ColumnString
+	OverrideFg       postgres.ColumnString
+	OverrideLink     postgres.ColumnString
+	OverrideBgDark   postgres.ColumnString
+	OverrideFgDark   postgres.ColumnString
+	OverrideLinkDark postgres.ColumnString
+	Urgent           postgres.ColumnBool
 
 	AllColumns     postgres.ColumnList
 	MutableColumns postgres.ColumnList
@@ -67,33 +74,47 @@ func newAdCampaignsTable(schemaName, tableName, alias string) *AdCampaignsTable
 
 func newAdCampaignsTableImpl(schemaName, tableName, alias string) adCampaignsTable {
 	var (
-		CampaignIDColumn = postgres.StringColumn("campaign_id")
+		CampaignIDColumn       = postgres.StringColumn("campaign_id")
-		NameColumn       = postgres.StringColumn("name")
+		NameColumn             = postgres.StringColumn("name")
-		WeightColumn     = postgres.IntegerColumn("weight")
+		WeightColumn           = postgres.IntegerColumn("weight")
-		IsDefaultColumn  = postgres.BoolColumn("is_default")
+		IsDefaultColumn        = postgres.BoolColumn("is_default")
-		EnabledColumn    = postgres.BoolColumn("enabled")
+		EnabledColumn          = postgres.BoolColumn("enabled")
-		StartsAtColumn   = postgres.TimestampzColumn("starts_at")
+		StartsAtColumn         = postgres.TimestampzColumn("starts_at")
-		EndsAtColumn     = postgres.TimestampzColumn("ends_at")
+		EndsAtColumn           = postgres.TimestampzColumn("ends_at")
-		CreatedAtColumn  = postgres.TimestampzColumn("created_at")
+		CreatedAtColumn        = postgres.TimestampzColumn("created_at")
-		UpdatedAtColumn  = postgres.TimestampzColumn("updated_at")
+		UpdatedAtColumn        = postgres.TimestampzColumn("updated_at")
-		allColumns       = postgres.ColumnList{CampaignIDColumn, NameColumn, WeightColumn, IsDefaultColumn, EnabledColumn, StartsAtColumn, EndsAtColumn, CreatedAtColumn, UpdatedAtColumn}
+		OverrideBgColumn       = postgres.StringColumn("override_bg")
-		mutableColumns   = postgres.ColumnList{NameColumn, WeightColumn, IsDefaultColumn, EnabledColumn, StartsAtColumn, EndsAtColumn, CreatedAtColumn, UpdatedAtColumn}
+		OverrideFgColumn       = postgres.StringColumn("override_fg")
-		defaultColumns   = postgres.ColumnList{IsDefaultColumn, EnabledColumn, CreatedAtColumn, UpdatedAtColumn}
+		OverrideLinkColumn     = postgres.StringColumn("override_link")
+		OverrideBgDarkColumn   = postgres.StringColumn("override_bg_dark")
+		OverrideFgDarkColumn   = postgres.StringColumn("override_fg_dark")
+		OverrideLinkDarkColumn = postgres.StringColumn("override_link_dark")
+		UrgentColumn           = postgres.BoolColumn("urgent")
+		allColumns             = postgres.ColumnList{CampaignIDColumn, NameColumn, WeightColumn, IsDefaultColumn, EnabledColumn, StartsAtColumn, EndsAtColumn, CreatedAtColumn, UpdatedAtColumn, OverrideBgColumn, OverrideFgColumn, OverrideLinkColumn, OverrideBgDarkColumn, OverrideFgDarkColumn, OverrideLinkDarkColumn, UrgentColumn}
+		mutableColumns         = postgres.ColumnList{NameColumn, WeightColumn, IsDefaultColumn, EnabledColumn, StartsAtColumn, EndsAtColumn, CreatedAtColumn, UpdatedAtColumn, OverrideBgColumn, OverrideFgColumn, OverrideLinkColumn, OverrideBgDarkColumn, OverrideFgDarkColumn, OverrideLinkDarkColumn, UrgentColumn}
+		defaultColumns         = postgres.ColumnList{IsDefaultColumn, EnabledColumn, CreatedAtColumn, UpdatedAtColumn, UrgentColumn}
 	)
 
 	return adCampaignsTable{
 		Table: postgres.NewTable(schemaName, tableName, alias, allColumns...),
 
 		//Columns
-		CampaignID: CampaignIDColumn,
+		CampaignID:       CampaignIDColumn,
-		Name:       NameColumn,
+		Name:             NameColumn,
-		Weight:     WeightColumn,
+		Weight:           WeightColumn,
-		IsDefault:  IsDefaultColumn,
+		IsDefault:        IsDefaultColumn,
-		Enabled:    EnabledColumn,
+		Enabled:          EnabledColumn,
-		StartsAt:   StartsAtColumn,
+		StartsAt:         StartsAtColumn,
-		EndsAt:     EndsAtColumn,
+		EndsAt:           EndsAtColumn,
-		CreatedAt:  CreatedAtColumn,
+		CreatedAt:        CreatedAtColumn,
-		UpdatedAt:  UpdatedAtColumn,
+		UpdatedAt:        UpdatedAtColumn,
+		OverrideBg:       OverrideBgColumn,
+		OverrideFg:       OverrideFgColumn,
+		OverrideLink:     OverrideLinkColumn,
+		OverrideBgDark:   OverrideBgDarkColumn,
+		OverrideFgDark:   OverrideFgDarkColumn,
+		OverrideLinkDark: OverrideLinkDarkColumn,
+		Urgent:           UrgentColumn,
 
 		AllColumns:     allColumns,
 		MutableColumns: mutableColumns,

backend/internal/postgres/migrations/00009_banner_colors_urgent.sql

@@ -0,0 +1,60 @@
+-- Per-campaign banner colour overrides and the urgent (always-show) flag.
+--
+-- ad_campaigns gains two optional colour sets and an urgent flag, all for
+-- non-default campaigns only:
+--   override_bg/fg/link           — paints the strip on every theme
+--   override_bg/fg/link_dark      — further overrides the dark theme
+--   urgent                        — force the banner on every viewer (bypassing
+--                                   eligibility) and suppress all non-urgent
+--                                   campaigns while any urgent one is active
+--
+-- Each colour set is all-or-nothing (bg+fg+link together, or absent) and every
+-- colour is a "#rrggbb" hex string. The default (house) campaign stays plain: no
+-- colours, never urgent.
+--
+-- Expand-contract: additive (nullable columns plus one NOT NULL boolean with a
+-- default), so a backend image rollback stays DB-safe — older code ignores them.
+-- The ad_campaigns table shape changes, so its generated go-jet model is
+-- regenerated (by hand here, to keep the diff to this one table).
+
+-- +goose Up
+ALTER TABLE backend.ad_campaigns
+    ADD COLUMN override_bg text,
+    ADD COLUMN override_fg text,
+    ADD COLUMN override_link text,
+    ADD COLUMN override_bg_dark text,
+    ADD COLUMN override_fg_dark text,
+    ADD COLUMN override_link_dark text,
+    ADD COLUMN urgent boolean DEFAULT false NOT NULL,
+    ADD CONSTRAINT ad_campaigns_override_all_chk CHECK (
+        (override_bg IS NULL AND override_fg IS NULL AND override_link IS NULL)
+        OR (override_bg IS NOT NULL AND override_fg IS NOT NULL AND override_link IS NOT NULL)
+    ),
+    ADD CONSTRAINT ad_campaigns_override_dark_chk CHECK (
+        (override_bg_dark IS NULL AND override_fg_dark IS NULL AND override_link_dark IS NULL)
+        OR (override_bg_dark IS NOT NULL AND override_fg_dark IS NOT NULL AND override_link_dark IS NOT NULL)
+    ),
+    ADD CONSTRAINT ad_campaigns_override_hex_chk CHECK (
+        (override_bg IS NULL OR override_bg ~ '^#[0-9a-fA-F]{6}$')
+        AND (override_fg IS NULL OR override_fg ~ '^#[0-9a-fA-F]{6}$')
+        AND (override_link IS NULL OR override_link ~ '^#[0-9a-fA-F]{6}$')
+        AND (override_bg_dark IS NULL OR override_bg_dark ~ '^#[0-9a-fA-F]{6}$')
+        AND (override_fg_dark IS NULL OR override_fg_dark ~ '^#[0-9a-fA-F]{6}$')
+        AND (override_link_dark IS NULL OR override_link_dark ~ '^#[0-9a-fA-F]{6}$')
+    ),
+    ADD CONSTRAINT ad_campaigns_default_plain_chk CHECK (
+        (NOT is_default)
+        OR (override_bg IS NULL AND override_fg IS NULL AND override_link IS NULL
+            AND override_bg_dark IS NULL AND override_fg_dark IS NULL AND override_link_dark IS NULL
+            AND NOT urgent)
+    );
+
+-- +goose Down
+ALTER TABLE backend.ad_campaigns
+    DROP COLUMN override_bg,
+    DROP COLUMN override_fg,
+    DROP COLUMN override_link,
+    DROP COLUMN override_bg_dark,
+    DROP COLUMN override_fg_dark,
+    DROP COLUMN override_link_dark,
+    DROP COLUMN urgent;

backend/internal/robot/strategyfixture_test.go

@@ -0,0 +1,146 @@
+package robot
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+
+	"scrabble/backend/internal/engine"
+)
+
+// The client-side offline robot (ui/src/lib/robot) reproduces the robot's move choice
+// so a local vs_ai game plays the same way as the server. These golden fixtures pin that
+// TS port to the real Go strategy. Being in-package, this emitter can exercise the
+// unexported mix / playToWin / deviates / selectMove that the port mirrors.
+
+type mixCase struct {
+	Seed  string `json:"seed"`
+	Salt  string `json:"salt"`
+	Nums  []int  `json:"nums"`
+	Value string `json:"value"` // the mix() uint64, as a decimal string (exceeds JS safe ints)
+}
+
+type decisionCase struct {
+	Seed       string `json:"seed"`
+	MoveCount  int    `json:"moveCount"`
+	MyScore    int    `json:"myScore"`
+	OppScore   int    `json:"oppScore"`
+	CandScores []int  `json:"candScores"`
+	RackLen    int    `json:"rackLen"`
+	BagLen     int    `json:"bagLen"`
+	PlayToWin  bool   `json:"playToWin"`
+	Win        bool   `json:"win"` // the per-turn intent after the deviate flip
+	Kind       string `json:"kind"`
+	Index      int    `json:"index"` // chosen candidate index for a play, else -1
+}
+
+type strategyFixture struct {
+	PlayToWinPercent int            `json:"playToWinPercent"`
+	Mix              []mixCase      `json:"mix"`
+	Decisions        []decisionCase `json:"decisions"`
+}
+
+// scenario is one selectMove situation exercised across several seeds.
+type scenario struct {
+	moveCount, myScore, oppScore, rackLen, bagLen int
+	cands                                         []int
+}
+
+// TestEmitStrategyFixtures regenerates ui/src/lib/robot/testdata/strategy.json. It is
+// gated by EMIT_STRATEGY_FIXTURES so a normal `go test` skips it; the committed output is
+// what the TS parity test consumes. Regenerate with:
+//
+//	EMIT_STRATEGY_FIXTURES=1 go test ./backend/internal/robot -run TestEmitStrategyFixtures
+func TestEmitStrategyFixtures(t *testing.T) {
+	if os.Getenv("EMIT_STRATEGY_FIXTURES") == "" {
+		t.Skip("set EMIT_STRATEGY_FIXTURES=1 to regenerate ui/src/lib/robot/testdata/strategy.json")
+	}
+
+	seeds := []int64{1, 42, -7, 1000003, 9999999999, 123456789, -123456789}
+
+	mixCases := []mixCase{}
+	addMix := func(seed int64, salt string, nums ...int) {
+		mixCases = append(mixCases, mixCase{
+			Seed:  strconv.FormatInt(seed, 10),
+			Salt:  salt,
+			Nums:  append([]int{}, nums...),
+			Value: strconv.FormatUint(mix(seed, salt, nums...), 10),
+		})
+	}
+	for _, sd := range seeds {
+		addMix(sd, "win")
+		addMix(sd, "deviate", 0)
+		addMix(sd, "deviate", 7)
+	}
+
+	scenarios := []scenario{
+		{3, 40, 55, 7, 20, []int{30, 12, 8}},   // behind, mid-game
+		{10, 120, 90, 7, 8, []int{25, 18, 5}},  // ahead, late
+		{1, 0, 0, 7, 30, []int{60, 30, 15, 7}}, // first move, big spread
+		{20, 200, 40, 5, 2, []int{50, 20}},     // big lead, bag near empty (no deviate)
+		{5, 30, 30, 7, 14, []int{20, 20, 20}},  // equal margins (tie-break)
+		{8, 50, 60, 7, 20, []int{}},            // no play, bag can refill -> exchange
+		{8, 50, 60, 3, 2, []int{}},             // no play, bag can't refill -> pass
+		{15, 300, 10, 7, 6, []int{80, 40, 10}}, // overshoots the band -> nearest to +30
+	}
+
+	decisions := []decisionCase{}
+	for _, sd := range seeds {
+		for _, sc := range scenarios {
+			cands := make([]engine.MoveRecord, len(sc.cands))
+			for i, s := range sc.cands {
+				cands[i] = engine.MoveRecord{Score: s, Player: i}
+			}
+			rack := make([]string, sc.rackLen)
+			for i := range rack {
+				rack[i] = "a"
+			}
+
+			ptw := playToWin(sd)
+			win := ptw
+			if deviates(sd, sc.moveCount, sc.bagLen) {
+				win = !win
+			}
+			d := selectMove(cands, sc.myScore, sc.oppScore, win, defaultBand, rack, sc.bagLen)
+
+			kind, index := "pass", -1
+			switch d.kind {
+			case decidePlay:
+				kind, index = "play", d.move.Player
+			case decideExchange:
+				kind = "exchange"
+			}
+
+			decisions = append(decisions, decisionCase{
+				Seed:       strconv.FormatInt(sd, 10),
+				MoveCount:  sc.moveCount,
+				MyScore:    sc.myScore,
+				OppScore:   sc.oppScore,
+				CandScores: append([]int{}, sc.cands...),
+				RackLen:    sc.rackLen,
+				BagLen:     sc.bagLen,
+				PlayToWin:  ptw,
+				Win:        win,
+				Kind:       kind,
+				Index:      index,
+			})
+		}
+	}
+
+	fx := strategyFixture{PlayToWinPercent: playToWinPercent, Mix: mixCases, Decisions: decisions}
+	dir := filepath.Join("..", "..", "..", "ui", "src", "lib", "robot", "testdata")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatalf("mkdir %s: %v", dir, err)
+	}
+	data, err := json.MarshalIndent(fx, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	path := filepath.Join(dir, "strategy.json")
+	if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+		t.Fatalf("write %s: %v", path, err)
+	}
+	t.Logf("wrote %s (%d mix, %d decisions)", path, len(mixCases), len(decisions))
+}

backend/internal/server/banner.go

@@ -8,6 +8,7 @@ import (
 
 	"scrabble/backend/internal/account"
 	"scrabble/backend/internal/ads"
+	"scrabble/backend/internal/engine"
 	"scrabble/backend/internal/notify"
 )
 
@@ -22,10 +23,20 @@ type bannerDTO struct {
 
 // bannerCampaignDTO is one campaign in the rotation feed: its GCD-reduced show
 // weight (for the client's smooth weighted round-robin) and its messages, in
-// display order, already resolved to one language.
+// display order, already resolved to one language. The override_* colours are
+// present only for a campaign that carries a colour override: override_bg/fg/link
+// paint every theme, and the *_dark trio further overrides the dark theme (the
+// client resolves the cascade). They are absent for a plain campaign, which keeps
+// the neutral theme tokens.
 type bannerCampaignDTO struct {
-	Weight   int      `json:"weight"`
+	Weight           int      `json:"weight"`
-	Messages []string `json:"messages"`
+	Messages         []string `json:"messages"`
+	OverrideBg       string   `json:"override_bg,omitempty"`
+	OverrideFg       string   `json:"override_fg,omitempty"`
+	OverrideLink     string   `json:"override_link,omitempty"`
+	OverrideBgDark   string   `json:"override_bg_dark,omitempty"`
+	OverrideFgDark   string   `json:"override_fg_dark,omitempty"`
+	OverrideLinkDark string   `json:"override_link_dark,omitempty"`
 }
 
 // bannerTimingsDTO mirrors ads.Timings on the wire.
@@ -46,9 +57,34 @@ func (s *Server) profileResponse(ctx context.Context, acc account.Account) profi
 	r := profileResponseFor(acc)
 	r.Banner = s.bannerFor(ctx, acc)
 	s.fillLinkedIdentities(ctx, &r, acc.ID)
+	r.DictVersions = s.currentDictVersions()
 	return r
 }
 
+// currentDictVersions reports the current dictionary version of every game variant with a
+// resident dictionary, as engine.Variant stable labels. It backs profileResponse.DictVersions
+// so an offline-capable client preloads the matching dawg per variant off the cold-start
+// profile. A variant without a loaded dictionary is omitted (Registry.Latest reports
+// ErrUnknownVariant); the returned slice is nil only when no variant is resident.
+func (s *Server) currentDictVersions() []dictVersion {
+	if s.registry == nil {
+		return nil // no dictionary registry wired (e.g. a minimal test server): advertise none
+	}
+	variants := []engine.Variant{engine.VariantEnglish, engine.VariantRussianScrabble, engine.VariantErudit}
+	out := make([]dictVersion, 0, len(variants))
+	for _, v := range variants {
+		version, _, err := s.registry.Latest(v)
+		if err != nil {
+			continue
+		}
+		out = append(out, dictVersion{Variant: v.String(), Version: version})
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}
+
 // fillLinkedIdentities sets the profile's confirmed email address and platform-linked
 // flags from the account's identities, so the client offers the right link / unlink /
 // change-email controls. A read failure leaves them zero (no controls), logged as a
@@ -83,22 +119,27 @@ func (s *Server) bannerFor(ctx context.Context, acc account.Account) *bannerDTO
 	if s.ads == nil {
 		return nil
 	}
-	hasNoBanner, err := s.accounts.HasRole(ctx, acc.ID, account.RoleNoBanner)
+	set, timings, urgent, err := s.ads.ActiveSet(ctx, bannerLang(acc))
-	if err != nil {
-		s.log.Warn("banner: role check failed", zap.String("account", acc.ID.String()), zap.Error(err))
-		return nil
-	}
-	if !ads.Eligible(acc.PaidAccount, acc.HintBalance, hasNoBanner) {
-		return nil
-	}
-	set, timings, err := s.ads.ActiveSet(ctx, bannerLang(acc))
 	if err != nil {
 		s.log.Warn("banner: active set failed", zap.String("account", acc.ID.String()), zap.Error(err))
 		return nil
 	}
+	// An urgent campaign is shown to every viewer; otherwise the normal eligibility
+	// gate applies (a paid account, a non-empty hint wallet or the no_banner role
+	// hides the banner).
+	if !urgent {
+		hasNoBanner, err := s.accounts.HasRole(ctx, acc.ID, account.RoleNoBanner)
+		if err != nil {
+			s.log.Warn("banner: role check failed", zap.String("account", acc.ID.String()), zap.Error(err))
+			return nil
+		}
+		if !ads.Eligible(acc.PaidAccount, acc.HintBalance, hasNoBanner) {
+			return nil
+		}
+	}
 	campaigns := make([]bannerCampaignDTO, 0, len(set))
 	for _, c := range set {
-		campaigns = append(campaigns, bannerCampaignDTO{Weight: c.Weight, Messages: c.Messages})
+		campaigns = append(campaigns, bannerCampaignFromActive(c))
 	}
 	return &bannerDTO{
 		Campaigns: campaigns,
@@ -113,6 +154,20 @@ func (s *Server) bannerFor(ctx context.Context, acc account.Account) *bannerDTO
 	}
 }
 
+// bannerCampaignFromActive flattens a resolved campaign into its wire DTO,
+// projecting each optional colour set into its three "#rrggbb" fields (empty when
+// the set is absent, so JSON omitempty drops them).
+func bannerCampaignFromActive(c ads.ActiveCampaign) bannerCampaignDTO {
+	d := bannerCampaignDTO{Weight: c.Weight, Messages: c.Messages}
+	if c.OverrideAll != nil {
+		d.OverrideBg, d.OverrideFg, d.OverrideLink = c.OverrideAll.Bg, c.OverrideAll.Fg, c.OverrideAll.Link
+	}
+	if c.OverrideDark != nil {
+		d.OverrideBgDark, d.OverrideFgDark, d.OverrideLinkDark = c.OverrideDark.Bg, c.OverrideDark.Fg, c.OverrideDark.Link
+	}
+	return d
+}
+
 // bannerLang resolves the message language for a viewer: their interface language
 // (Russian, or English by default).
 func bannerLang(acc account.Account) string {

backend/internal/server/dto.go

@@ -63,6 +63,20 @@ type profileResponse struct {
 	Email          string `json:"email"`
 	TelegramLinked bool   `json:"telegram_linked"`
 	VkLinked       bool   `json:"vk_linked"`
+	// DictVersions lists the current dictionary version per game variant (engine.Variant
+	// stable labels). An installed PWA preparing for offline play reads it to preload the
+	// right dawg per enabled variant off this cold-start response, without an extra request.
+	// Filled outside the pure projection (it reads the dictionary registry), so it is empty
+	// for callers that build the DTO without a Server. See Server.profileResponse.
+	DictVersions []dictVersion `json:"dict_versions,omitempty"`
+}
+
+// dictVersion pairs a game variant's stable label (engine.Variant.String) with its current
+// dictionary version. profileResponse.DictVersions carries the set so an offline-capable
+// client preloads the matching dawg per variant.
+type dictVersion struct {
+	Variant string `json:"variant"`
+	Version string `json:"version"`
 }
 
 // tileDTO is one placed (or to-place) tile.
@@ -149,13 +163,16 @@ type alphabetEntryDTO struct {
 // stateDTO is a player's view of a game. Rack carries wire alphabet indices (a
 // blank is engine.BlankIndex). Alphabet is present only when the request asked for it.
 type stateDTO struct {
-	Game           gameDTO            `json:"game"`
+	Game           gameDTO `json:"game"`
-	Seat           int                `json:"seat"`
+	Seat           int     `json:"seat"`
-	Rack           []int              `json:"rack"`
+	Rack           []int   `json:"rack"`
-	BagLen         int                `json:"bag_len"`
+	BagLen         int     `json:"bag_len"`
-	HintsRemaining int                `json:"hints_remaining"`
+	HintsRemaining int     `json:"hints_remaining"`
-	WalletBalance  int                `json:"wallet_balance"`
+	WalletBalance  int     `json:"wallet_balance"`
-	Alphabet       []alphabetEntryDTO `json:"alphabet,omitempty"`
+	// HintUnlockLeftSeconds is the vs_ai idle-hint gate: seconds until the hint unlocks (0 for a human
+	// game / first move / not your turn). The client anchors a monotonic countdown to it.
+	HintUnlockLeftSeconds int                `json:"hint_unlock_left_seconds"`
+	Alphabet              []alphabetEntryDTO `json:"alphabet,omitempty"`
 }
 
 // matchDTO reports whether the caller has been paired into a game.
@@ -301,12 +318,13 @@ func stateDTOFrom(v game.StateView, includeAlphabet bool) (stateDTO, error) {
 		return stateDTO{}, err
 	}
 	dto := stateDTO{
-		Game:           gameDTOFromGame(v.Game),
+		Game:                  gameDTOFromGame(v.Game),
-		Seat:           v.Seat,
+		Seat:                  v.Seat,
-		Rack:           rack,
+		Rack:                  rack,
-		BagLen:         v.BagLen,
+		BagLen:                v.BagLen,
-		HintsRemaining: v.HintsRemaining,
+		HintsRemaining:        v.HintsRemaining,
-		WalletBalance:  v.WalletBalance,
+		WalletBalance:         v.WalletBalance,
+		HintUnlockLeftSeconds: v.HintUnlockLeftSeconds,
 	}
 	if includeAlphabet {
 		tab, err := engine.AlphabetTable(v.Game.Variant)

backend/internal/server/handlers.go

@@ -239,6 +239,9 @@ func statusForError(err error) (int, string) {
 		return http.StatusConflict, "no_hint_available"
 	case errors.Is(err, game.ErrHintsDisabled), errors.Is(err, game.ErrNoHintsLeft):
 		return http.StatusConflict, "hint_unavailable"
+	case errors.Is(err, game.ErrHintLocked):
+		// A vs_ai idle hint is still gated (the server-clock backstop); the client shows the lock.
+		return http.StatusConflict, "hint_locked"
 	case errors.Is(err, engine.ErrIllegalPlay), errors.Is(err, engine.ErrTilesNotOnRack), errors.Is(err, engine.ErrGameOver):
 		return http.StatusUnprocessableEntity, "illegal_play"
 	case errors.Is(err, account.ErrEmailTaken), errors.Is(err, account.ErrIdentityTaken):

backend/internal/server/handlers_admin_banners.go

@@ -19,6 +19,15 @@ const bannersBack = "/_gm/banners"
 // bound; the operator's entry is interpreted as UTC.
 const localTimeLayout = "2006-01-02T15:04"
 
+// Neutral banner theme tokens, mirrored from ui/src/app.css (--ad-bg,
+// --text-muted, --accent for the light and dark themes). They seed the console's
+// colour pickers and the preview fallback when a campaign has no override, so the
+// operator always edits against the real neutral colours.
+const (
+	tokenLightBg, tokenLightFg, tokenLightLink = "#e3e7ee", "#6b7280", "#2f6df6"
+	tokenDarkBg, tokenDarkFg, tokenDarkLink    = "#272f3c", "#9aa3b2", "#5b8cff"
+)
+
 // consoleBanners lists the advertising campaigns (default first), each with its
 // weight, validity window, enabled flag, message count and live-now status.
 func (s *Server) consoleBanners(c *gin.Context) {
@@ -56,14 +65,19 @@ func (s *Server) consoleBannerDetail(c *gin.Context) {
 		return
 	}
 	view := adminconsole.BannerDetailView{
-		ID:        cm.ID.String(),
+		ID:             cm.ID.String(),
-		Name:      cm.Name,
+		Name:           cm.Name,
-		Weight:    cm.Weight,
+		Weight:         cm.Weight,
-		IsDefault: cm.IsDefault,
+		IsDefault:      cm.IsDefault,
-		Enabled:   cm.Enabled,
+		Enabled:        cm.Enabled,
-		StartsAt:  localInput(cm.StartsAt),
+		StartsAt:       localInput(cm.StartsAt),
-		EndsAt:    localInput(cm.EndsAt),
+		EndsAt:         localInput(cm.EndsAt),
+		Urgent:         cm.Urgent,
+		OverrideAllOn:  cm.OverrideAll != nil,
+		OverrideDarkOn: cm.OverrideDark != nil,
 	}
+	view.AllBg, view.AllFg, view.AllLink = seedColors(cm.OverrideAll, tokenLightBg, tokenLightFg, tokenLightLink)
+	view.DarkBg, view.DarkFg, view.DarkLink = seedColors(cm.OverrideDark, tokenDarkBg, tokenDarkFg, tokenDarkLink)
 	for i, m := range cm.Messages {
 		view.Messages = append(view.Messages, adminconsole.BannerMessageRow{
 			ID:     m.ID.String(),
@@ -111,12 +125,15 @@ func (s *Server) consoleUpdateBanner(c *gin.Context) {
 		return
 	}
 	err = s.ads.UpdateCampaign(c.Request.Context(), ads.Campaign{
-		ID:       id,
+		ID:           id,
-		Name:     trimForm(c, "name"),
+		Name:         trimForm(c, "name"),
-		Weight:   atoiForm(c, "weight"),
+		Weight:       atoiForm(c, "weight"),
-		Enabled:  c.PostForm("enabled") != "",
+		Enabled:      c.PostForm("enabled") != "",
-		StartsAt: starts,
+		StartsAt:     starts,
-		EndsAt:   ends,
+		EndsAt:       ends,
+		Urgent:       c.PostForm("urgent") != "",
+		OverrideAll:  colorSetForm(c, "override_all_on", "override_bg", "override_fg", "override_link"),
+		OverrideDark: colorSetForm(c, "override_dark_on", "override_bg_dark", "override_fg_dark", "override_link_dark"),
 	})
 	if err != nil {
 		s.bannerError(c, err, back)
@@ -321,3 +338,29 @@ func atoiForm(c *gin.Context, name string) int {
 	n, _ := strconv.Atoi(trimForm(c, name))
 	return n
 }
+
+// seedColors returns the three colour-input seed values for a campaign's optional
+// override: the stored colours when the set is present, otherwise the given
+// neutral theme tokens (so the native picker starts sensibly and the preview
+// shows the real fallback).
+func seedColors(cs *ads.ColorSet, tokenBg, tokenFg, tokenLink string) (bg, fg, link string) {
+	if cs == nil {
+		return tokenBg, tokenFg, tokenLink
+	}
+	return cs.Bg, cs.Fg, cs.Link
+}
+
+// colorSetForm reads an optional colour override from the form: the on flag gates
+// it (an unchecked set is absent, nil), otherwise the three posted colours are
+// returned for the ads service to validate. The colour inputs are disabled in the
+// browser while the set is off, so they are not posted then.
+func colorSetForm(c *gin.Context, on, bg, fg, link string) *ads.ColorSet {
+	if c.PostForm(on) == "" {
+		return nil
+	}
+	return &ads.ColorSet{
+		Bg:   trimForm(c, bg),
+		Fg:   trimForm(c, fg),
+		Link: trimForm(c, link),
+	}
+}

backend/internal/server/handlers_auth.go

@@ -174,6 +174,10 @@ type emailRequest struct {
 	Email     string `json:"email"`
 	BrowserTZ string `json:"browser_tz"`
 	Language  string `json:"language"`
+	// Pwa marks a request from an installed PWA (standalone display mode): the login email then
+	// omits the one-tap confirm link so the code is typed in the same window (the link would open
+	// in a separate browser whose session cannot reach the PWA). See EmailService.RequestLoginCode.
+	Pwa bool `json:"pwa"`
 }
 
 // handleEmailRequest issues a login confirm-code to the email. It always reports
@@ -185,7 +189,7 @@ func (s *Server) handleEmailRequest(c *gin.Context) {
 		abortBadRequest(c, "email is required")
 		return
 	}
-	if _, err := s.emails.RequestLoginCode(c.Request.Context(), req.Email, req.BrowserTZ, req.Language); err != nil {
+	if _, err := s.emails.RequestLoginCode(c.Request.Context(), req.Email, req.BrowserTZ, req.Language, req.Pwa); err != nil {
 		s.abortErr(c, err)
 		return
 	}

docs/ARCHITECTURE.md

@@ -244,7 +244,9 @@ arrive from a platform rather than completing a mandatory registration).
   256-bit token stored only as its SHA-256, 12-hour TTL): a login mints a session in the
   browser that opens it (magic-link), a link confirms the identity and emits a `notify`
   profile-refresh to the in-app session, a change switches the account's email in place,
-  and a would-be merge is deferred to the interactive flow. The confirm runs on load; the token rides the URL fragment (never
+  and a would-be merge is deferred to the interactive flow. A login requested from an installed **PWA** omits the deeplink
+  entirely — its email carries the code only, typed in the same window, since the link would open
+  in a separate browser whose minted session cannot reach the PWA. The confirm runs on load; the token rides the URL fragment (never
   sent to the server), so a plain link prefetch cannot reach it, and the manual
   six-digit code is the fallback if an aggressive scanner runs the page. An
   **email-login** account is created flagged `is_guest` and stays reapable until the
@@ -980,10 +982,25 @@ edge-pause, scroll speed, and the fade-out → gap → fade-in transition) are o
 eligibility inputs (grants hints, grants/revokes `no_banner`; a future payment flow sets
 `paid_account`), the backend emits a `notify` **`banner`** sub-kind (a payload-free re-poll signal),
 and the open client re-fetches `profile.get` to show or hide the banner in place. Operator *content*
-edits take effect on the next `profile.get` (open/reconnect/foreground), not mid-session. The same
+edits take effect on the next `profile.get` (open/reconnect/foreground), not mid-session. A
+non-default campaign may also carry an optional **colour override** (background, text, link) in two
+sets — one for every theme, one for the dark theme only — plus an **urgent** flag. The colours ride
+the same block (six optional strings appended to each `BannerCampaign` on the wire — trailing,
+backward-compatible); the client resolves the cascade (dark ← dark ?? all, light ← all) and derives
+the strip's border from the background in JS (no CSS `color-mix`, for the old-WebView floor).
+**Urgent is resolved entirely server-side, with no wire field**: while any enabled, in-window urgent
+campaign exists, `computeActiveSet` returns *only* the urgent campaigns (preempting the timed set and
+the default remainder) and `bannerFor` **skips the eligibility gate** for that feed, so an urgent
+notice reaches every viewer — paid, hint-holding or `no_banner` included. There is no instant
+broadcast on an urgent toggle (the notify path is per-user); an urgent campaign appears on each
+viewer's next `profile.get`. The default campaign stays plain (no colours, never urgent), enforced by
+both the service and a DB CHECK. The same
 mechanism carries a **`profile`** sub-kind — a payload-free re-fetch signal emitted when a viewer's
 own account changed out of band (an email confirmed through the one-tap deeplink opened in another
-browser), so an open in-app session reflects it at once.
+browser), so an open in-app session reflects it at once. The live stream is single-shot with no
+replay, so a **backgrounded Mini App** — suspended while the user is in their mail app tapping the
+link — misses the event; while an add-email confirmation is pending the client therefore also
+**polls `profile.get`** (and on foreground regain) as a fallback until the address lands.
 
 > A single `app.load` bootstrap aggregator (collapsing `profile.get` + lobby + badge fetches into
 > one round-trip) was **considered and deferred**: client↔gateway is HTTP/2 (h2c), so the bootstrap
@@ -1026,7 +1043,9 @@ browser), so an open in-app session reflects it at once.
   (`internal/adminalert`, started from `main`) emails the operator (`ADMIN_EMAIL`, from a
   distinct `SMTP_RELAY_ADMIN_FROM`) when new player feedback or word complaints arrive,
   **coalescing** a burst into one digest per interval; both recipients may be several
-  comma-separated addresses. Both paths are inert unless configured.
+  comma-separated addresses. The digest carries **no admin-console link** — an admin URL must
+  never travel in an email, where a mail provider could cache or index it; the operator opens the
+  console directly. Both paths are inert unless configured.
 - Per-request server-side timing via gin middleware from day one (the access log
   carries method, route, status, latency and the active trace id). A
   client-measured RTT piggybacked on the next request is a later enhancement.
@@ -1218,7 +1237,76 @@ origin, so the test contour canonicalises to production instead of being indexed
 separate site; the SPA shell is `noindex`, and the landing always boots in Russian (no
 browser-language detection — crawlers render with arbitrary languages). The favicon set,
 `og-image.png` and `robots.txt` ship unhashed from `ui/public/` (generated by
-`assets/icons/`, same tile design as the VK loader). Hash-named `/assets/*` are served
+`assets/icons/`, same tile design as the VK loader). On the web (`/app/`) the SPA is an installable **PWA**:
+`manifest.webmanifest` ships unhashed from `ui/public/`, while the **service worker** (`sw.js`) is
+built from `ui/src/sw.ts` by **vite-plugin-pwa** (injectManifest strategy) — the client registers it
+**web-only**, never inside a Mini App or the mock build (the plugin is disabled there entirely). It
+**precaches the app shell and the hashed assets** (Workbox) so an installed PWA cold-launches with
+no network. Shell **navigations are network-first** — the fresh `no-cache` shell is fetched from the
+server (so a new deploy is picked up on the very next launch, not the one after), falling back to the
+precached shell only when the network is unreachable or too slow; the immutable hashed assets stay
+cache-first, and the hash router resolves the route client-side. This navigation route is registered
+**before** the precache route on purpose: Workbox matches in registration order, and the precache
+route (its `directoryIndex` is `index.html`) would otherwise shadow it and serve the shell
+cache-first — the old build's version until a second load. The landing page and the conditional
+polyfill bundle are excluded, and the Connect stream and runtime API POSTs are never precached nor
+intercepted, so the live app is never served stale. This satisfies Chromium's installability requirement (a registered SW, needed
+for install on Android) and powers the opt-in **offline mode** (in progress): a deliberate, device-scoped Settings
+toggle — distinct from the transient gateway-reachability signal — that tints the header blue with
+an *Offline* chip and confines play to on-device `vs_ai` games. The **offline lobby lists only those
+device-local games** (reconstructed by replaying the IndexedDB move journal) and its New-vs-AI entry
+creates one through the in-browser engine — the same game screen then drives it, the robot replying
+locally; online-only affordances (the Stats tab, the random-opponent option) are disabled
+or hidden, and New Game's *with friends* becomes the entry to **local pass-and-play (hotseat)**.
+A hotseat game is a device-local **2-4 human** game built through the same engine (`hotseat` +
+per-seat/host PIN locks on the record; the seats carry names but no accounts). A **mandatory host
+(referee) PIN** gates the roster at creation and, in-game, the referee overrides — **skip** the
+current turn, **exclude** a player (a forced seat resign, `resignSeat`) or **terminate** the game
+(deleted, no winner/loser); each seat may also carry its own **optional PIN** that withholds its rack
+(the board stays visible — only the tray is gated) until it is entered, so players pass the device
+around freely and lock a seat only against a distrusted tablemate. The unlock is **per turn**
+(re-locks on advance). PINs are a **social lock, not cryptography** — a salted SHA-256 kept only in
+the device record (`lib/pin`); a 4-digit PIN is trivially brute-forceable and the racks live in
+client memory regardless, so they defeat a casual glance, not a determined peek. A hotseat game is
+**not `vs_ai`**: hints (the freed control becomes the host button) and chat/self-resign are gone, and
+its lobby card — active *and* finished — is master-PIN-gated to delete (so the last mover cannot
+instantly wipe it); a naturally finished game is saved with its result like any local game. A `vs_ai`
+hint (online and offline alike) is unlimited and wallet-free but idle-gated
+(unlocked ~30 min into a stuck turn), and counts toward no hint statistic. The **source** reports the
+**seconds left** (`hint_unlock_left_seconds` on the game view) — computed by the **backend from the
+server clock** online (which also enforces the gate, returning `hint_locked` for an early request),
+and by the offline source from the device clock (persisted, capped at the window). The **client
+anchors a MONOTONIC countdown** (`performance.now()`, `lib/hints`) to that seconds-left when it lands
+(on load, and to the full window when the robot moves), so a client clock change cannot skew it, and
+a relaunch re-reads a fresh value so the wait is not forgotten. To have data ready before the switch, the **Profile advertises the current dictionary
+version per variant** (`dict_versions`,
+filled from the registry on the existing cold-start profile request — no extra round-trip), and an
+eligible installed PWA (standalone web + confirmed email) **background-preloads** those dictionaries
+— on lobby entry and on a variant-preference change — through the same three-tier loader, retried
+with backoff and honouring the session miss-breaker; the move generator, the loader and the preload
+orchestration stay in lazy chunks. A first-lobby preload failure shows a *poor-connection* notice in
+the ad-banner slot. Flipping the Settings toggle **to** offline runs that same cache-first fetch
+bounded by a ~5 s UI wait (`raceOfflineReady` + the lazy `dict/offlineready`): it enters offline only
+once every enabled variant is ready, otherwise it stays online with a *needs internet* note while the
+fetch finishes in the background (the next flip is then instant). A **cold launch already in offline
+mode** boots from the persisted session and
+profile (the profile is saved on every online adopt/refresh) — `bootstrap` skips the session
+adoption and profile fetch that would otherwise hang with no network, and lands straight in the
+offline lobby; without a cached profile (an install that was never online) it drops the sticky flag
+and boots online instead. Beyond the sticky toggle the app **auto-detects connectivity**: the
+reactive flag carries an *auto* bit, so a self-entered offline (no network) is transient
+(session-only, never persisted) and self-heals to online when the network returns, while a deliberate
+one (the toggle, or the cold-start dialog's *Switch*) persists. At cold start `navigator.onLine ===
+false` enters offline for the session; otherwise a single bounded reachability probe (a `profile.get`,
+~3 s) decides — success boots online, a timeout on an eligible install raises a *No connection* dialog
+(*Switch* = sticky offline, *Wait for network* = boot online with the reachability watcher retrying).
+Mid-session the `window` `online`/`offline` events drive it — `offline` auto-enters, `online`
+re-verifies reachability before returning — backed by a `navigator.onLine` poll because those events
+are unreliable on some platforms (notably iOS PWAs). Offline is a real **transport kill switch**
+(every gateway call is refused, so no traffic leaks); the reachability probe is the one call exempt
+from it (it is the return-to-online mechanism), and the transient reachability watcher is suppressed
+while offline. The gateway registers the `.webmanifest` MIME type
+in-process (the distroless image has no `/etc/mime.types`). Hash-named `/assets/*` are served
 `immutable` (a relaunch is a cache hit, not a re-download); the HTML shells are
 `no-cache` so a new deploy is picked up — both containers apply the same caching. An
 in-compose **caddy** is the contour's edge: it owns a single `/_gm` Basic-Auth and

docs/FUNCTIONAL.md

@@ -21,7 +21,8 @@ Settings also pick the board's bonus-label style (beginner / classic / none). A
 costs nothing when the rack has no legal move. The word-check accepts only the
 variant's alphabet, remembers answers within the session and rate-limits repeats.
 A public **landing page** at the site root introduces the game, switches language and
-theme, and links to the Telegram game channel and the VK Mini App; the game itself runs at
+theme, and links to the Telegram game channel, the VK Mini App and the **web version**
+(`/app/`) — each under a caption (Telegram / VK / Веб-версия); the game itself runs at
 `/app/` (web), `/telegram/` (the Telegram Mini App) and `/vk/` (the VK Mini App). The landing's theme is ephemeral
 (it follows the system scheme, not the saved preference); its language choice is saved. The
 landing always opens in **Russian** — the browser language is never auto-detected (crawlers
@@ -31,6 +32,11 @@ nondeterministic); a saved 🌐 choice still wins. The page carries a static Rus
 pinned to the production origin, JSON-LD, the favicon set and `robots.txt`), while the SPA
 shell is `noindex` — the landing is the only indexable page.
 
+On the plain web the client is an **installable PWA**: a logged-out player sees an install
+call-to-action under the login form (and at the bottom of Settings) that installs the app to the
+home screen / desktop in one tap where the browser supports it (Chromium), or shows manual
+Add-to-Home-Screen steps on iOS Safari; it is hidden once installed and inside the Mini Apps.
+
 ### First-run onboarding
 The first time a player opens the app it walks them through the interface with a light
 **coachmark overlay**: a dimmed layer draws one hint bubble at a time, each pointing — with a
@@ -70,7 +76,9 @@ per address), so a mistyped address or an impatient tap cannot flood an inbox. T
 also carries a **one-tap link** that confirms the address — or signs the player straight
 in — in a single tap; opening it in another browser reflects in the app at once, and a
 mail scanner that merely fetches the link cannot reach it — the token rides the URL
-fragment, which is never sent to the server.
+fragment, which is never sent to the server. A sign-in requested from an **installed PWA** omits
+this link: the email carries only the code, entered in the same window, since the link would open
+in a separate browser the app cannot reach.
 Telegram runs a **single bot**: every player uses
 the same bot, and all of its chat and out-of-app notifications are written in the
 player's own **interface language** (en/ru). A separate optional **promo bot** can run alongside the
@@ -109,7 +117,9 @@ two accounts share a game still in progress.
 
 The profile lists the account's **sign-in methods**. On the web a player can add
 Telegram (a login-widget popup) or VK (VK ID web login — a redirect to VK's sign-in and
-back); inside a Mini App the host platform is already linked. Linking a provider that
+back); inside a Mini App the host platform is already linked, and its own sign-in-method
+row is hidden — the platform the player is currently signed in through cannot be unlinked
+from there, only the other provider's row is shown. Linking a provider that
 already belongs to another account offers the same irreversible **merge** as email
 linking. A linked provider can be **unlinked** — except the last
 remaining sign-in method, which is refused so the account stays reachable. **Email is
@@ -205,7 +215,16 @@ unlimited and offers a complaint on any result; for a word it finds, it also lin
 external reference dictionary (gramota.ru for Russian games, scrabblewordfinder.org for
 English) to look it up. Hints are governed per game —
 whether they are allowed and how many each player starts with — and draw on a
-personal hint wallet once the per-game allowance is spent. The game ends when the
+personal hint wallet once the per-game allowance is spent. Against the robot
+(**vs_ai**) hints are instead **unlimited and wallet-free**, but idle-gated as an
+anti-frustration aid: one unlocks only after the player has been **stuck ~30 minutes
+on a turn** (timed from the robot's last move; the very first move, before the robot
+has played, is exempt). While gated the hint button carries a small **🔒 lock** and a
+tap shows how long remains; the lock lifts live at the mark. The same gate applies **online and
+offline**: the countdown runs on a **steady in-app timer**, not the device clock, so changing the
+clock cannot skew it, and a relaunch re-reads the remaining time so a stuck turn is not forgotten.
+Online the **server enforces** it from its own clock (which the player cannot touch); a vs_ai hint
+counts toward no hint statistic. The game ends when the
 bag empties and a player clears their rack, after 6 consecutive scoreless turns,
 by resignation, or by the per-game move timeout (5 minutes to 24 hours, default
 24 hours): a missed turn auto-resigns, except while the player is inside their
@@ -246,6 +265,44 @@ the same occasional move against its plan that fades out by the endgame), and ch
 add-friend are off. AI games are **practice** — they never count toward a player's
 statistics.
 
+### Offline mode
+An installed web PWA signed in with a confirmed email can switch to a deliberate **offline mode**
+(Settings → Play mode). Offline, the app never touches the network: the header turns blue with an
+*Offline* chip, the lobby lists only the games stored on the device, and online-only surfaces are
+disabled or hidden (the Stats tab; the *random opponent* option in New Game).
+A New Game against the robot creates a device-local **vs_ai** game — it
+plays entirely in the browser with no backend. Local games are kept on the device, visible only in
+offline mode, and never sync to the account. So a game can be created and played with no connection,
+the app quietly preloads the dictionaries for the player's enabled variants while still online, and
+(once installed) launches from a precached shell even with no network. Switching **to** offline first
+checks that the enabled variants' dictionaries are on the device — if any are missing it fetches them
+and waits briefly, and if they cannot be readied it stays online with a short *needs internet* note
+(the download keeps running in the background, so a later switch is instant). The mode is
+device-scoped and sticky across launches.
+
+Offline, New Game's **with friends** starts a **local pass-and-play** game for 2-4 people sharing one
+device. You first set a **host (leader) password** — a 4-digit PIN entered on a lock-screen-style
+keypad; until it is set the player rows stay locked. The app then asks whether you are playing too —
+if so you take the first seat with your profile name. You name each player (2 to 4; add or remove
+rows, where a removal asks for the leader password) and may give any seat its **own optional PIN**.
+During the game the board is always visible, but a PIN-locked seat shows an **Unlock** button in place
+of its rack until its owner enters the PIN — so the device passes hand to hand and only a protected
+seat hides its letters; the lock returns each turn. The **leader** (the host button in the game) can,
+with the leader password, **skip** the current player's turn, **remove** a player, or **end the game
+early** — an early end discards the game with no winner or loser. Hints and chat are off in a
+pass-and-play game. A game that finishes normally is saved to the offline lobby like any other;
+deleting any pass-and-play game — running or finished — from the lobby asks for the leader password,
+so no one can wipe a game the moment they have moved.
+
+The app also **enters offline mode on its own** when it cannot reach the network. On a cold launch
+with no connection it switches to offline for that session; when the device is online but the gateway
+stays silent for a few seconds it asks first — *No connection. Switch to offline mode?*, with
+**Switch** (go offline) or **Wait for network** (keep retrying online). While the app is open, losing
+the network — airplane mode — switches to offline automatically, and restoring it returns online by
+itself. A self-entered offline is temporary: it reverts to online the moment the network is back, and
+the next launch re-checks. A **deliberate** offline — the Settings toggle, or **Switch** in that
+dialog — is the player's choice: it is kept, and never undone automatically.
+
 ### Social: friends, block, chat, nudge
 Become friends in two ways: redeem a **one-time code** the other player issues (six
 digits, valid for twelve hours), or send a **request to someone you have played
@@ -483,8 +540,19 @@ through**, regardless of their interface language. The client rotates the eligib
 **fairly** — every campaign gets its weighted share each cycle, evenly spread rather than at random —
 and a campaign with several messages shows them in turn.
 
+A non-default campaign can carry its own **colours** — background, text and link — so a sponsored or
+operational message stands out from the neutral strip. Colours come in two sets: one that applies on
+**every theme**, and an optional second that overrides the **dark theme** only, so a campaign reads
+well on both; the strip's border is derived from the background automatically. A campaign can also be
+marked **urgent**: an urgent campaign is shown to **everyone** — even paid players, hint holders and
+`no_banner` users — and, while it is live, it is the **only** thing the strip shows (ordinary
+campaigns and the house default step aside). Urgent is for genuine system notices (maintenance,
+outages), not advertising.
+
 Operators manage all of this in the admin console at **`/_gm/banners`**: create, edit, enable/disable
-and schedule campaigns, write each campaign's bilingual messages (reorder or remove them), and set
+and schedule campaigns, write each campaign's bilingual messages (reorder or remove them), pick a
-the global display **timings** (how long a message holds, the scroll of an over-long message, and the
+non-default campaign's optional override colours (a native colour picker with a live light-and-dark
-fade-out → gap → fade-in transition between messages). The default campaign cannot be deleted and
+preview of the strip) and mark it urgent, and set the global display **timings** (how long a message
-keeps at least one message.
+holds, the scroll of an over-long message, and the fade-out → gap → fade-in transition between
+messages). The default campaign cannot be deleted, keeps at least one message, and stays plain (no
+colours, never urgent).

docs/FUNCTIONAL_ru.md

@@ -22,7 +22,8 @@ top-1 подсказку, безлимитную проверку слова с
 Проверка слова принимает только алфавит варианта, запоминает ответы в рамках сессии
 и ограничивает частоту повторов.
 Публичная **посадочная страница** в корне сайта представляет игру, переключает язык и
-тему и ведёт в Telegram-канал игры и в VK Mini App; сама игра живёт по адресам
+тему и ведёт в Telegram-канал игры, в VK Mini App и в **веб-версию** (`/app/`) — каждая под
+подписью (Telegram / VK / Веб-версия); сама игра живёт по адресам
 `/app/` (веб), `/telegram/` (Telegram Mini App) и `/vk/` (VK Mini App). Тема на странице эфемерна (берётся из
 системной настройки, а не из сохранённой), выбор языка сохраняется. Страница всегда
 открывается на **русском** — язык браузера не определяется автоматически (роботы
@@ -33,6 +34,11 @@ Open Graph, которую используют превью ссылок в Tel
 продакшен-домена, JSON-LD, набор favicon и `robots.txt`), а оболочка SPA помечена
 `noindex` — индексируется только посадочная страница.
 
+В обычном вебе клиент — **устанавливаемое PWA**: незалогиненный игрок видит призыв к установке
+под формой входа (и внизу «Настроек»), который в один тап ставит приложение на рабочий стол
+(домашний экран) там, где браузер это умеет (Chromium), либо показывает ручные шаги
+«На экран „Домой“» в Safari на iOS; он скрыт после установки и внутри Mini App.
+
 ### Первый запуск: онбординг
 При первом открытии приложения игрока один раз проводят по интерфейсу лёгким
 **coachmark-оверлеем**: затемнённый слой показывает по одной подсказке-«облачку» за раз, каждое
@@ -74,7 +80,9 @@ launch-параметрам VK (их проверяет gateway), и при пе
 не завалили почтовый ящик. В письме также есть **ссылка одного нажатия**, которая подтверждает
 адрес — или сразу выполняет вход — в один тап; открытие её в другом браузере тут же отражается в
 приложении, а почтовый сканер, который просто загружает ссылку, до токена не дотянется —
-он едет в URL-фрагменте, который не уходит на сервер.
+он едет в URL-фрагменте, который не уходит на сервер. Вход, запрошенный из **установленного
+PWA**, эту ссылку не содержит: в письме только код, который вводится в том же окне (ссылка
+открылась бы в отдельном браузере, недоступном приложению).
 Telegram держит **единого бота**: все игроки пользуются одним
 и тем же ботом, а весь его чат и внеприложенческие уведомления пишутся на **языке
 интерфейса** самого игрока (en/ru). Рядом с основным может работать отдельный опциональный
@@ -113,7 +121,9 @@ Telegram держит **единого бота**: все игроки поль
 
 В профиле перечислены **способы входа** аккаунта. В вебе игрок может добавить
 Telegram (попап логин-виджета) или VK (веб-вход VK ID — редирект на страницу входа VK и
-обратно); внутри Mini App платформа-хозяин уже привязана. Привязка провайдера, уже
+обратно); внутри Mini App платформа-хозяин уже привязана, и её собственная плашка способа
+входа скрыта — платформу, через которую игрок сейчас вошёл, отсюда отвязать нельзя,
+показывается только плашка другого провайдера. Привязка провайдера, уже
 принадлежащего другому аккаунту, предлагает то же необратимое **слияние**, что и привязка
 email. Привязанного провайдера можно **отвязать** — кроме последнего
 оставшегося способа входа: он не отвязывается, чтобы аккаунт оставался достижимым.
@@ -212,7 +222,16 @@ e-mail) либо ввод фразы. Активные игры форфейтя
 внешний справочный словарь (gramota.ru для русских игр, scrabblewordfinder.org для английских),
 чтобы его посмотреть. Подсказки управляются настройками
 партии — разрешены ли они и сколько их у каждого игрока на старте — и расходуют
-личный кошелёк подсказок после исчерпания внутриигрового лимита. Партия
+личный кошелёк подсказок после исчерпания внутриигрового лимита. Против робота
+(**vs_ai**) подсказки, наоборот, **безлимитны и без кошелька**, но с idle-гейтом как
+анти-фрустрация: подсказка открывается, только когда игрок **застрял на ходу ~30 минут**
+(отсчёт от последнего хода робота; самый первый ход, до хода робота, исключён). Пока гейт
+закрыт, кнопка подсказки несёт маленький **🔒 замок**, а тап показывает, сколько осталось;
+замок снимается вживую в нужный момент. Один и тот же гейт работает **онлайн и офлайн**: отсчёт
+идёт по **ровному внутриигровому таймеру**, а не по системным часам, поэтому их перевод его не
+собьёт, а повторный вход перечитывает остаток — застрявший ход не забывается. Онлайн гейт
+**принуждает сервер** по своим часам (их игрок не тронет); vs_ai-подсказка не учитывается ни в
+одной статистике подсказок. Партия
 завершается, когда мешок пуст и игрок выложил стойку, после 6 подряд бесплодных
 ходов, по сдаче, либо по таймауту хода (от 5 минут до 24 часов, дефолт 24 часа):
 пропущенный ход означает авто-сдачу, кроме как когда игрок внутри своего
@@ -251,6 +270,45 @@ e-mail) либо ввод фразы. Активные игры форфейтя
 паузы), сохраняет ту же силу (по-прежнему играет на победу лишь примерно в 40% партий, с теми же
 редкими ходами вопреки плану, затухающими к эндшпилю), а чат, nudge и «добавить в друзья» выключены. Партии с ИИ — это **тренировка**: они не идут в статистику игрока.
 
+### Офлайн-режим
+Установленный веб-PWA со входом по подтверждённой почте может переключиться в осознанный
+**офлайн-режим** (Настройки → Режим игры). В офлайне приложение не обращается к сети: шапка синеет с
+меткой *Офлайн*, лобби показывает только сохранённые на устройстве игры, а сетевые поверхности
+отключены или скрыты (вкладка Статистика; вариант «случайный соперник» в Новой игре).
+Новая игра против робота создаёт локальную **vs_ai**-игру — он ходит
+целиком в браузере без бэкенда. Локальные игры хранятся на устройстве, видны только в офлайн-режиме и
+никогда не синхронизируются с аккаунтом. Чтобы игру можно было создать и сыграть без связи, приложение
+заранее, пока ещё онлайн, подгружает словари включённых игроком вариантов и (после установки)
+запускается из прекешированного шелла даже без сети. Переключение **в** офлайн сначала проверяет, что
+словари включённых вариантов есть на устройстве — если каких-то не хватает, оно их подгружает и недолго
+ждёт, а если подготовить их не удаётся, остаётся онлайн с короткой заметкой *нужен интернет* (загрузка
+продолжается в фоне, так что следующее переключение мгновенно). Режим привязан к устройству и
+сохраняется между запусками.
+
+В офлайне «с друзьями» в Новой игре запускает **локальную игру по очереди (hotseat)** на 2–4 человек
+за одним устройством. Сначала задаётся **пароль ведущего** — 4-значный PIN на клавиатуре в стиле
+экрана блокировки; пока он не задан, строки игроков заблокированы. Затем приложение спрашивает,
+играете ли вы сами — если да, вы занимаете первое место под именем из профиля. Вы называете каждого
+игрока (от 2 до 4; строки можно добавлять и удалять, удаление спрашивает пароль ведущего) и можете
+дать любому месту **свой необязательный PIN**. Во время игры доска видна всегда, но место с PIN
+вместо стойки показывает кнопку **«Разблокировать»**, пока владелец не введёт PIN, — так устройство
+передаётся из рук в руки, и только защищённое место прячет свои буквы; на каждом ходу замок
+возвращается. **Ведущий** (кнопка ведущего в игре) может по паролю ведущего **пропустить** ход
+текущего игрока, **исключить** игрока или **завершить игру досрочно** — досрочное завершение стирает
+партию без победителей и проигравших. Подсказки и чат в игре по очереди отключены. Нормально
+завершённая партия сохраняется в офлайн-лобби как любая другая; удаление любой игры по очереди —
+идущей или завершённой — из лобби спрашивает пароль ведущего, чтобы никто не стёр партию сразу после
+своего хода.
+
+Приложение также **само включает офлайн-режим**, когда не может достучаться до сети. При холодном
+запуске без связи оно переходит в офлайн на текущую сессию; когда устройство онлайн, но шлюз молчит
+несколько секунд, оно сперва спрашивает — *Нет связи. Включить офлайн-режим?*, с выбором **Включить**
+(уйти в офлайн) или **Ждать сеть** (продолжить попытки онлайн). Пока приложение открыто, потеря сети —
+режим полёта — переключает в офлайн автоматически, а её восстановление само возвращает онлайн.
+Самостоятельно включённый офлайн временный: он возвращается в онлайн, как только сеть появилась, и
+следующий запуск проверяет заново. **Осознанный** офлайн — тумблер в Настройках или **Включить** в том
+диалоге — это выбор игрока: он сохраняется и никогда не отменяется автоматически.
+
 ### Социальное: друзья, блок, чат, nudge
 Подружиться можно двумя способами: погасить **одноразовый код**, который выпускает
 другой игрок (шесть цифр, действует двенадцать часов), либо отправить **заявку
@@ -494,8 +552,19 @@ high-rate флага. С карточки пользователя операт
 **честно** — каждая получает свою долю по весу за цикл, равномерно размазанную, а не случайно — а
 кампания с несколькими сообщениями показывает их по очереди.
 
+Недефолтная кампания может нести собственные **цвета** — фон, текст и ссылку — чтобы рекламное или
+служебное сообщение выделялось на фоне нейтральной ленты. Цвета задаются двумя наборами: один
+применяется на **любой теме**, а необязательный второй переопределяет только **тёмную тему**, чтобы
+кампания хорошо читалась на обеих; рамка ленты выводится из фона автоматически. Кампанию можно также
+пометить как **срочную (urgent)**: срочная кампания показывается **всем** — даже платным игрокам,
+владельцам подсказок и пользователям с ролью `no_banner` — и, пока она активна, лента показывает
+**только её** (обычные кампании и домашняя дефолтная уступают место). Срочность — для настоящих
+системных уведомлений (тех.работы, сбои), а не для рекламы.
+
 Всем этим оператор управляет в админ-консоли по адресу **`/_gm/banners`**: создаёт, редактирует,
 включает/выключает и планирует кампании, пишет двуязычные сообщения кампании (переставляет и удаляет
-их) и задаёт общие **тайминги** показа (сколько держится сообщение, прокрутка слишком длинного, и
+их), выбирает необязательные цвета недефолтной кампании (нативный color-picker с живым превью ленты
-переход fade-out → пауза → fade-in между сообщениями). Дефолтную кампанию нельзя удалить, и в ней
+на светлой и тёмной темах) и помечает её срочной, а также задаёт общие **тайминги** показа (сколько
-всегда остаётся хотя бы одно сообщение.
+держится сообщение, прокрутка слишком длинного, и переход fade-out → пауза → fade-in между
+сообщениями). Дефолтную кампанию нельзя удалить, в ней всегда остаётся хотя бы одно сообщение, и она
+остаётся простой (без цветов, никогда не срочная).

docs/TESTING.md

@@ -20,7 +20,18 @@ tests or touching CI.
   derivation and the GCG share/copy/download choice, plus Playwright specs against the
   mock for the friends screen (code issue/redeem, accept a request), the lobby
   invitations section, the stats screen, profile editing, and the export chooser's
-  finished-only visibility + its signed-URL download flow (route-intercepted).
+  finished-only visibility + its signed-URL download flow (route-intercepted). The
+  **offline mode** spec (`e2e/offline.spec.ts`) plays a full device-local `vs_ai` game
+  end-to-end: it forces the installed-PWA display mode, enters offline through the
+  Settings toggle (whose readiness check fetches the enabled variants' dawgs), then creates
+  and plays a local game with a **pinned bag seed** (`window.__mock.setLocalSeed`, so the
+  rack is deterministic and the human can tap out a precomputed opening), asserting the
+  robot's real reply and the IndexedDB replay after a reload. A local game needs a real
+  dictionary, so the mock's `fetchDict` serves the per-variant dawgs from the preview
+  build's `/e2edict/`, copied in by `scripts/e2e-dict.mjs` from `E2E_DICT_DIR` — the `ui`
+  CI job fetches the `scrabble-dictionary` release like the Go jobs; locally it defaults to
+  the sibling `scrabble-solver/dawg`. These dawgs are never committed and never enter the
+  production build.
 - **Render sidecar** — `renderer/` (Node + skia-canvas executing the shared
   `ui/src/lib/gameimage.ts`) carries a `node --test` smoke: the committed fixture (a
   real self-played 35-move game) must rasterize to a plausible PNG

docs/UI_DESIGN.md

@@ -315,6 +315,19 @@ left. A **viewport size change** (e.g. a portrait↔landscape rotation) re-measu
 operator-set (`/_gm/banner-settings`). Under **reduce-motion** the fades collapse to an instant swap
 and a long message does not scroll.
 
+**Per-campaign colours.** A campaign may override the strip's colours (background, text, link). The
+engine carries the current message's campaign colours to the host, and `AdBanner` resolves them for
+the **rendered theme** (`lib/bannerColors`: dark ← dark-set ?? all-set, light ← all-set) and applies
+them as inline CSS variables scoped to `.ad` (`--ad-bg`, `--text-muted`, `--accent`, and a derived
+`--ad-border`) — so an override never leaks past the strip, and a campaign with no override keeps the
+neutral tokens. The border is computed from the background in JS (a luminance-aware nudge toward
+black/white — no CSS `color-mix`, which the old Android WebView floor lacks), matching the admin
+console's live preview. The resolution re-runs when the theme flips (a `[data-theme]` /
+`prefers-color-scheme` observer), so switching light↔dark repaints an overridden strip at once. An
+**urgent** campaign has no client-specific styling — it simply arrives (with its colours) as the only
+campaign in the feed; the preempt-and-show-everyone behaviour is entirely server-side (ARCHITECTURE
+§10).
+
 ## Result / status iconography (`lib/result.ts`)
 
 Lobby rows show two lines (opponents, then result + score) with a large place-based emoji

gateway/README.md

@@ -8,6 +8,10 @@ backend over REST/JSON, and bridges the backend's gRPC push stream to each
 client's in-app live channel. It **embeds the static UI build** (`go:embed`, baked
 in by the gateway image's node stage) and serves a **landing page** at `/` and the game
 **SPA** at `/app/` (web), `/telegram/` (the Telegram Mini App) and `/vk/` (the VK Mini App) — the single-origin model.
+The web SPA is an installable **PWA**: it serves `manifest.webmanifest` (unhashed from `ui/public/`,
+with the `.webmanifest` MIME type registered in-process — the distroless image has no
+`/etc/mime.types`) and the app-shell `sw.js` (built from `ui/src/sw.ts` by vite-plugin-pwa, which
+precaches the shell + assets so an installed PWA cold-launches offline).
 Hash-named `/assets/*` are served `immutable`; the HTML shells are `no-cache`. It can also serve the
 backend's admin console at `/_gm` behind HTTP Basic-Auth for a local non-caddy run;
 in the deployed contour the front caddy owns `/_gm` (see

gateway/internal/backendclient/api.go

@@ -42,6 +42,15 @@ type ProfileResp struct {
 	Email          string `json:"email"`
 	TelegramLinked bool   `json:"telegram_linked"`
 	VkLinked       bool   `json:"vk_linked"`
+	// DictVersions is the current dictionary version per game variant, forwarded verbatim
+	// into the Profile payload so an offline-capable client preloads the matching dawg.
+	DictVersions []DictVersion `json:"dict_versions,omitempty"`
+}
+
+// DictVersion pairs a game variant's stable label with its current dictionary version.
+type DictVersion struct {
+	Variant string `json:"variant"`
+	Version string `json:"version"`
 }
 
 // BannerResp is the advertising-banner block of an eligible viewer's profile: the
@@ -53,9 +62,18 @@ type BannerResp struct {
 
 // BannerCampaignResp is one campaign in the rotation feed: a GCD-reduced show
 // weight and its messages, in display order, already resolved to one language.
+// The override_* colours are the optional per-campaign palette (empty when the
+// campaign keeps the neutral theme tokens); they ride through to the client
+// verbatim, mirroring the backend DTO.
 type BannerCampaignResp struct {
-	Weight   int      `json:"weight"`
+	Weight           int      `json:"weight"`
-	Messages []string `json:"messages"`
+	Messages         []string `json:"messages"`
+	OverrideBg       string   `json:"override_bg,omitempty"`
+	OverrideFg       string   `json:"override_fg,omitempty"`
+	OverrideLink     string   `json:"override_link,omitempty"`
+	OverrideBgDark   string   `json:"override_bg_dark,omitempty"`
+	OverrideFgDark   string   `json:"override_fg_dark,omitempty"`
+	OverrideLinkDark string   `json:"override_link_dark,omitempty"`
 }
 
 // BannerTimingsResp mirrors the backend's global display timings.
@@ -163,13 +181,14 @@ type AlphabetEntryJSON struct {
 // StateResp is a player's view of a game. Rack carries wire alphabet indices;
 // Alphabet is present only when the request asked for it.
 type StateResp struct {
-	Game           GameResp            `json:"game"`
+	Game                  GameResp            `json:"game"`
-	Seat           int                 `json:"seat"`
+	Seat                  int                 `json:"seat"`
-	Rack           []int               `json:"rack"`
+	Rack                  []int               `json:"rack"`
-	BagLen         int                 `json:"bag_len"`
+	BagLen                int                 `json:"bag_len"`
-	HintsRemaining int                 `json:"hints_remaining"`
+	HintsRemaining        int                 `json:"hints_remaining"`
-	WalletBalance  int                 `json:"wallet_balance"`
+	WalletBalance         int                 `json:"wallet_balance"`
-	Alphabet       []AlphabetEntryJSON `json:"alphabet,omitempty"`
+	HintUnlockLeftSeconds int                 `json:"hint_unlock_left_seconds"`
+	Alphabet              []AlphabetEntryJSON `json:"alphabet,omitempty"`
 }
 
 // MatchResp reports an auto-match outcome.
@@ -280,10 +299,11 @@ func (c *Client) GuestAuth(ctx context.Context, browserTz string) (SessionResp,
 
 // EmailRequest asks the backend to mail a login code, provisioning the account on
 // first contact; browserTz (the client's detected "±HH:MM" UTC offset) seeds the new
-// account's time zone, since the email account is created here, not at login.
+// account's time zone, since the email account is created here, not at login. pwa marks a
-func (c *Client) EmailRequest(ctx context.Context, email, browserTz, language string) error {
+// request from an installed PWA, so the backend omits the one-tap confirm link from the email.
+func (c *Client) EmailRequest(ctx context.Context, email, browserTz, language string, pwa bool) error {
 	return c.do(ctx, http.MethodPost, "/api/v1/internal/sessions/email/request", "", "",
-		map[string]string{"email": email, "browser_tz": browserTz, "language": language}, nil)
+		map[string]any{"email": email, "browser_tz": browserTz, "language": language, "pwa": pwa}, nil)
 }
 
 // EmailLogin verifies a login code and mints a session.

gateway/internal/connectsrv/metrics.go

@@ -46,7 +46,13 @@ func newServerMetrics(meter metric.Meter) *serverMetrics {
 	}
 	h, err := meter.Float64Histogram("edge_request_duration",
 		metric.WithUnit("s"),
-		metric.WithDescription("Seconds to serve one Connect Execute call, by message type and result."))
+		metric.WithDescription("Seconds to serve one Connect Execute call, by message type and result."),
+		// Explicit second-scale buckets. The durations are recorded in seconds, so the SDK's
+		// default millisecond-calibrated boundaries (first boundary 5) would bin every sub-5s
+		// request into one bucket — making histogram_quantile(0.99) interpolate to ~4.95s
+		// regardless of the real latency, which flapped the >1s edge-latency alert. These
+		// boundaries straddle the 1s SLO so the p99 reflects real (mostly sub-second) latency.
+		metric.WithExplicitBucketBoundaries(0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10))
 	if err != nil {
 		h, _ = noop.NewMeterProvider().Meter(meterName).Float64Histogram("edge_request_duration")
 	}

gateway/internal/connectsrv/metrics_test.go

@@ -29,6 +29,7 @@ func TestEdgeMetric(t *testing.T) {
 
 	type key struct{ messageType, result string }
 	counts := map[key]uint64{}
+	var bounds []float64
 	for _, sm := range rm.ScopeMetrics {
 		for _, md := range sm.Metrics {
 			if md.Name != "edge_request_duration" {
@@ -42,6 +43,7 @@ func TestEdgeMetric(t *testing.T) {
 				mt, _ := dp.Attributes.Value(attribute.Key("message_type"))
 				res, _ := dp.Attributes.Value(attribute.Key("result"))
 				counts[key{mt.AsString(), res.AsString()}] += dp.Count
+				bounds = dp.Bounds
 			}
 		}
 	}
@@ -51,6 +53,19 @@ func TestEdgeMetric(t *testing.T) {
 	if got := counts[key{"auth.guest", "domain"}]; got != 1 {
 		t.Errorf("edge auth.guest/domain = %d, want 1", got)
 	}
+	// The buckets must be second-scaled. The default (millisecond-calibrated) boundaries have no
+	// boundary between 0 and 5, so every sub-5s request bins into one bucket and p99 interpolates
+	// to ~4.95s, flapping the >1s alert. Require at least one sub-second boundary.
+	subSecond := false
+	for _, b := range bounds {
+		if b > 0 && b < 1 {
+			subSecond = true
+			break
+		}
+	}
+	if !subSecond {
+		t.Errorf("edge_request_duration bounds = %v, want sub-second boundaries (seconds-scaled)", bounds)
+	}
 }
 
 // TestRateLimitedMetric records limiter rejections through a manual reader and

gateway/internal/transcode/encode.go

@@ -95,6 +95,7 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 		banner = encodeBanner(b, *p.Banner)
 	}
 	prefs := buildStringVector(b, p.VariantPreferences, fb.ProfileStartVariantPreferencesVector)
+	dictVersions := encodeDictVersions(b, p.DictVersions)
 	fb.ProfileStart(b)
 	fb.ProfileAddUserId(b, uid)
 	fb.ProfileAddDisplayName(b, name)
@@ -111,6 +112,9 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	fb.ProfileAddEmail(b, email)
 	fb.ProfileAddTelegramLinked(b, p.TelegramLinked)
 	fb.ProfileAddVkLinked(b, p.VkLinked)
+	if dictVersions != 0 {
+		fb.ProfileAddDictVersions(b, dictVersions)
+	}
 	if p.Banner != nil {
 		fb.ProfileAddBanner(b, banner)
 	}
@@ -118,6 +122,48 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	return b.FinishedBytes()
 }
 
+// encodeDictVersions builds the Profile's dict_versions vector — one DictVersion table per
+// variant/version pair — and returns its offset, or 0 when there are none (the field is then
+// omitted). Every child table and its strings are created before the vector is opened, per the
+// FlatBuffers rule against nesting a table under one still being built; the caller invokes it
+// before ProfileStart for the same reason.
+func encodeDictVersions(b *flatbuffers.Builder, dvs []backendclient.DictVersion) flatbuffers.UOffsetT {
+	if len(dvs) == 0 {
+		return 0
+	}
+	offsets := make([]flatbuffers.UOffsetT, len(dvs))
+	for i, dv := range dvs {
+		variant := b.CreateString(dv.Variant)
+		version := b.CreateString(dv.Version)
+		fb.DictVersionStart(b)
+		fb.DictVersionAddVariant(b, variant)
+		fb.DictVersionAddVersion(b, version)
+		offsets[i] = fb.DictVersionEnd(b)
+	}
+	fb.ProfileStartDictVersionsVector(b, len(offsets))
+	for i := len(offsets) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(offsets[i])
+	}
+	return b.EndVector(len(offsets))
+}
+
+// optString creates a FlatBuffers string for a non-empty value, or 0 to omit the
+// optional field (the client then reads it as absent).
+func optString(b *flatbuffers.Builder, s string) flatbuffers.UOffsetT {
+	if s == "" {
+		return 0
+	}
+	return b.CreateString(s)
+}
+
+// addOptString adds an optional string slot only when it was created (a 0 offset
+// leaves the field absent). add is the generated BannerCampaignAdd* setter.
+func addOptString(b *flatbuffers.Builder, add func(*flatbuffers.Builder, flatbuffers.UOffsetT), off flatbuffers.UOffsetT) {
+	if off != 0 {
+		add(b, off)
+	}
+}
+
 // encodeBanner builds a BannerInfo table from the resolved banner block and
 // returns its offset. It is bottom-up: each campaign's messages vector and table
 // are built first, then the campaigns vector, then the BannerInfo table. The
@@ -134,9 +180,23 @@ func encodeBanner(b *flatbuffers.Builder, banner backendclient.BannerResp) flatb
 			b.PrependUOffsetT(msgOffsets[j])
 		}
 		msgs := b.EndVector(len(msgOffsets))
+		// The optional colour strings must be created before the table starts; an
+		// empty colour is omitted (offset 0), so the client reads it as absent.
+		obg := optString(b, c.OverrideBg)
+		ofg := optString(b, c.OverrideFg)
+		olink := optString(b, c.OverrideLink)
+		obgD := optString(b, c.OverrideBgDark)
+		ofgD := optString(b, c.OverrideFgDark)
+		olinkD := optString(b, c.OverrideLinkDark)
 		fb.BannerCampaignStart(b)
 		fb.BannerCampaignAddWeight(b, int32(c.Weight))
 		fb.BannerCampaignAddMessages(b, msgs)
+		addOptString(b, fb.BannerCampaignAddOverrideBg, obg)
+		addOptString(b, fb.BannerCampaignAddOverrideFg, ofg)
+		addOptString(b, fb.BannerCampaignAddOverrideLink, olink)
+		addOptString(b, fb.BannerCampaignAddOverrideBgDark, obgD)
+		addOptString(b, fb.BannerCampaignAddOverrideFgDark, ofgD)
+		addOptString(b, fb.BannerCampaignAddOverrideLinkDark, olinkD)
 		campOffsets[i] = fb.BannerCampaignEnd(b)
 	}
 	fb.BannerInfoStartCampaignsVector(b, len(campOffsets))
@@ -239,13 +299,14 @@ func toWireState(s backendclient.StateResp) wire.StateView {
 		alphabet[i] = wire.AlphabetEntry{Index: e.Index, Letter: e.Letter, Value: e.Value}
 	}
 	return wire.StateView{
-		Game:           toWireGame(s.Game),
+		Game:                  toWireGame(s.Game),
-		Seat:           s.Seat,
+		Seat:                  s.Seat,
-		Rack:           s.Rack,
+		Rack:                  s.Rack,
-		BagLen:         s.BagLen,
+		BagLen:                s.BagLen,
-		HintsRemaining: s.HintsRemaining,
+		HintsRemaining:        s.HintsRemaining,
-		WalletBalance:  s.WalletBalance,
+		WalletBalance:         s.WalletBalance,
-		Alphabet:       alphabet,
+		HintUnlockLeftSeconds: s.HintUnlockLeftSeconds,
+		Alphabet:              alphabet,
 	}
 }
 

gateway/internal/transcode/transcode.go

@@ -253,7 +253,7 @@ func authGuestHandler(backend *backendclient.Client) Handler {
 func authEmailRequestHandler(backend *backendclient.Client) Handler {
 	return func(ctx context.Context, req Request) ([]byte, error) {
 		in := fb.GetRootAsEmailRequestRequest(req.Payload, 0)
-		if err := backend.EmailRequest(ctx, string(in.Email()), string(in.BrowserTz()), string(in.Language())); err != nil {
+		if err := backend.EmailRequest(ctx, string(in.Email()), string(in.BrowserTz()), string(in.Language()), in.Pwa()); err != nil {
 			return nil, err
 		}
 		return encodeAck(true), nil

gateway/internal/transcode/transcode_banner_test.go

@@ -61,6 +61,54 @@ func TestProfileGetEncodesBanner(t *testing.T) {
 	}
 }
 
+// TestProfileGetEncodesBannerColors verifies the gateway carries a campaign's
+// optional colour overrides into the FlatBuffers payload, and leaves an absent
+// colour (or an absent set) empty so the client falls back to the theme tokens.
+func TestProfileGetEncodesBannerColors(t *testing.T) {
+	backend, cleanup := fakeBackend(t, func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte(`{"user_id":"u-1","display_name":"Kaya","preferred_language":"en",` +
+			`"banner":{"campaigns":[` +
+			`{"weight":1,"messages":["promo-en"],` +
+			`"override_bg":"#aa0000","override_fg":"#ffffff","override_link":"#ffdd00",` +
+			`"override_bg_dark":"#330000","override_fg_dark":"#eeeeee","override_link_dark":"#ffcc00"},` +
+			`{"weight":1,"messages":["plain-en"]}],` +
+			`"timings":{"hold_ms":60000,"edge_pause_ms":5000,"scroll_px_per_sec":40,` +
+			`"fade_out_ms":1000,"gap_ms":250,"fade_in_ms":1000}}}`))
+	})
+	defer cleanup()
+
+	reg := transcode.NewRegistry(backend, nil)
+	op, _ := reg.Lookup(transcode.MsgProfileGet)
+	payload, err := op.Handler(context.Background(), transcode.Request{UserID: "u-1"})
+	if err != nil {
+		t.Fatalf("handler: %v", err)
+	}
+	banner := fb.GetRootAsProfile(payload, 0).Banner(nil)
+	if banner == nil {
+		t.Fatal("profile carries no banner block")
+	}
+	var c fb.BannerCampaign
+	banner.Campaigns(&c, 0)
+	if got := string(c.OverrideBg()); got != "#aa0000" {
+		t.Errorf("override_bg = %q, want #aa0000", got)
+	}
+	if got := string(c.OverrideLink()); got != "#ffdd00" {
+		t.Errorf("override_link = %q, want #ffdd00", got)
+	}
+	if got := string(c.OverrideBgDark()); got != "#330000" {
+		t.Errorf("override_bg_dark = %q, want #330000", got)
+	}
+	if got := string(c.OverrideLinkDark()); got != "#ffcc00" {
+		t.Errorf("override_link_dark = %q, want #ffcc00", got)
+	}
+	// The second campaign has no override: every colour field must be absent (nil).
+	banner.Campaigns(&c, 1)
+	if c.OverrideBg() != nil || c.OverrideFg() != nil || c.OverrideLink() != nil ||
+		c.OverrideBgDark() != nil || c.OverrideFgDark() != nil || c.OverrideLinkDark() != nil {
+		t.Error("plain campaign unexpectedly carries a colour override")
+	}
+}
+
 // TestProfileGetNoBanner verifies an ineligible viewer's profile carries no
 // banner block (the backend omits it).
 func TestProfileGetNoBanner(t *testing.T) {

gateway/internal/transcode/transcode_test.go

@@ -59,7 +59,7 @@ func TestGameStateRoundTripForwardsUserID(t *testing.T) {
 		if r.URL.Path != "/api/v1/user/games/g-1/state" {
 			t.Errorf("unexpected path %q", r.URL.Path)
 		}
-		_, _ = w.Write([]byte(`{"game":{"id":"g-1","variant":"scrabble_en","status":"active","players":2,"to_move":1,"seats":[{"seat":0,"account_id":"u-7","score":5}]},"seat":0,"rack":[0,1],"bag_len":80,"hints_remaining":4,"wallet_balance":3}`))
+		_, _ = w.Write([]byte(`{"game":{"id":"g-1","variant":"scrabble_en","status":"active","players":2,"to_move":1,"seats":[{"seat":0,"account_id":"u-7","score":5}]},"seat":0,"rack":[0,1],"bag_len":80,"hints_remaining":4,"wallet_balance":3,"hint_unlock_left_seconds":1200}`))
 	})
 	defer cleanup()
 
@@ -77,8 +77,8 @@ func TestGameStateRoundTripForwardsUserID(t *testing.T) {
 		t.Fatalf("handler: %v", err)
 	}
 	st := fb.GetRootAsStateView(payload, 0)
-	if st.BagLen() != 80 || st.RackLength() != 2 || st.HintsRemaining() != 4 || st.WalletBalance() != 3 {
+	if st.BagLen() != 80 || st.RackLength() != 2 || st.HintsRemaining() != 4 || st.WalletBalance() != 3 || st.HintUnlockLeftSeconds() != 1200 {
-		t.Fatalf("state decoded wrong: bag=%d rack=%d hints=%d wallet=%d", st.BagLen(), st.RackLength(), st.HintsRemaining(), st.WalletBalance())
+		t.Fatalf("state decoded wrong: bag=%d rack=%d hints=%d wallet=%d unlockLeft=%d", st.BagLen(), st.RackLength(), st.HintsRemaining(), st.WalletBalance(), st.HintUnlockLeftSeconds())
 	}
 	game := st.Game(nil)
 	if game == nil || string(game.Id()) != "g-1" || string(game.Variant()) != "scrabble_en" || game.ToMove() != 1 {

gateway/internal/webui/webui.go

@@ -17,6 +17,7 @@ package webui
 import (
 	"embed"
 	"io/fs"
+	"mime"
 	"net/http"
 	"path"
 	"strings"
@@ -35,13 +36,25 @@ func distFS() fs.FS {
 	return sub
 }
 
-// Handler serves the embedded UI. An existing file is served directly (hash-named assets get
+// init registers the MIME type for .webmanifest, which Go's built-in table lacks and the
-// an immutable cache); every other path falls back to indexName (the SPA shell) so a
+// distroless runtime image has no /etc/mime.types to supply. Without it the PWA Web App Manifest
-// client-side deep link still loads. When stripPrefix is non-empty it is removed from the
+// served under /app/ would be content-sniffed to text/plain, which some browsers reject.
-// request path before lookup, so the same build serves under a sub-path (e.g. "/app/" or
+func init() {
-// "/telegram/").
+	_ = mime.AddExtensionType(".webmanifest", "application/manifest+json")
+}
+
+// Handler serves the compile-time embedded UI build over the public edge — the game SPA under
+// /app/, /telegram/ and /vk/. It delegates to handlerFor over the embedded dist/.
 func Handler(stripPrefix, indexName string) http.Handler {
-	content := distFS()
+	return handlerFor(distFS(), stripPrefix, indexName)
+}
+
+// handlerFor serves content as the UI: an existing file is served directly (hash-named assets get
+// an immutable cache); every other path falls back to indexName (the SPA shell) so a client-side
+// deep link still loads. When stripPrefix is non-empty it is removed from the request path before
+// lookup, so the same build serves under a sub-path (e.g. "/app/" or "/telegram/"). Split from
+// Handler so it can be exercised over an in-memory fs.FS in tests.
+func handlerFor(content fs.FS, stripPrefix, indexName string) http.Handler {
 	files := http.FileServer(http.FS(content))
 	h := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		name := strings.TrimPrefix(path.Clean("/"+r.URL.Path), "/")
@@ -58,6 +71,11 @@ func Handler(stripPrefix, indexName string) http.Handler {
 		// app (notably a relaunched Telegram Mini App) is a cache hit, not a re-download.
 		if strings.HasPrefix(name, "assets/") {
 			w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+		} else if name == "sw.js" {
+			// The service worker must be revalidated on every load so a new deploy's worker (and its
+			// fresh precache manifest) is picked up promptly; a cached sw.js would strand clients on
+			// the old build. The worker's network-first navigation then serves the fresh shell online.
+			w.Header().Set("Cache-Control", "no-cache")
 		}
 		files.ServeHTTP(w, r)
 	})

gateway/internal/webui/webui_test.go

@@ -6,6 +6,7 @@ import (
 	"net/http/httptest"
 	"strings"
 	"testing"
+	"testing/fstest"
 )
 
 // get drives the handler with a GET for the given path and returns the response.
@@ -55,3 +56,60 @@ func TestAppMountServesShellStripsPrefixAndCachesAssets(t *testing.T) {
 		}
 	}
 }
+
+// testFS mirrors what Vite emits into dist/: the SPA shell, the PWA manifest + service worker at
+// the root (copied from ui/public), and a hash-named asset. The compile-time embedded dist/ holds
+// only a placeholder shell, so the manifest/sw.js serving is exercised over this in-memory FS.
+func testFS() fstest.MapFS {
+	return fstest.MapFS{
+		"index.html":           {Data: []byte("<!doctype html><title>shell</title>")},
+		"manifest.webmanifest": {Data: []byte(`{"name":"Эрудит"}`)},
+		"sw.js":                {Data: []byte("self.addEventListener('fetch', () => {});")},
+		"assets/app-abc123.js": {Data: []byte("export const x = 1;")},
+	}
+}
+
+// TestHandlerServesManifestWithManifestType: the PWA manifest is served with the manifest MIME
+// type (registered in init, since the distroless image has no /etc/mime.types), not sniffed to
+// text/plain, which some browsers reject.
+func TestHandlerServesManifestWithManifestType(t *testing.T) {
+	h := handlerFor(testFS(), "/app/", "index.html")
+	resp := get(t, h, "/app/manifest.webmanifest")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("status = %d, want 200", resp.StatusCode)
+	}
+	if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "application/manifest+json") {
+		t.Errorf("Content-Type = %q, want application/manifest+json", ct)
+	}
+}
+
+// TestHandlerServesServiceWorkerAsJavaScript: sw.js is served as JavaScript from the root, so its
+// registration (scope /app/) succeeds.
+func TestHandlerServesServiceWorkerAsJavaScript(t *testing.T) {
+	h := handlerFor(testFS(), "/app/", "index.html")
+	resp := get(t, h, "/app/sw.js")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("status = %d, want 200", resp.StatusCode)
+	}
+	if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/javascript") {
+		t.Errorf("Content-Type = %q, want text/javascript", ct)
+	}
+	// Revalidated on every load so a new deploy's worker (and its fresh precache) is picked up.
+	if cc := resp.Header.Get("Cache-Control"); cc != "no-cache" {
+		t.Errorf("sw.js Cache-Control = %q, want no-cache", cc)
+	}
+}
+
+// TestHandlerFallsBackToShellForUnknownManifestPath guards the trap: a manifest/sw path NOT emitted
+// into dist/ falls back to the SPA shell as text/html, on which SW registration would fail. The two
+// tests above pin that the real files are served instead of the shell.
+func TestHandlerFallsBackToShellForUnknownManifestPath(t *testing.T) {
+	h := handlerFor(testFS(), "/app/", "index.html")
+	resp := get(t, h, "/app/not-emitted.webmanifest")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("status = %d, want 200", resp.StatusCode)
+	}
+	if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/html") {
+		t.Errorf("Content-Type = %q, want text/html (SPA shell fallback)", ct)
+	}
+}

pkg/fbs/scrabble.fbs

@@ -138,6 +138,11 @@ table EmailRequestRequest {
   email:string;
   browser_tz:string;
   language:string;
+  // Set when the request originates from an installed PWA (standalone display mode): the
+  // backend then omits the one-tap confirm link from the login email so the code is typed in
+  // the same window, avoiding a link that opens in a separate browser (a different storage
+  // context) where the minted session could not reach the PWA.
+  pwa:bool;
 }
 
 // EmailLoginRequest logs in to the account owning email (provisioned at the
@@ -180,10 +185,20 @@ table Ack {
 // BannerCampaign is one campaign in the rotation feed: a GCD-reduced show weight
 // (the client runs a smooth weighted round-robin over campaigns by this weight)
 // and its messages in display order, each already resolved to the viewer's bot
-// language (the stored en/ru pair is picked server-side).
+// language (the stored en/ru pair is picked server-side). The override_* colours
+// are an optional per-campaign palette: override_bg/fg/link paint the strip on
+// every theme, and the *_dark trio further overrides the dark theme (the client
+// resolves dark ← dark ?? all ?? token, light ← all ?? token). Empty means the
+// campaign keeps the neutral theme tokens (all added trailing — backward-compatible).
 table BannerCampaign {
   weight:int;
   messages:[string];
+  override_bg:string;
+  override_fg:string;
+  override_link:string;
+  override_bg_dark:string;
+  override_fg_dark:string;
+  override_link_dark:string;
 }
 
 // BannerInfo is the advertising-banner block of an eligible viewer's profile: the
@@ -208,6 +223,13 @@ table BannerInfo {
 // suppresses out-of-app platform push, leaving only the in-app live stream. banner
 // carries the advertising-banner block for an eligible viewer, absent otherwise
 // (all added trailing — backward-compatible).
+// DictVersion is one variant's current dictionary version, carried on the profile so an offline
+// client learns it from an existing cold-start request (no extra call for a rarely-used feature).
+table DictVersion {
+  variant:string;
+  version:string;
+}
+
 table Profile {
   user_id:string;
   display_name:string;
@@ -230,6 +252,10 @@ table Profile {
   email:string;
   telegram_linked:bool;
   vk_linked:bool;
+  // dict_versions carries each variant's current dictionary version so an offline client can
+  // preload the right dictionary and pin a new local game without a separate request (added
+  // trailing — backward-compatible).
+  dict_versions:[DictVersion];
 }
 
 // BlockStatus reports the caller's current manual block. The UI fetches it after any operation
@@ -290,6 +316,13 @@ table StateView {
   // the wallet is a single global figure the client keeps live across games (added trailing —
   // backward-compatible).
   wallet_balance:int;
+  // hint_unlock_left_seconds is, for a vs_ai game, how many seconds until the idle hint unlocks
+  // (the robot's last move plus the idle window, computed from the SERVER clock online / the device
+  // clock offline, capped at the window and floored at 0); 0 for a human's first move (no robot move
+  // yet) or a non-vs_ai game. The client anchors a MONOTONIC countdown (performance.now()) to it, so a
+  // client clock change cannot skew it — see lib/hints. Seconds granularity is enough; sent trailing
+  // (additive, backward-compatible).
+  hint_unlock_left_seconds:int;
 }
 
 // GameActionRequest carries just a game id (pass / resign / hint / history).

pkg/fbs/scrabblefb/BannerCampaign.go

@@ -70,8 +70,56 @@ func (rcv *BannerCampaign) MessagesLength() int {
 	return 0
 }
 
+func (rcv *BannerCampaign) OverrideBg() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(8))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *BannerCampaign) OverrideFg() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(10))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *BannerCampaign) OverrideLink() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(12))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *BannerCampaign) OverrideBgDark() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(14))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *BannerCampaign) OverrideFgDark() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(16))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *BannerCampaign) OverrideLinkDark() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(18))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
 func BannerCampaignStart(builder *flatbuffers.Builder) {
-	builder.StartObject(2)
+	builder.StartObject(8)
 }
 func BannerCampaignAddWeight(builder *flatbuffers.Builder, weight int32) {
 	builder.PrependInt32Slot(0, weight, 0)
@@ -82,6 +130,24 @@ func BannerCampaignAddMessages(builder *flatbuffers.Builder, messages flatbuffer
 func BannerCampaignStartMessagesVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
 	return builder.StartVector(4, numElems, 4)
 }
+func BannerCampaignAddOverrideBg(builder *flatbuffers.Builder, overrideBg flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(2, flatbuffers.UOffsetT(overrideBg), 0)
+}
+func BannerCampaignAddOverrideFg(builder *flatbuffers.Builder, overrideFg flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(3, flatbuffers.UOffsetT(overrideFg), 0)
+}
+func BannerCampaignAddOverrideLink(builder *flatbuffers.Builder, overrideLink flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(4, flatbuffers.UOffsetT(overrideLink), 0)
+}
+func BannerCampaignAddOverrideBgDark(builder *flatbuffers.Builder, overrideBgDark flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(5, flatbuffers.UOffsetT(overrideBgDark), 0)
+}
+func BannerCampaignAddOverrideFgDark(builder *flatbuffers.Builder, overrideFgDark flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(6, flatbuffers.UOffsetT(overrideFgDark), 0)
+}
+func BannerCampaignAddOverrideLinkDark(builder *flatbuffers.Builder, overrideLinkDark flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(7, flatbuffers.UOffsetT(overrideLinkDark), 0)
+}
 func BannerCampaignEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/fbs/scrabblefb/DictVersion.go

@@ -0,0 +1,71 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type DictVersion struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsDictVersion(buf []byte, offset flatbuffers.UOffsetT) *DictVersion {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &DictVersion{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishDictVersionBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsDictVersion(buf []byte, offset flatbuffers.UOffsetT) *DictVersion {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &DictVersion{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedDictVersionBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *DictVersion) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *DictVersion) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *DictVersion) Variant() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *DictVersion) Version() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func DictVersionStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func DictVersionAddVariant(builder *flatbuffers.Builder, variant flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(variant), 0)
+}
+func DictVersionAddVersion(builder *flatbuffers.Builder, version flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(version), 0)
+}
+func DictVersionEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/EmailRequestRequest.go

@@ -65,8 +65,20 @@ func (rcv *EmailRequestRequest) Language() []byte {
 	return nil
 }
 
+func (rcv *EmailRequestRequest) Pwa() bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(10))
+	if o != 0 {
+		return rcv._tab.GetBool(o + rcv._tab.Pos)
+	}
+	return false
+}
+
+func (rcv *EmailRequestRequest) MutatePwa(n bool) bool {
+	return rcv._tab.MutateBoolSlot(10, n)
+}
+
 func EmailRequestRequestStart(builder *flatbuffers.Builder) {
-	builder.StartObject(3)
+	builder.StartObject(4)
 }
 func EmailRequestRequestAddEmail(builder *flatbuffers.Builder, email flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(email), 0)
@@ -77,6 +89,9 @@ func EmailRequestRequestAddBrowserTz(builder *flatbuffers.Builder, browserTz fla
 func EmailRequestRequestAddLanguage(builder *flatbuffers.Builder, language flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(2, flatbuffers.UOffsetT(language), 0)
 }
+func EmailRequestRequestAddPwa(builder *flatbuffers.Builder, pwa bool) {
+	builder.PrependBoolSlot(3, pwa, false)
+}
 func EmailRequestRequestEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/fbs/scrabblefb/Profile.go

@@ -211,8 +211,28 @@ func (rcv *Profile) MutateVkLinked(n bool) bool {
 	return rcv._tab.MutateBoolSlot(34, n)
 }
 
+func (rcv *Profile) DictVersions(obj *DictVersion, j int) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(36))
+	if o != 0 {
+		x := rcv._tab.Vector(o)
+		x += flatbuffers.UOffsetT(j) * 4
+		x = rcv._tab.Indirect(x)
+		obj.Init(rcv._tab.Bytes, x)
+		return true
+	}
+	return false
+}
+
+func (rcv *Profile) DictVersionsLength() int {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(36))
+	if o != 0 {
+		return rcv._tab.VectorLen(o)
+	}
+	return 0
+}
+
 func ProfileStart(builder *flatbuffers.Builder) {
-	builder.StartObject(16)
+	builder.StartObject(17)
 }
 func ProfileAddUserId(builder *flatbuffers.Builder, userId flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(userId), 0)
@@ -265,6 +285,12 @@ func ProfileAddTelegramLinked(builder *flatbuffers.Builder, telegramLinked bool)
 func ProfileAddVkLinked(builder *flatbuffers.Builder, vkLinked bool) {
 	builder.PrependBoolSlot(15, vkLinked, false)
 }
+func ProfileAddDictVersions(builder *flatbuffers.Builder, dictVersions flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(16, flatbuffers.UOffsetT(dictVersions), 0)
+}
+func ProfileStartDictVersionsVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
+	return builder.StartVector(4, numElems, 4)
+}
 func ProfileEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/fbs/scrabblefb/StateView.go

@@ -156,8 +156,20 @@ func (rcv *StateView) MutateWalletBalance(n int32) bool {
 	return rcv._tab.MutateInt32Slot(16, n)
 }
 
+func (rcv *StateView) HintUnlockLeftSeconds() int32 {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(18))
+	if o != 0 {
+		return rcv._tab.GetInt32(o + rcv._tab.Pos)
+	}
+	return 0
+}
+
+func (rcv *StateView) MutateHintUnlockLeftSeconds(n int32) bool {
+	return rcv._tab.MutateInt32Slot(18, n)
+}
+
 func StateViewStart(builder *flatbuffers.Builder) {
-	builder.StartObject(7)
+	builder.StartObject(8)
 }
 func StateViewAddGame(builder *flatbuffers.Builder, game flatbuffers.UOffsetT) {
 	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(game), 0)
@@ -186,6 +198,9 @@ func StateViewStartAlphabetVector(builder *flatbuffers.Builder, numElems int) fl
 func StateViewAddWalletBalance(builder *flatbuffers.Builder, walletBalance int32) {
 	builder.PrependInt32Slot(6, walletBalance, 0)
 }
+func StateViewAddHintUnlockLeftSeconds(builder *flatbuffers.Builder, hintUnlockLeftSeconds int32) {
+	builder.PrependInt32Slot(7, hintUnlockLeftSeconds, 0)
+}
 func StateViewEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

pkg/wire/build.go

@@ -87,13 +87,14 @@ type AlphabetEntry struct {
 // (wire alphabet indices), bag size and hint budget. Alphabet is set only when the
 // recipient may not have cached the variant's display table yet.
 type StateView struct {
-	Game           GameView
+	Game                  GameView
-	Seat           int
+	Seat                  int
-	Rack           []int
+	Rack                  []int
-	BagLen         int
+	BagLen                int
-	HintsRemaining int
+	HintsRemaining        int
-	WalletBalance  int
+	WalletBalance         int
-	Alphabet       []AlphabetEntry
+	HintUnlockLeftSeconds int
+	Alphabet              []AlphabetEntry
 }
 
 // AccountRef is a referenced account with its display name resolved.
@@ -256,6 +257,7 @@ func BuildStateView(b *flatbuffers.Builder, s StateView) flatbuffers.UOffsetT {
 	fb.StateViewAddBagLen(b, int32(s.BagLen))
 	fb.StateViewAddHintsRemaining(b, int32(s.HintsRemaining))
 	fb.StateViewAddWalletBalance(b, int32(s.WalletBalance))
+	fb.StateViewAddHintUnlockLeftSeconds(b, int32(s.HintUnlockLeftSeconds))
 	if hasAlphabet {
 		fb.StateViewAddAlphabet(b, alphabet)
 	}

ui/e2e/hotseat.spec.ts

@@ -0,0 +1,126 @@
+import { test, expect, type Page } from './fixtures';
+
+// Offline pass-and-play (hotseat) is offered only in offline mode, which is gated to an installed
+// standalone PWA with a confirmed email. The mock account has an email; force standalone so the
+// Settings offline toggle shows.
+async function forceStandalone(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const orig = window.matchMedia.bind(window);
+    window.matchMedia = (q: string) =>
+      (q.includes('display-mode: standalone')
+        ? { matches: true, media: q, onchange: null, addEventListener() {}, removeEventListener() {}, addListener() {}, removeListener() {}, dispatchEvent: () => false }
+        : orig(q)) as MediaQueryList;
+  });
+}
+
+async function enterLobby(page: Page): Promise<void> {
+  await page.getByRole('button', { name: /guest|гост/i }).first().click();
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+async function goOffline(page: Page): Promise<void> {
+  await page.locator('button.tab').nth(2).click(); // Settings
+  await page.getByRole('button', { name: /^(Offline|Оффлайн)$/ }).click();
+  await expect(page.locator('header.nav.offline')).toBeVisible({ timeout: 15000 });
+  await page.getByRole('button', { name: /Back|Назад/i }).click();
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+// typePin clicks the on-screen keypad digits (the pad has no OK button — the 4th digit is the action).
+// It first waits for the dots to be empty, so a call made right after a previous entry does not lose
+// digits during the 250 ms verdict pause (the 4th digit → pause → clear/advance).
+async function typePin(page: Page, digits: string): Promise<void> {
+  await expect(page.locator('.pad .dot.on')).toHaveCount(0);
+  for (const d of digits) await page.locator('.pad .key', { hasText: d }).click();
+}
+
+test.describe('offline hotseat (pass-and-play)', () => {
+  test('create with a locked seat, unlock, host-skip, terminate from the lobby', async ({ page }) => {
+    await forceStandalone(page);
+    await page.goto('/');
+    await enterLobby(page);
+    await goOffline(page);
+
+    // A known seed: the bag deals a full rack deterministically, AND the seeded seating shuffle keeps
+    // the roster order (Ann first) so the locked-seat assertions below are stable. (Seat order is
+    // randomised at start; the shuffle is seed-driven — seed '1' would seat Bob first, '2' Ann first.)
+    await page.evaluate(() => (window as unknown as { __mock: { setLocalSeed(s: string): void } }).__mock.setLocalSeed('2'));
+
+    // New game -> the offline mode selector now offers "with friends" (hotseat).
+    await page.locator('button.tab').nth(0).click();
+    await page.getByRole('button', { name: /With friends|друзьями/i }).click();
+
+    // The player rows are disabled until the mandatory host (master) PIN is set.
+    await expect(page.locator('.pname').first()).toBeDisabled();
+
+    // Set the host PIN (enter + confirm), then decline taking a seat.
+    await page.locator('.hostpin .plink').click();
+    await typePin(page, '9999');
+    await typePin(page, '9999');
+    await page.getByRole('button', { name: /^(No|Нет)$/ }).click();
+
+    // Pick the English variant (the plaques mirror Quick Match; "Scrabble" is the Latin English name).
+    await page.locator('.variant', { hasText: 'Scrabble' }).click();
+
+    // Two players: Ann (PIN-locked) and Bob (open).
+    await page.locator('.pname').nth(0).fill('Ann');
+    await page.locator('.pname').nth(1).fill('Bob');
+
+    // Row-delete: a 3rd player's kebab asks the host PIN, which ARMS a ❌ (not a silent delete);
+    // tapping the ❌ removes the row.
+    await page.getByRole('button', { name: /Add player|Добавить/i }).click();
+    await expect(page.locator('.prow')).toHaveCount(3);
+    await page.locator('.prow').nth(2).locator('.pkebab').click();
+    await typePin(page, '9999');
+    const rowDel = page.locator('.prow').nth(2).locator('.prow-del');
+    await expect(rowDel).toBeVisible();
+    await rowDel.click();
+    await expect(page.locator('.prow')).toHaveCount(2);
+
+    // Lock Ann's seat with a PIN.
+    await page.locator('.prow').nth(0).locator('.plink').click();
+    await typePin(page, '1234');
+    await typePin(page, '1234');
+
+    await page.locator('button.invite').click();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+
+    // Ann is to move and PIN-locked: the board is visible but her rack is withheld behind Unlock.
+    await expect(page.locator('.unlock')).toBeVisible();
+    await expect(page.locator('.rack .tile')).toHaveCount(0);
+
+    // A wrong PIN keeps it locked; the right PIN reveals the full rack.
+    await page.locator('.unlock').click();
+    await typePin(page, '0000');
+    await expect(page.locator('.pad')).toBeVisible(); // still open after a wrong PIN
+    await typePin(page, '1234');
+    await expect(page.locator('.rack .tile')).toHaveCount(7);
+
+    // Opening the history reveals NO social controls on the seat plaques (a local game is
+    // account-less), and the Dictionary entry (the comms button) is kept for the active game.
+    await page.locator('.scoreboard').click();
+    await expect(page.locator('.fico')).toHaveCount(0);
+    await expect(page.locator('.chat-ico')).toBeVisible();
+    await page.locator('.scoreboard').click();
+
+    // Host override: 🔐 -> master PIN -> skip the current turn -> confirm. The turn passes to Bob,
+    // whose seat is open, so his rack shows without a lock.
+    await page.locator('button.tab', { hasText: /Host|Ведущий/ }).click();
+    await typePin(page, '9999');
+    await page.getByRole('button', { name: /Skip|Пропустить/ }).click();
+    await page.getByRole('button', { name: /^(OK|ОК)$/ }).click();
+    await expect(page.locator('.unlock')).toHaveCount(0);
+    await expect(page.locator('.rack .tile')).toHaveCount(7);
+
+    // Back in the lobby the active hotseat game has a kebab; terminating it needs the master PIN.
+    await page.getByRole('button', { name: /Back|Назад/i }).click();
+    await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible();
+    await expect(page.locator('.rowwrap')).toHaveCount(1);
+    await page.locator('.kebab').first().click();
+    const del = page.locator('.rowwrap.revealed .del');
+    await expect(del).toBeVisible();
+    await del.click();
+    await typePin(page, '9999');
+    await expect(page.locator('.rowwrap')).toHaveCount(0);
+  });
+});

ui/e2e/install.spec.ts

@@ -0,0 +1,59 @@
+import { expect, test } from './fixtures';
+
+// The install CTA (components/InstallApp.svelte) is platform-adaptive: a one-tap button where the
+// browser offers a beforeinstallprompt (Chromium), a manual instructions modal on iOS Safari, and
+// nothing elsewhere / once installed / inside a Mini App. The native OS install dialog is
+// browser-level and not drivable from Playwright, so these assert the CTA's presence and branch.
+
+const IPHONE_SAFARI =
+  'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1';
+
+test('web: a captured install prompt shows the one-tap CTA and clicking it prompts', async ({ page }) => {
+  await page.goto('/');
+  // The web login screen is shown (an ordinary browser tab, not a Mini App).
+  await expect(page.getByRole('button', { name: /guest/i })).toBeVisible();
+
+  // Hidden until the browser offers installation (Playwright never fires beforeinstallprompt).
+  await expect(page.getByRole('button', { name: /Install the app/i })).toHaveCount(0);
+
+  // Simulate Chromium offering the install: dispatch a beforeinstallprompt the app can capture.
+  await page.evaluate(() => {
+    const e = new Event('beforeinstallprompt') as Event & {
+      prompt?: () => Promise<void>;
+      userChoice?: Promise<unknown>;
+    };
+    (window as unknown as { __promptCalled: boolean }).__promptCalled = false;
+    e.prompt = () => {
+      (window as unknown as { __promptCalled: boolean }).__promptCalled = true;
+      return Promise.resolve();
+    };
+    e.userChoice = Promise.resolve({ outcome: 'accepted', platform: '' });
+    window.dispatchEvent(e);
+  });
+
+  const cta = page.getByRole('button', { name: /Install the app/i });
+  await expect(cta).toBeVisible();
+  await cta.click();
+  // Clicking calls the captured prompt (the native dialog itself is not observable here).
+  await expect
+    .poll(() => page.evaluate(() => (window as unknown as { __promptCalled: boolean }).__promptCalled))
+    .toBe(true);
+});
+
+test.describe('iOS Safari', () => {
+  test.use({ userAgent: IPHONE_SAFARI });
+
+  test('shows manual Add-to-Home-Screen instructions (no programmatic install)', async ({ page }) => {
+    await page.goto('/');
+    await expect(page.getByRole('button', { name: /guest/i })).toBeVisible();
+
+    // On iOS Safari the CTA shows at once (no beforeinstallprompt is ever fired there).
+    const cta = page.getByRole('button', { name: /Install the app/i });
+    await expect(cta).toBeVisible();
+    await cta.click();
+
+    // It opens the app's own instructions modal (not a native / Telegram popup).
+    await expect(page.getByRole('heading', { name: 'Add to Home Screen' })).toBeVisible();
+    await expect(page.getByText(/Tap the Share button/)).toBeVisible();
+  });
+});

ui/e2e/landing.spec.ts

@@ -46,3 +46,15 @@ test('the landing is a normal scrolling document (the SPA document-pin does not
   expect(state.shell).toBe(false);
   expect(state.bodyPosition).not.toBe('fixed');
 });
+
+// The web-version entry (/app/) is always present, alongside the build-var-gated Telegram/VK ones
+// (absent here, since e2e sets no VITE_* vars), each with a caption.
+test('the landing shows a web-version entry linking /app/, with a caption', async ({ page }) => {
+  await page.goto('/landing.html');
+  await expect(page.getByText(/Играй в «Эрудита»/)).toBeVisible(); // Russian by default
+
+  const web = page.getByRole('link', { name: 'Играть в браузере' });
+  await expect(web).toBeVisible();
+  expect(await web.getAttribute('href')).toContain('/app/');
+  await expect(page.getByText('Веб-версия')).toBeVisible();
+});

ui/e2e/offline.spec.ts

@@ -0,0 +1,95 @@
+import { test, expect, type Page } from './fixtures';
+
+// The offline mode is gated to an installed standalone PWA with a confirmed email. The mock account
+// has an email; force the standalone display mode so the Settings offline toggle is offered. Only the
+// `(display-mode: standalone)` query is overridden — theme/reduce-motion queries pass through.
+async function forceStandalone(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const orig = window.matchMedia.bind(window);
+    window.matchMedia = (q: string) =>
+      (q.includes('display-mode: standalone')
+        ? { matches: true, media: q, onchange: null, addEventListener() {}, removeEventListener() {}, addListener() {}, removeListener() {}, dispatchEvent: () => false }
+        : orig(q)) as MediaQueryList;
+  });
+}
+
+// After a load, land in the lobby. The mock cold-starts on the login screen (no seeded session), so
+// click through as guest. Waiting for the button (rather than a point-in-time count()) is what makes
+// this deterministic: a count() sampled during the pre-login splash frame returned 0, skipped the
+// click, and then hung — or latched a transient lobby tab-bar — instead of opening the real lobby.
+async function enterLobby(page: Page): Promise<void> {
+  await page.getByRole('button', { name: /guest|гост/i }).first().click();
+  // The lobby tab bar has three tabs in a fixed order: New (0), Stats (1), Settings (2). nth() is
+  // robust to locale, emoji variation selectors and the coachmark anchors (which the first-run
+  // onboarding strips after it completes).
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+// Pick a rack tile by its glyph and drop it on a board square (the rack of the pinned-seed game has
+// all-distinct letters, so the glyph is unambiguous).
+async function placeTile(page: Page, glyph: string, row: number, col: number): Promise<void> {
+  await page.locator('.rack .tile', { hasText: glyph }).first().click();
+  await page.locator(`[data-cell][data-row="${row}"][data-col="${col}"]`).click();
+}
+
+test.describe('offline mode', () => {
+  test('enter via the toggle, play a local vs_ai game, persist across a reload', async ({ page }) => {
+    await forceStandalone(page);
+    await page.goto('/');
+    await enterLobby(page);
+
+    // Online: a seeded online game (vs Ann) is listed.
+    await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible();
+
+    // Enter offline through the real Settings toggle (its readiness check fetches every enabled
+    // variant's dawg, served from /e2edict/ by the mock) — the header turns blue with the chip.
+    await page.locator('button.tab').nth(2).click();
+    await page.getByRole('button', { name: /^(Offline|Оффлайн)$/ }).click();
+    await expect(page.locator('header.nav.offline')).toBeVisible({ timeout: 15000 });
+
+    // Back in the (now offline) lobby: the online games are hidden and the Stats tab is disabled.
+    await page.getByRole('button', { name: /Back|Назад/i }).click();
+    await expect(page.locator('button.tab').nth(2)).toBeVisible();
+    await expect(page.getByText('Ann', { exact: false })).toHaveCount(0);
+    await expect(page.locator('button.tab').nth(1)).toBeDisabled();
+
+    // Create a device-local English vs_ai game with a pinned bag seed (deals the rack NEWYMAO).
+    await page.evaluate(() => (window as unknown as { __mock: { setLocalSeed(s: string): void } }).__mock.setLocalSeed('1'));
+    await page.locator('button.tab').nth(0).click();
+    // The English variant's display name is "Scrabble" (Latin) in both locales — the Russian
+    // variants are "Скрэббл"/"Эрудит"/"Erudite", so this uniquely selects the English game.
+    await page.locator('.variant', { hasText: 'Scrabble' }).click();
+    await page.locator('button.invite').click();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+
+    // The human's first move is not idle-gated: the hint is available at once (no 🔒 lock badge).
+    await expect(page.locator('.lock')).toHaveCount(0);
+
+    // The human plays WAY horizontally across the centre (7,5)-(7,7).
+    await placeTile(page, 'W', 7, 5);
+    await placeTile(page, 'A', 7, 6);
+    await placeTile(page, 'Y', 7, 7);
+    await expect(page.locator('[data-cell].pending')).toHaveCount(3);
+    await page.locator('.make').click();
+
+    // The play commits and the local robot replies with a real move, so the board carries more than
+    // WAY's three tiles.
+    await expect(async () => {
+      expect(await page.locator('[data-cell].filled').count()).toBeGreaterThan(3);
+    }).toPass({ timeout: 15000 });
+    const filled = await page.locator('[data-cell].filled').count();
+
+    // Now it is the human's turn again after the robot moved: the idle hint gate arms, so the hint
+    // button shows the 🔒 lock (it lifts after 30 idle minutes on a monotonic clock — not waited here).
+    await expect(page.locator('.lock')).toBeVisible();
+
+    // Reload: the hash router restores the /game/<id> route and the local game replays from
+    // IndexedDB with every committed tile intact.
+    await page.reload();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+    await expect(page.locator('[data-cell].filled')).toHaveCount(filled);
+    // The idle-hint gate is persisted (a wall-clock unlock time), so the 🔒 survives the reload —
+    // the wait was not reset by relaunching.
+    await expect(page.locator('.lock')).toBeVisible();
+  });
+});

ui/e2e/router.spec.ts

@@ -0,0 +1,26 @@
+import { expect, test } from './fixtures';
+
+// The hash router must update its reactive `route` rune synchronously inside navigate(), not defer it
+// to the asynchronous `hashchange` event. Bootstrap flips `app.ready` in the same tick right after
+// `navigate('/login')` on an unauthenticated cold start; a route that trailed the hash for one frame
+// let App.svelte render the stale route (the empty-hash lobby) under the new login screen — a visible
+// lobby-shell flash plus a doomed games.list. It also made the offline e2e flaky: enterLobby could
+// latch that transient lobby tab-bar instead of clicking through the login screen.
+
+test('navigate updates the reactive route synchronously (no hashchange lag)', async ({ page }) => {
+  await page.goto('/');
+  // The bundle has loaded and installed the mock __router seam once the login screen is up.
+  await expect(page.getByRole('button', { name: /guest/i })).toBeVisible();
+
+  // Read the route in the SAME microtask as the navigate: the fix makes it the new route at once;
+  // the pre-fix code returned the previous route (it waited for the async hashchange).
+  const routeAfterNavigate = await page.evaluate(() => {
+    const r = (window as unknown as { __router: { navigate(p: string): void; route(): string } }).__router;
+    r.navigate('/settings');
+    return r.route();
+  });
+  expect(routeAfterNavigate).toBe('settings');
+
+  // The hash was written too, so a reload/back still resolves the same route.
+  expect(new URL(page.url()).hash).toBe('#/settings');
+});

ui/e2e/social.spec.ts

@@ -327,6 +327,36 @@ test('change email: a free address replaces the current one', async ({ page }) =
   await expect(page.getByText('you@example.com')).toHaveCount(0);
 });
 
+// The add-email confirmation can complete out of band: the recipient taps the one-tap link in the
+// email, which confirms in another browser/session. A backgrounded Mini App misses the live
+// 'profile' event (the stream is single-shot, no replay), so the open code form falls back to
+// polling the profile until the address lands. The mock attaches the email WITHOUT emitting an
+// event, so only the poll can surface it.
+test('add email: an out-of-band confirmation surfaces on the open form via polling', async ({ page }) => {
+  await loginLobby(page);
+  await openProfile(page);
+
+  // Drop the seeded email so the sign-in section offers the add-email flow.
+  await page.evaluate(() => (window as unknown as { __mock: { clearEmail(): void } }).__mock.clearEmail());
+  const emailInput = page.locator('.accounts input[type="email"]');
+  await expect(emailInput).toBeVisible();
+
+  await emailInput.fill('linked@example.com');
+  await page.getByRole('button', { name: 'Send code' }).click();
+  await expect(page.locator('.accounts .codein')).toBeVisible();
+
+  // Confirmed elsewhere via the one-tap link, with no live event delivered: only the poll surfaces it.
+  await page.evaluate(() =>
+    (
+      window as unknown as { __mock: { confirmEmailOutOfBand(email: string): void } }
+    ).__mock.confirmEmailOutOfBand('linked@example.com'),
+  );
+
+  // The confirmed address surfaces as the email row, and the code form is gone.
+  await expect(page.locator('.acctrow').filter({ hasText: 'linked@example.com' })).toBeVisible({ timeout: 10000 });
+  await expect(page.locator('.accounts .codein')).toHaveCount(0);
+});
+
 test('link then unlink Telegram from the sign-in methods', async ({ page }) => {
   await loginLobby(page);
   await openProfile(page);

ui/e2e/viewport.spec.ts

@@ -0,0 +1,69 @@
+import { test, expect, type Page } from './fixtures';
+
+// Playwright's WebKit has no real soft keyboard, so emulate iOS's visual-viewport behaviour: replace
+// window.visualViewport with a controllable fake BEFORE the app boots. The app's syncViewport
+// (app.svelte.ts) reads visualViewport.height/offsetTop and mirrors them into --vvh / --vv-top, which
+// position the pinned app-shell (app.css html.app-shell body). Driving the fake exercises the exact
+// code path the real keyboard triggers on iOS — where the layout viewport does NOT shrink and the
+// visual viewport instead offsets down toward the focused field.
+async function installFakeViewport(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const fake = new EventTarget() as EventTarget & { height: number; offsetTop: number; width: number };
+    fake.height = window.innerHeight;
+    fake.offsetTop = 0;
+    fake.width = window.innerWidth;
+    Object.defineProperty(window, 'visualViewport', { configurable: true, value: fake });
+    (window as unknown as { __vv: typeof fake }).__vv = fake;
+  });
+}
+
+async function setViewport(page: Page, height: number, offsetTop: number): Promise<void> {
+  await page.evaluate(
+    ([h, t]) => {
+      const vv = (window as unknown as { __vv: { height: number; offsetTop: number; dispatchEvent(e: Event): boolean } }).__vv;
+      vv.height = h;
+      vv.offsetTop = t;
+      vv.dispatchEvent(new Event('resize'));
+      vv.dispatchEvent(new Event('scroll'));
+    },
+    [height, offsetTop],
+  );
+}
+
+async function shell(page: Page): Promise<{ vvh: string; top: string; bodyTop: string }> {
+  return page.evaluate(() => ({
+    vvh: getComputedStyle(document.documentElement).getPropertyValue('--vvh').trim(),
+    top: getComputedStyle(document.documentElement).getPropertyValue('--vv-top').trim(),
+    bodyTop: getComputedStyle(document.body).top,
+  }));
+}
+
+test.describe('visual-viewport shell (soft-keyboard alignment)', () => {
+  test('the pinned shell follows the visual viewport height AND offset', async ({ page }) => {
+    await installFakeViewport(page);
+    await page.goto('/');
+    await expect(page.locator('html.app-shell')).toBeAttached();
+    const innerH = await page.evaluate(() => window.innerHeight);
+
+    // Keyboard closed: full height, no offset.
+    await setViewport(page, innerH, 0);
+    let s = await shell(page);
+    expect(s.top).toBe('0px');
+    expect(s.bodyTop).toBe('0px');
+
+    // Keyboard open + iOS offset: the visual viewport shrinks AND offsets down. The pinned shell must
+    // follow BOTH — the body's top must equal the offset (not stay at 0), else the top-anchored
+    // content shows empty space below (the iOS bug this fixes).
+    await setViewport(page, innerH - 300, 180);
+    s = await shell(page);
+    expect(s.vvh).toBe(`${innerH - 300}px`);
+    expect(s.top).toBe('180px');
+    expect(s.bodyTop).toBe('180px');
+
+    // Keyboard closed again: the offset reverts to 0 — no stale shift left behind.
+    await setViewport(page, innerH, 0);
+    s = await shell(page);
+    expect(s.top).toBe('0px');
+    expect(s.bodyTop).toBe('0px');
+  });
+});

ui/index.html

@@ -256,6 +256,18 @@
     <link rel="icon" href="favicon.ico" sizes="32x32" />
     <link rel="icon" type="image/svg+xml" href="favicon.svg" />
     <link rel="apple-touch-icon" href="apple-touch-icon.png" />
+    <!-- PWA installability (web /app/ only): the manifest + a service worker (registered from
+         lib/pwa, web-only) let the app be added to the home screen / desktop. The relative href
+         resolves per serving path; these tags are inert inside the Telegram/VK Mini App webviews,
+         which manage their own chrome. theme-color mirrors the light/dark --bg tokens (app.css). -->
+    <link rel="manifest" href="manifest.webmanifest" />
+    <meta name="theme-color" content="#f3f4f6" media="(prefers-color-scheme: light)" />
+    <meta name="theme-color" content="#0f1115" media="(prefers-color-scheme: dark)" />
+    <meta name="mobile-web-app-capable" content="yes" />
+    <meta name="apple-mobile-web-app-capable" content="yes" />
+    <meta name="apple-mobile-web-app-status-bar-style" content="default" />
+    <meta name="apple-mobile-web-app-title" content="Эрудит" />
+    <meta name="application-name" content="Эрудит" />
   </head>
   <body>
     <div id="app"></div>

ui/package.json

@@ -32,6 +32,10 @@
     "svelte-check": "^4.1.0",
     "typescript": "^5.7.0",
     "vite": "^6.0.0",
-    "vitest": "^3.0.0"
+    "vite-plugin-pwa": "^0.21.2",
+    "vitest": "^3.0.0",
+    "workbox-core": "^7.4.1",
+    "workbox-precaching": "^7.4.1",
+    "workbox-routing": "^7.4.1"
   }
 }

ui/playwright.config.ts

@@ -21,8 +21,11 @@ export default defineConfig({
     // under /app/ and /telegram/): served from the preview root, an absolute base keeps assets at
     // /assets/ so the SPA-fallback also boots a subpath like /telegram/. Base only prefixes asset
     // URLs, so the minified JS under test is identical to the contour's.
+    // After the mock build, copy the real per-variant dawgs into the preview output (dist-e2e) so the
+    // offline spec can play a real local vs_ai game; the files are e2e-only (never committed, never in
+    // the production build). Source: E2E_DICT_DIR (CI: the fetched release; local: the sibling).
     command:
-      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
+      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && node scripts/e2e-dict.mjs && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
     url: 'http://localhost:4173',
     reuseExistingServer: !process.env.CI,
     timeout: 120_000,

ui/public/manifest.webmanifest

@@ -0,0 +1,17 @@
+{
+  "name": "Эрудит (Скрэббл)",
+  "short_name": "Эрудит",
+  "description": "Игра в слова «Эрудит» (Скрэббл): играйте с друзьями, случайным соперником или ИИ-роботом.",
+  "lang": "ru",
+  "dir": "ltr",
+  "start_url": ".",
+  "scope": ".",
+  "display": "standalone",
+  "background_color": "#f3f4f6",
+  "theme_color": "#f3f4f6",
+  "icons": [
+    { "src": "icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" },
+    { "src": "icon-maskable-512.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" }
+  ]
+}

ui/scripts/bundle-size.mjs

@@ -19,10 +19,17 @@ import { join } from 'node:path';
 
 const DIST = 'dist';
 
-// Per-chunk gzip budgets in KB. The app entry was raised to 110 when the local
+// Per-chunk gzip budgets in KB. The app entry was raised to 110 for the local move-preview
-// move-preview wiring landed (the heavy dict subsystem stays in lazy chunks; this
+// wiring, to 112 for the PWA install feature, to 113 for the offline-mode wiring, to 114 for
-// covers the small in-entry game/debug wiring it needs).
+// the offline auto-detect (the cold-start reachability check and the "no connection" dialog live in
-const BUDGET = { app: 110, shared: 30, landing: 5 };
+// the boot path), then to 115 for the vs_ai idle-hint gate — its monotonic clock, lock badge and
+// countdown toast live in the always-loaded game screen (Game.svelte) — and to 120 for the offline
+// pass-and-play (hotseat) mode: the on-screen PIN pad, the creation roster and the in-game host menu
+// live in the always-loaded New Game / Game / Lobby screens (the offline engine and the tiny PIN
+// hashing stay in lazy chunks / are negligible). The heavy parts — the dict loader, the move
+// generator and the preload orchestration — still stay in lazy chunks. Scoped CSS lands in the CSS
+// chunk, not this JS budget.
+const BUDGET = { app: 120, shared: 30, landing: 5 };
 
 // gzipped returns the gzipped byte size of a built asset, or 0 when the reference is not a
 // local file (e.g. the Telegram SDK loaded from a CDN) or is missing.

ui/scripts/e2e-dict.mjs

@@ -0,0 +1,35 @@
+// Copies the real per-variant dictionary DAWGs into the mock e2e preview output (dist-e2e/e2edict/)
+// so the offline spec can create and play a real local vs_ai game (the mock's fetchDict serves these
+// files — see lib/mock/client.ts). The dawgs are NEVER committed and never enter the production
+// build; they live only in the throwaway dist-e2e/ that `vite preview` serves for Playwright.
+//
+// Source directory: E2E_DICT_DIR — in CI the fetched scrabble-dictionary release
+// ($GITHUB_WORKSPACE/dawg); locally it defaults to the sibling scrabble-solver/dawg checkout. A
+// missing source only warns (so the other, dawg-free specs still run); the offline spec then fails
+// with an obvious HTTP 404 from fetchDict.
+
+import { existsSync, mkdirSync, copyFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+const srcDir = process.env.E2E_DICT_DIR ?? '../../scrabble-solver/dawg';
+const outDir = 'dist-e2e/e2edict';
+
+// The app's Variant enum value -> the release dawg file name (matches the movegen/parity mapping).
+const dawgFor = {
+  scrabble_en: 'en_sowpods',
+  scrabble_ru: 'ru_scrabble',
+  erudit_ru: 'ru_erudit',
+};
+
+mkdirSync(outDir, { recursive: true });
+let copied = 0;
+for (const [variant, file] of Object.entries(dawgFor)) {
+  const src = join(srcDir, `${file}.dawg`);
+  if (!existsSync(src)) {
+    console.warn(`e2e-dict: missing ${src} — the offline spec will 404 (set E2E_DICT_DIR)`);
+    continue;
+  }
+  copyFileSync(src, join(outDir, `${variant}.dawg`));
+  copied++;
+}
+console.log(`e2e-dict: copied ${copied}/${Object.keys(dawgFor).length} dawgs from ${srcDir} -> ${outDir}`);

ui/src/App.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { cubicOut } from 'svelte/easing';
-  import { app, bootstrap } from './lib/app.svelte';
+  import { app, bootstrap, resolveOfflinePrompt } from './lib/app.svelte';
   import { router, type RouteName } from './lib/router.svelte';
   import { t } from './lib/i18n/index.svelte';
   import Toast from './components/Toast.svelte';
@@ -136,6 +136,21 @@
 <Coachmark />
 <MaintenanceOverlay />
 
+<!-- Cold-start "no connection" dialog: the reachability check timed out with the network interface
+     reportedly online, so it is ambiguous. The player chooses to go offline (play local vs_ai) or to
+     keep trying to connect. bootstrap awaits this choice (app.offlinePrompt). -->
+{#if app.offlinePrompt}
+  <div class="offprompt" role="dialog" aria-modal="true">
+    <div class="card">
+      <p class="msg">{t('offline.promptTitle')}</p>
+      <div class="acts">
+        <button class="opt primary" onclick={() => resolveOfflinePrompt(true)}>{t('offline.promptYes')}</button>
+        <button class="opt" onclick={() => resolveOfflinePrompt(false)}>{t('offline.promptNo')}</button>
+      </div>
+    </div>
+  </div>
+{/if}
+
 {#if routeIsLobby && !app.splashDone && !app.blocked && !app.bootError && !app.launchError}
   <Splash />
 {/if}
@@ -145,6 +160,49 @@
 {/if}
 
 <style>
+  /* The cold-start "no connection" dialog — a centred card over a scrim, above the splash. */
+  .offprompt {
+    position: fixed;
+    inset: 0;
+    z-index: 100;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    background: rgba(0, 0, 0, 0.5);
+    padding: var(--pad);
+  }
+  .offprompt .card {
+    background: var(--bg-elev);
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    padding: 20px;
+    max-width: 320px;
+    width: 100%;
+    text-align: center;
+  }
+  .offprompt .msg {
+    margin: 0 0 16px;
+    font-size: 1rem;
+    color: var(--text);
+  }
+  .offprompt .acts {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+  }
+  .offprompt .opt {
+    padding: 11px 16px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-size: 0.95rem;
+  }
+  .offprompt .opt.primary {
+    background: var(--accent);
+    color: var(--accent-text);
+    border-color: var(--accent);
+  }
   .splash {
     height: 100%;
     display: grid;

ui/src/Landing.svelte

@@ -80,20 +80,26 @@
   <section class="hero">
     <h1>{about.title}</h1>
     <p class="tagline">{t('landing.tagline')}</p>
-    {#if tgLink || vkLink}
+    <!-- Platform entries: Telegram/VK are gated by their build vars; the web version (/app/) is
-      <div class="entries">
+         always available. A caption under each clarifies what it opens. -->
-        {#if tgLink}
+    <div class="entries">
-          <a class="entry" href={tgLink} target="_blank" rel="noopener noreferrer" aria-label={t('landing.playTelegram')}>
+      {#if tgLink}
-            <img src="telegram-logo.svg" alt="" width="64" height="64" />
+        <a class="entry" href={tgLink} target="_blank" rel="noopener noreferrer" aria-label={t('landing.playTelegram')}>
-          </a>
+          <img src="telegram-logo.svg" alt="" width="64" height="64" />
-        {/if}
+          <span class="caption">{t('landing.captionTelegram')}</span>
-        {#if vkLink}
+        </a>
-          <a class="entry" href={vkLink} target="_blank" rel="noopener noreferrer" aria-label={t('landing.playVK')}>
+      {/if}
-            <img src="vk-logo.svg" alt="" width="64" height="64" />
+      {#if vkLink}
-          </a>
+        <a class="entry" href={vkLink} target="_blank" rel="noopener noreferrer" aria-label={t('landing.playVK')}>
-        {/if}
+          <img src="vk-logo.svg" alt="" width="64" height="64" />
-      </div>
+          <span class="caption">{t('landing.captionVK')}</span>
-    {/if}
+        </a>
+      {/if}
+      <a class="entry" href="/app/" aria-label={t('landing.playWeb')}>
+        <img src="favicon.svg" alt="" width="64" height="64" />
+        <span class="caption">{t('landing.captionWeb')}</span>
+      </a>
+    </div>
   </section>
 
   <section class="info">
@@ -207,8 +213,8 @@
     color: var(--text-muted);
     font-size: 1.05rem;
   }
-  /* The platform entries are just the bigger logos in a row (no button chrome, no captions);
+  /* The platform entries are the bigger logos in a row, each with a short caption below; the
-     each link keeps an aria-label for assistive tech. */
+     link keeps an aria-label for assistive tech. */
   .entries {
     align-self: center;
     display: flex;
@@ -217,6 +223,11 @@
   }
   .entry {
     display: inline-flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 8px;
+    text-decoration: none;
+    color: var(--text);
   }
   .entry img {
     display: block;
@@ -225,6 +236,10 @@
   .entry:hover img {
     transform: scale(1.06);
   }
+  .caption {
+    font-size: 0.9rem;
+    color: var(--text-muted);
+  }
   .info {
     background: var(--surface-2);
     border-radius: var(--radius-sm);

ui/src/app.css

@@ -162,7 +162,15 @@ html.app-shell {
 }
 html.app-shell body {
   position: fixed;
-  inset: 0;
+  /* Follow the visual viewport (top + height), not merely fill the layout viewport: iOS Safari /
+     WKWebView does not shrink the layout viewport for the soft keyboard — it offsets the visual
+     viewport down toward the focused field — so a top-anchored (inset:0) shell would misalign, showing
+     empty space below the content (worst on a repeat focus). --vv-top / --vvh are kept in sync from
+     app.svelte.ts (syncViewport). The fallbacks equal inset:0 before the first sync / on the landing. */
+  top: var(--vv-top, 0px);
+  left: 0;
+  right: 0;
+  height: var(--vvh, 100%);
   overflow: hidden;
 }
 

ui/src/components/AdBanner.svelte

@@ -3,12 +3,14 @@
   import {
     attachBannerHost,
     bannerCurrent,
+    bannerCurrentColors,
     configureBanner,
     detachBannerHost,
     remeasureBanner,
   } from '../lib/bannerEngine';
   import { defaultBannerTimings, linkify, type BannerHost } from '../lib/banner';
-  import type { BannerCampaign, BannerTimings } from '../lib/model';
+  import { resolveBannerColors, type ThemeMode } from '../lib/bannerColors';
+  import type { BannerCampaign, BannerColors, BannerTimings } from '../lib/model';
   import { onExternalLinkClick } from '../lib/links';
 
   let {
@@ -21,12 +23,33 @@
   // current message and is visible at once (no fade — see inFade), so a screen change does not
   // replay the fade. Empty on the very first mount (engine not yet started).
   let current = $state(bannerCurrent());
+  let currentColors = $state<BannerColors>(bannerCurrentColors());
   let visible = $state(bannerCurrent() !== '');
   let tx = $state(0);
   let txDur = $state(0);
   let track = $state<HTMLElement>();
   let viewport = $state<HTMLElement>();
 
+  // The rendered theme (light/dark), tracked so a campaign's colour override resolves against the
+  // theme actually on screen and re-resolves live when the operator/OS flips it. It follows the
+  // [data-theme] attribute (theme.ts), or the OS preference when unset ('auto').
+  let themeMode = $state<ThemeMode>(resolveThemeMode());
+  function resolveThemeMode(): ThemeMode {
+    if (typeof document === 'undefined') return 'light';
+    const attr = document.documentElement.getAttribute('data-theme');
+    if (attr === 'dark' || attr === 'light') return attr;
+    return window.matchMedia?.('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+  }
+
+  // The strip's colours for the current campaign + theme (null = the neutral tokens). Applied as
+  // inline CSS variables scoped to .ad, so an override never leaks to the rest of the page.
+  const adColors = $derived(resolveBannerColors(currentColors, themeMode));
+  const adStyle = $derived(
+    adColors
+      ? `--ad-bg:${adColors.bg};--text-muted:${adColors.fg};--accent:${adColors.link};--ad-border:${adColors.border}`
+      : '',
+  );
+
   // The first appearance after mounting onto an already-running cycle is instant; every later
   // message change fades. (Consumed by the first in:fade.)
   let instantOnce = bannerCurrent() !== '';
@@ -50,8 +73,9 @@
   // The DOM host the engine drives. The fade lives on the {#if} layer (transition:fade), the scroll
   // on the inner track's transform, so a long message's scroll never blocks its fade in/out.
   const host: BannerHost = {
-    show(md) {
+    show(md, colors) {
       current = md;
+      currentColors = colors;
       tx = 0;
       txDur = 0;
       visible = true;
@@ -93,6 +117,20 @@
   $effect(() => {
     configureBanner(campaigns, eff);
   });
+  // Track the rendered theme so a colour override re-resolves when the theme flips: watch the
+  // [data-theme] attribute (Settings toggle / Telegram) and, for 'auto', the OS colour scheme.
+  $effect(() => {
+    const update = () => (themeMode = resolveThemeMode());
+    update();
+    const obs = new MutationObserver(update);
+    obs.observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] });
+    const mq = window.matchMedia?.('(prefers-color-scheme: dark)');
+    mq?.addEventListener('change', update);
+    return () => {
+      obs.disconnect();
+      mq?.removeEventListener('change', update);
+    };
+  });
   // Re-measure on a viewport size change (e.g. a portrait↔landscape rotation): a message that fit
   // may now overflow, or vice versa, so the scroll must be re-evaluated. Debounced.
   $effect(() => {
@@ -116,7 +154,7 @@
      confirmation, the VK away-redirect keeps the Android WebView on the game. -->
 <!-- svelte-ignore a11y_no_static_element_interactions -->
 <!-- svelte-ignore a11y_click_events_have_key_events -->
-<div class="ad" bind:this={viewport} onclick={onExternalLinkClick}>
+<div class="ad" bind:this={viewport} style={adStyle} onclick={onExternalLinkClick}>
   <!-- An always-present, invisible spacer reserves exactly one line of height, so the strip never
        collapses while the message layer is absent during the fade gap (the message is overlaid
        absolutely, so its presence/absence does not change the strip height). -->
@@ -145,8 +183,8 @@
     font-size: 0.85rem;
     line-height: 1.2;
     box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.18);
-    border-top: 1px solid var(--border);
+    border-top: 1px solid var(--ad-border, var(--border));
-    border-bottom: 1px solid var(--border);
+    border-bottom: 1px solid var(--ad-border, var(--border));
     user-select: none;
   }
   /* Reserves one line of height inside the padding so .ad keeps a constant height even during the

ui/src/components/Header.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { navigate } from '../lib/router.svelte';
   import { connection } from '../lib/connection.svelte';
+  import { offlineMode, dictPreloadWarning } from '../lib/offline.svelte';
   import { t } from '../lib/i18n/index.svelte';
   import { app, openDebug } from '../lib/app.svelte';
   import Spinner from './Spinner.svelte';
@@ -27,7 +28,7 @@
   }
 </script>
 
-<header class="nav" class:grow>
+<header class="nav" class:grow class:offline={offlineMode.active}>
   <div class="bar">
     {#if showBack}
       <button class="icon back" onclick={() => back && navigate(back)} aria-label="Back">
@@ -36,15 +37,20 @@
     {:else}
       <span class="spacer"></span>
     {/if}
-    {#if connection.online}
+    {#if connection.online || offlineMode.active}
       <!-- svelte-ignore a11y_click_events_have_key_events -->
       <!-- svelte-ignore a11y_no_noninteractive_element_interactions -->
       <h1 onclick={onTitleTap}>{title}</h1>
     {:else}
       <h1 class="connecting"><Spinner /> <span>{t('connection.connecting')}</span></h1>
     {/if}
-    <!-- A right-hand spacer balances the back button so the title stays centred. -->
+    <!-- A right-hand spacer balances the back button so the title stays centred; in offline mode it
-    <span class="spacer"></span>
+         carries the "Offline" chip so the deliberate mode is always visible (not just the blue tint). -->
+    {#if offlineMode.active}
+      <span class="chip">{t('settings.offline')}</span>
+    {:else}
+      <span class="spacer"></span>
+    {/if}
   </div>
   <!-- The ad banner lives inside the nav, directly under the title bar, so it sits in the
        same place on every screen — and in the game (grown nav) the spare height falls below
@@ -52,7 +58,11 @@
        coachmark overlay is up (app.coachActive) so the scrolling strip does not run behind the
        dimmed onboarding layer; the engine keeps rotating (module scope) and the strip reappears,
        per this same condition, once onboarding closes. -->
-  {#if app.profile?.banner && app.profile.banner.campaigns.length && !app.coachActive}
+  {#if dictPreloadWarning.active}
+    <!-- A background dictionary preload for offline readiness failed (poor connection): a soft
+         notice takes the ad banner's slot until a later preload succeeds and clears it. -->
+    <p class="preload-warn" role="alert">{t('offline.preloadWarning')}</p>
+  {:else if app.profile?.banner && app.profile.banner.campaigns.length && !app.coachActive}
     <AdBanner
       campaigns={app.profile.banner.campaigns}
       timings={app.profile.banner.timings}
@@ -74,6 +84,12 @@
     user-select: none;
     -webkit-user-select: none;
   }
+  /* Deliberate offline mode: a blue-tinted nav, mixed from the accent so it tracks the light/dark
+     theme (and any Telegram theme override) — the offline state is unmistakable at a glance. */
+  .nav.offline {
+    background: color-mix(in srgb, var(--accent) 20%, var(--bg-elev));
+    border-bottom-color: color-mix(in srgb, var(--accent) 35%, var(--border));
+  }
   .nav.grow {
     /* Grow into spare height (banner under the title, the board pinned to the bottom), but
        never shrink: on a short viewport the banner keeps its height and the board's own
@@ -114,6 +130,34 @@
     align-items: center;
     justify-content: center;
   }
+  /* The offline chip: a compact accent-tinted pill in the header's right slot. */
+  .chip {
+    min-width: 40px;
+    height: 24px;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0 8px;
+    font-size: 0.72rem;
+    font-weight: 600;
+    color: var(--accent);
+    background: color-mix(in srgb, var(--accent) 16%, transparent);
+    border: 1px solid color-mix(in srgb, var(--accent) 45%, transparent);
+    border-radius: 999px;
+    white-space: nowrap;
+  }
+  /* The offline-readiness preload warning: a soft, muted strip in the ad banner's slot, sized like
+     the banner region so the bar does not jump when it appears. */
+  .preload-warn {
+    margin: 0;
+    padding: 7px var(--pad);
+    font-size: 0.78rem;
+    line-height: 1.3;
+    text-align: center;
+    color: var(--text-muted);
+    background: var(--surface-2);
+    border-top: 1px solid var(--border);
+  }
   .back {
     background: none;
     border: none;

ui/src/components/InstallApp.svelte

@@ -0,0 +1,85 @@
+<script lang="ts">
+  import { t } from '../lib/i18n/index.svelte';
+  import { installMode, promptInstall } from '../lib/pwa.svelte';
+  import Modal from './Modal.svelte';
+
+  // Platform-adaptive: 'oneTap' fires the native Chromium install dialog; 'iosInstructions' opens
+  // the manual Share -> Add-to-Home-Screen guide (iOS Safari has no programmatic install); 'hidden'
+  // renders nothing (already installed, inside a Telegram/VK Mini App, or an unsupported browser).
+  const mode = $derived(installMode());
+  let showIos = $state(false);
+
+  function onClick(): void {
+    // promptInstall must run synchronously from this gesture — the deferred prompt is gated on it.
+    if (mode === 'oneTap') void promptInstall();
+    else if (mode === 'iosInstructions') showIos = true;
+  }
+</script>
+
+{#if mode !== 'hidden'}
+  <button type="button" class="install" onclick={onClick}>
+    <img src="favicon.svg" alt="" width="40" height="40" />
+    <span class="text">
+      <span class="title">{t('install.title')}</span>
+      <span class="subtitle">{t('install.subtitle')}</span>
+    </span>
+  </button>
+{/if}
+
+{#if showIos}
+  <Modal title={t('install.iosTitle')} onclose={() => (showIos = false)}>
+    <ol class="steps">
+      <li>{t('install.iosStep1')}</li>
+      <li>{t('install.iosStep2')}</li>
+      <li>{t('install.iosStep3')}</li>
+    </ol>
+    <button type="button" class="ok" onclick={() => (showIos = false)}>{t('common.ok')}</button>
+  </Modal>
+{/if}
+
+<style>
+  .install {
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    width: 100%;
+    text-align: left;
+    padding: 12px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    cursor: pointer;
+  }
+  .install img {
+    flex: none;
+    border-radius: 8px;
+  }
+  .text {
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+    min-width: 0;
+  }
+  .title {
+    font-weight: 600;
+  }
+  .subtitle {
+    font-size: 0.85rem;
+    color: var(--text-muted);
+    line-height: 1.35;
+  }
+  .steps {
+    margin: 0 0 16px;
+    padding-left: 1.25rem;
+    line-height: 1.6;
+  }
+  .ok {
+    width: 100%;
+    padding: 10px 12px;
+    border: 1px solid var(--accent);
+    background: var(--accent);
+    color: var(--accent-text);
+    border-radius: var(--radius-sm);
+  }
+</style>

ui/src/components/PinPad.svelte

@@ -0,0 +1,268 @@
+<script lang="ts">
+  // Apple-lock-screen-style 4-digit PIN pad for offline pass-and-play (hotseat) games.
+  // Modes:
+  //   set     — enter a PIN, then repeat it to confirm; emits { kind: 'set', lock }.
+  //   verify  — enter a PIN; runs `verify(pin)` on the 4th digit; emits { kind: 'verified' }
+  //             or shakes + clears on a wrong PIN.
+  //   change  — run `verify` on the current PIN, then offer "set a new PIN" (the set flow)
+  //             or, when allowRemove, "remove PIN" ({ kind: 'removed' }).
+  // Verification is delegated to the caller's `verify` callback: at creation time it checks a
+  // UI-held lock (lib/pin verifyPin); in-game it delegates to the local source (which holds the
+  // stored lock). The pad never shows an OK button: entering the 4th digit is the action. PIN
+  // storage is a social lock, not cryptography — see lib/pin.ts.
+  import Modal from './Modal.svelte';
+  import { t } from '../lib/i18n/index.svelte';
+  import { newLock, type PinLock } from '../lib/pin';
+
+  /** PinResult is the outcome handed to onresult when the pad completes. */
+  export type PinResult =
+    | { kind: 'set'; lock: PinLock }
+    | { kind: 'verified' }
+    | { kind: 'removed' };
+
+  let {
+    mode,
+    title = '',
+    verify,
+    allowRemove = false,
+    onclose,
+    onresult,
+  }: {
+    mode: 'set' | 'verify' | 'change';
+    title?: string;
+    /** Verifies an entered PIN (required for 'verify' and 'change'). */
+    verify?: (pin: string) => Promise<boolean>;
+    allowRemove?: boolean;
+    onclose?: () => void;
+    onresult: (r: PinResult) => void;
+  } = $props();
+
+  const LEN = 4;
+
+  // 'old' verifies the existing PIN (change); 'menu' offers set-new / remove (change);
+  // 'enter' collects a PIN; 'confirm' re-enters it (set / change→new). `mode` is fixed
+  // for the pad's lifetime (callers mount a fresh pad per operation), so capturing its
+  // initial value here is intentional.
+  // svelte-ignore state_referenced_locally
+  let phase = $state<'old' | 'menu' | 'enter' | 'confirm'>(mode === 'change' ? 'old' : 'enter');
+  let buffer = $state('');
+  let first = $state(''); // the first entry, awaiting confirmation
+  let error = $state(false); // drives the error prompt + shake
+  let shakeSeq = $state(0); // bumped on each error to replay the shake animation
+  let busy = $state(false); // guards the async check between the 4th digit and the outcome
+
+  function promptText(): string {
+    if (error) return phase === 'confirm' ? t('pin.mismatch') : t('pin.wrong');
+    switch (phase) {
+      case 'old':
+        return t('pin.enterCurrent');
+      case 'confirm':
+        return t('pin.repeat');
+      default:
+        return mode === 'verify' ? t('pin.enter') : t('pin.create');
+    }
+  }
+
+  function fail(): void {
+    buffer = '';
+    error = true;
+    shakeSeq += 1;
+  }
+
+  async function commit(): Promise<void> {
+    busy = true;
+    try {
+      // Let the 4th dot register before the verdict: a beat so the fill (and, on failure, the shake)
+      // reads as a deliberate response rather than an instant flicker.
+      await new Promise((r) => setTimeout(r, 250));
+      if (phase === 'old') {
+        if (verify && (await verify(buffer))) {
+          buffer = '';
+          error = false;
+          phase = 'menu';
+        } else fail();
+      } else if (phase === 'enter' && mode === 'verify') {
+        if (verify && (await verify(buffer))) onresult({ kind: 'verified' });
+        else fail();
+      } else if (phase === 'enter') {
+        first = buffer;
+        buffer = '';
+        error = false;
+        phase = 'confirm';
+      } else if (phase === 'confirm') {
+        if (buffer === first) onresult({ kind: 'set', lock: await newLock(buffer) });
+        else {
+          first = '';
+          phase = 'enter';
+          fail();
+        }
+      }
+    } finally {
+      busy = false;
+    }
+  }
+
+  function press(d: string): void {
+    if (busy || phase === 'menu' || buffer.length >= LEN) return;
+    error = false;
+    buffer += d;
+    if (buffer.length === LEN) void commit();
+  }
+
+  function back(): void {
+    if (busy || phase === 'menu') return;
+    buffer = buffer.slice(0, -1);
+  }
+
+  function startNew(): void {
+    error = false;
+    first = '';
+    buffer = '';
+    phase = 'enter';
+  }
+
+  function onkey(e: KeyboardEvent): void {
+    if (e.key >= '0' && e.key <= '9') {
+      press(e.key);
+      e.preventDefault();
+    } else if (e.key === 'Backspace') {
+      back();
+      e.preventDefault();
+    } else if (e.key === 'Escape') {
+      onclose?.();
+    }
+  }
+
+  const keys = ['1', '2', '3', '4', '5', '6', '7', '8', '9'];
+  const slots = Array.from({ length: LEN }, (_, i) => i);
+</script>
+
+<svelte:window onkeydown={onkey} />
+
+<Modal {title} {onclose} overlayKeyboard>
+  <div class="pad">
+    {#if phase === 'menu'}
+      <div class="menu">
+        <button class="opt" onclick={startNew}>{t('pin.setNew')}</button>
+        {#if allowRemove}
+          <button class="opt danger" onclick={() => onresult({ kind: 'removed' })}>
+            {t('pin.remove')}
+          </button>
+        {/if}
+      </div>
+    {:else}
+      <p class="prompt" class:err={error}>{promptText()}</p>
+      {#key shakeSeq}
+        <div class="dots" class:shake={error} aria-hidden="true">
+          {#each slots as i}
+            <span class="dot" class:on={i < buffer.length}></span>
+          {/each}
+        </div>
+      {/key}
+      <div class="grid">
+        {#each keys as k}
+          <button class="key" onclick={() => press(k)} aria-label={k}>{k}</button>
+        {/each}
+        <span class="key spacer"></span>
+        <button class="key" onclick={() => press('0')} aria-label="0">0</button>
+        <button class="key back" onclick={back} aria-label="⌫" disabled={buffer.length === 0}>⌫</button>
+      </div>
+    {/if}
+  </div>
+</Modal>
+
+<style>
+  .pad {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 16px;
+    padding-top: 4px;
+  }
+  .prompt {
+    margin: 0;
+    font-size: 0.95rem;
+    color: var(--muted, var(--text));
+    min-height: 1.2em;
+  }
+  .prompt.err {
+    color: var(--danger);
+  }
+  .dots {
+    display: flex;
+    gap: 16px;
+  }
+  .dot {
+    width: 14px;
+    height: 14px;
+    border-radius: 50%;
+    border: 1.5px solid var(--text);
+    box-sizing: border-box;
+  }
+  .dot.on {
+    background: var(--text);
+  }
+  .shake {
+    animation: shake 0.32s ease;
+  }
+  @keyframes shake {
+    0%, 100% { transform: translateX(0); }
+    20% { transform: translateX(-7px); }
+    40% { transform: translateX(7px); }
+    60% { transform: translateX(-5px); }
+    80% { transform: translateX(5px); }
+  }
+  .grid {
+    display: grid;
+    grid-template-columns: repeat(3, 1fr);
+    gap: 12px;
+  }
+  .key {
+    width: 62px;
+    height: 62px;
+    border-radius: 50%;
+    border: 1px solid var(--border);
+    background: var(--surface);
+    color: var(--text);
+    font-size: 1.4rem;
+    font-weight: 500;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+  }
+  .key:active {
+    background: var(--accent);
+    color: var(--accent-text);
+  }
+  .key.back {
+    border-color: transparent;
+    background: transparent;
+    font-size: 1.2rem;
+  }
+  .key.back:disabled {
+    opacity: 0.3;
+  }
+  .key.spacer {
+    border: none;
+    background: none;
+    pointer-events: none;
+  }
+  .menu {
+    display: flex;
+    flex-direction: column;
+    gap: 10px;
+    width: 100%;
+  }
+  .opt {
+    padding: 14px;
+    border: 1px solid var(--border);
+    background: var(--surface);
+    color: var(--text);
+    border-radius: var(--radius);
+    font-weight: 600;
+  }
+  .opt.danger {
+    border-color: var(--danger);
+    color: var(--danger);
+  }
+</style>

ui/src/components/Toast.svelte

@@ -3,8 +3,9 @@
   import { app, dismissToast } from '../lib/app.svelte';
 
   const dur = $derived(app.reduceMotion ? 0 : 260);
-  // An info bubble owns its whole 2s life through a CSS rise-and-fade animation, so it takes
+  // An info bubble owns its whole 3s life through a CSS animation — appear, a ~1s hold at rest,
-  // no Svelte enter/leave transition; an error keeps the fly-in / fade-out dwell behaviour.
+  // then rise-and-fade — so it takes no Svelte enter/leave transition; an error keeps the fly-in /
+  // fade-out dwell behaviour.
   const isInfo = $derived(app.toast?.kind !== 'error');
 </script>
 
@@ -50,17 +51,19 @@
     border-color: var(--danger);
     color: var(--danger);
   }
-  /* An info bubble fades in, then drifts up by roughly the tab-bar height while fading out,
+  /* An info bubble fades in, holds for ~1s at rest, then drifts up by roughly the tab-bar height
-     all within 2s; the X centring is preserved across the rise. */
+     while fading out, all within 3s; the X centring is preserved across the rise. The 8%/41%
+     stops are the appear (~240ms) and the end of the ~1s hold. */
   .toast.rise {
-    animation: toast-rise 2s ease-out forwards;
+    animation: toast-rise 3s ease-out forwards;
   }
   @keyframes toast-rise {
     0% {
       opacity: 0;
       transform: translateX(-50%) translateY(8px);
     }
-    12% {
+    8%,
+    41% {
       opacity: 1;
       transform: translateX(-50%) translateY(0);
     }
@@ -69,16 +72,16 @@
       transform: translateX(-50%) translateY(-56px);
     }
   }
-  /* Reduced motion: the same 2s life, fade only — no upward travel. */
+  /* Reduced motion: the same 3s life (appear, ~1s hold, fade), fade only — no upward travel. */
   .toast.rise-reduced {
-    animation: toast-rise-reduced 2s ease-out forwards;
+    animation: toast-rise-reduced 3s ease-out forwards;
   }
   @keyframes toast-rise-reduced {
     0% {
       opacity: 0;
     }
-    12%,
+    8%,
-    70% {
+    41% {
       opacity: 1;
     }
     100% {

ui/src/game/CheckScreen.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { gateway } from '../lib/gateway';
+  import { gameSource, isLocalGameId } from '../lib/gamesource';
   import { handleError, showToast } from '../lib/app.svelte';
   import { t } from '../lib/i18n/index.svelte';
   import { alphabetLetters } from '../lib/alphabet';
@@ -20,8 +21,10 @@
 
   onMount(async () => {
     try {
-      // Include the alphabet so input sanitising + the check accept the variant's letters.
+      // Include the alphabet so input sanitising + the check accept the variant's letters. Routed
-      const st = await gateway.gameState(id, true);
+      // through gameSource so an offline (local) game resolves its state from the device, not the
+      // network.
+      const st = await gameSource(id).gameState(id, true);
       variant = st.game.variant;
     } catch (e) {
       handleError(e);
@@ -41,7 +44,7 @@
     cooling = true;
     setTimeout(() => (cooling = false), 5000);
     try {
-      const r = await gateway.checkWord(id, w, variant);
+      const r = await gameSource(id).checkWord(id, w, variant);
       checked.set(w, r.legal);
       result = { word: w, legal: r.legal };
     } catch (e) {
@@ -77,7 +80,11 @@
         : t('game.wordIllegal', { word: result.word })}
     </p>
     <div class="actions">
-      <button class="complain" onclick={complain}>{t('game.complain')}</button>
+      <!-- Complaints go to the admin over the network; a local (offline) game has no backend to
+           receive them, so the control is dropped there. -->
+      {#if !isLocalGameId(id)}
+        <button class="complain" onclick={complain}>{t('game.complain')}</button>
+      {/if}
       {#if result.legal}
         <a
           class="lookup"

ui/src/game/CommsHub.svelte

@@ -16,15 +16,21 @@
   // The game is rendered (and cached) before its comms open, so the cache tells us whether
   // it is still active without another fetch; an unknown game keeps the Dictionary offered.
   const active = $derived(getCachedGame(id)?.view.game.status !== 'finished');
-  // An honest-AI game has no chat at all, so its hub is Dictionary-only.
+  // A local game has NO chat: an honest-AI game (vs_ai) and an offline pass-and-play (hotseat) game.
-  const vsAi = $derived(getCachedGame(id)?.view.game.vsAi ?? false);
+  // Its hub is Dictionary-only.
+  const chatless = $derived(
+    (getCachedGame(id)?.view.game.vsAi ?? false) || (getCachedGame(id)?.view.game.hotseat ?? false),
+  );
   // Seeded once from the entry route's tab, then owned locally. The effect keeps the tab valid:
-  // an AI game has only the Dictionary; a finished non-AI game has only Chat (a stale Dictionary
+  // a chatless game has only the Dictionary; a finished non-AI game has only Chat (a stale Dictionary
   // deep-link falls back to Chat).
+  // A chatless game starts on the Dictionary regardless of the entry route — this keeps ChatScreen
+  // (which fetches chat over the network) from mounting even for a beat, which would otherwise raise
+  // an error toast in offline mode.
   // svelte-ignore state_referenced_locally
-  let tab = $state<CommsTab>(initialTab);
+  let tab = $state<CommsTab>(chatless ? 'dictionary' : initialTab);
   $effect(() => {
-    if (vsAi) tab = 'dictionary';
+    if (chatless) tab = 'dictionary';
     else if (tab === 'dictionary' && !active) tab = 'chat';
   });
 </script>
@@ -43,7 +49,7 @@
 
   {#snippet tabbar()}
     <TabBar>
-      {#if !vsAi}
+      {#if !chatless}
         <button class="tab" class:active={tab === 'chat'} onclick={() => (tab = 'chat')}>
           <span class="face"><span class="sq" aria-hidden="true">💬</span><span class="lbl">{t('game.chat')}</span></span>
         </button>

ui/src/game/Game.svelte

@@ -4,24 +4,28 @@
   import TabBar from '../components/TabBar.svelte';
   import TapConfirm from '../components/TapConfirm.svelte';
   import Modal from '../components/Modal.svelte';
+  import PinPad from '../components/PinPad.svelte';
   import DictWarmup from '../components/DictWarmup.svelte';
   import Board from './Board.svelte';
   import Rack from './Rack.svelte';
   import { gateway } from '../lib/gateway';
+  import { gameSource, localSource, isLocalGameId } from '../lib/gamesource';
   import { notePreviewLocal, notePreviewNetwork } from '../lib/localeval-metrics';
   import { navigate } from '../lib/router.svelte';
   import { app, handleError, showToast, markChatRead, seedChatUnread } from '../lib/app.svelte';
   import { connection } from '../lib/connection.svelte';
+  import { offlineMode } from '../lib/offline.svelte';
   import { GatewayError } from '../lib/client';
   import { t, type MessageKey } from '../lib/i18n/index.svelte';
   import type { EvalResult, MoveRecord, MoveResult, StateView, Tile } from '../lib/model';
   import { lastMoveCells, replay } from '../lib/board';
   import { badgeKind } from '../lib/unread';
+  import { seatMedal } from '../lib/result';
   import { historyGrid } from '../lib/history';
   import { centre, premiumGrid } from '../lib/premiums';
   import { variantNameKey, usesStarBlank, BLANK_STAR } from '../lib/variants';
   import { alphabetLetters, hasAlphabet } from '../lib/alphabet';
-  import { hintsLeft } from '../lib/hints';
+  import { hintsLeft, hintGateRemainingMs, hintLockMinutes, HINT_GATE_MS } from '../lib/hints';
   import { downloadUrl, shareOrDownloadGcg, shareUrlAsFile } from '../lib/share';
   import { insideVK, vkAndroidWebView, vkCopyText, vkDownloadFile, vkPlatform, vkShowImages } from '../lib/vk';
   import { getCachedGame, setCachedGame, setCachedDraft, type CachedGame } from '../lib/gamecache';
@@ -47,6 +51,18 @@
 
   let { id }: { id: string } = $props();
 
+  // The game's source: the local engine for an offline game id, otherwise the network gateway. The
+  // screen calls the game-loop methods (state/history/submit/pass/exchange/resign/hint/evaluate/
+  // draft) through it, so the same UI drives a local vs_ai game and an online one alike.
+  const source = $derived(gameSource(id));
+  // A local (offline) game plays entirely on-device, so it is always ready; an online game needs a
+  // live connection — and offline mode's kill switch refuses its calls — so its network actions are
+  // disabled while disconnected or in offline mode (which also stops the "something went wrong"
+  // toasts a blocked call would otherwise raise).
+  const netReady = $derived(isLocalGameId(id) || (connection.online && !offlineMode.active));
+  // Unsubscribes from a local game's robot-reply events (offline only; null for a network game).
+  let localUnsub: (() => void) | null = null;
+
   let view = $state<StateView | null>(null);
   let moves = $state<MoveRecord[]>([]);
   let placement = $state<Placement>(newPlacement([]));
@@ -149,10 +165,42 @@
   const playable = $derived(!!view && (view.game.status === 'active' || view.game.status === 'open'));
   const isMyTurn = $derived(!!view && playable && view.game.toMove === view.seat);
   const gameOver = $derived(!!view && view.game.status === 'finished');
+  // Offline hotseat: the seat to move is PIN-locked until its owner enters the seat PIN this turn.
+  // While locked the board stays visible but the rack is withheld and the move controls disabled;
+  // canMove folds the lock into isMyTurn (locked is always false for a network / vs_ai game).
+  const locked = $derived(!!view?.locked);
+  const canMove = $derived(isMyTurn && !locked);
   // The hint badge: this game's allowance remaining plus the LIVE global wallet. Reading the
   // wallet from the profile (not the per-game view snapshot) keeps it correct after a wallet
   // hint was spent in another game (see lib/hints).
   const hintCount = $derived(hintsLeft(view, app.profile?.hintBalance ?? 0));
+  // A vs_ai game's hint is unlimited and wallet-free, but idle-gated (an anti-frustration aid: it
+  // unlocks only after the player has been stuck ~30 min on a turn). The source (the SERVER clock
+  // online, the device clock offline) tells us the SECONDS LEFT (view.hintUnlockLeftSeconds); we
+  // anchor a MONOTONIC countdown (performance.now()) to it, so a client clock change cannot skew it.
+  // A fresh value arrives on load (armHintGate below); when the robot moves the wait is the full
+  // window. `monoNow` ticks so the 🔒 lifts live at the mark.
+  let hintGateStart = $state<number | null>(null); // performance.now() at the last anchor; null = open
+  let gateLeftMs = $state(0);
+  let monoNow = $state(performance.now());
+  const hintRemaining = $derived(hintGateRemainingMs(hintGateStart, gateLeftMs, monoNow));
+  const hintGated = $derived(hintRemaining > 0);
+  // Anchor the countdown to a freshly received seconds-left (or open the gate). Called on every state
+  // load from the view, and on the robot's move to the full window (the robot just moved).
+  function armHintGate(leftSeconds: number): void {
+    if (leftSeconds > 0) {
+      hintGateStart = performance.now();
+      gateLeftMs = leftSeconds * 1000;
+    } else {
+      hintGateStart = null;
+      gateLeftMs = 0;
+    }
+  }
+  $effect(() => {
+    if (!view?.game.vsAi) return;
+    const iv = setInterval(() => (monoNow = performance.now()), 10_000);
+    return () => clearInterval(iv);
+  });
   // RACK_SIZE mirrors the engine's rules.RackSize (7 for every current variant). The exchange
   // gate is only a UX guard: the backend stays the source of truth and rejects an under-supplied
   // exchange regardless (engine rejects when bag.Len() < rules.RackSize).
@@ -190,11 +238,13 @@
       // Fetch the saved draft alongside state and history (best-effort) so the composition is
       // applied in the same tick the board appears — never as a second, visible rack→board step.
       const [st, hist, draft] = await Promise.all([
-        gateway.gameState(id, includeAlphabet),
+        source.gameState(id, includeAlphabet),
-        gateway.gameHistory(id),
+        source.gameHistory(id),
-        gateway.draftGet(id).catch(() => ''),
+        source.draftGet(id).catch(() => ''),
       ]);
       view = st;
+      // Anchor the vs_ai idle-hint countdown to the freshly fetched seconds-left (0 = open / non-vs_ai).
+      armHintGate(st.game.vsAi ? (st.hintUnlockLeftSeconds ?? 0) : 0);
       syncWallet(st.walletBalance);
       // Seed the unread flag from the authoritative state (the live stream only raises it).
       seedChatUnread(id, st.game.unreadChat, st.game.unreadMessages);
@@ -220,7 +270,7 @@
     setCachedDraft(id, json);
     if (draftSaveTimer) clearTimeout(draftSaveTimer);
     draftSaveTimer = setTimeout(() => {
-      void gateway.draftSave(id, json).catch(() => {});
+      void source.draftSave(id, json).catch(() => {});
     }, 500);
   }
   // applyDraft restores the player's saved composition over a freshly loaded state: the rack
@@ -247,6 +297,9 @@
     if (cached) {
       view = cached.view;
       moves = cached.moves;
+      // Arm the vs_ai idle-hint countdown from the cached seconds-left so the 🔒 shows at once on a
+      // warm open (no wait for load()); the cached value is a snapshot, refreshed by load() below.
+      armHintGate(cached.view.game.vsAi ? (cached.view.hintUnlockLeftSeconds ?? 0) : 0);
       // Apply the cached draft synchronously so a warm/preloaded open paints the pending tiles
       // already on the board (no full-rack-then-jump). load() then refreshes in the background.
       applyDraft(cached.view, cached.draft ?? '');
@@ -264,6 +317,12 @@
         dict = m;
       });
     }
+    // A local (offline) game has no live stream: route the source's robot-reply events through the
+    // same app event hub the network stream feeds, so the event effect above reacts to
+    // opponent_moved / game_over identically.
+    if (isLocalGameId(id)) {
+      localUnsub = localSource.events(id, (e) => (app.lastEvent = e));
+    }
   });
 
   // Warm the game's dictionary for the local move preview once, when both the game and the
@@ -309,7 +368,11 @@
         // While composing, reload so a draft overlapping the new move is reconciled; otherwise apply
         // the move as a delta with no fetch.
         if (placement.pending.length > 0) void load();
-        else applyDelta(applyMoveDelta(cacheSnapshot(), { move: e.move, game: e.game, bagLen: e.bagLen }));
+        else {
+          applyDelta(applyMoveDelta(cacheSnapshot(), { move: e.move, game: e.game, bagLen: e.bagLen }));
+          // The robot just moved (vs_ai) → the human's turn begins with the full idle window.
+          if (view?.game.vsAi) armHintGate(HINT_GATE_MS / 1000);
+        }
       } else if (e.kind === 'your_turn' && e.gameId === id) {
         // The opponent_moved delta carries the new state; your_turn only confirms the turn. Refetch
         // only if we missed the move (our cached count trails the event's).
@@ -611,8 +674,13 @@
     // Flush a pending draft save so leaving mid-composition still persists it.
     if (draftSaveTimer) {
       clearTimeout(draftSaveTimer);
-      void gateway.draftSave(id, serializeDraft(rackIds, placement.pending)).catch(() => {});
+      void source.draftSave(id, serializeDraft(rackIds, placement.pending)).catch(() => {});
     }
+    localUnsub?.();
+    // Leaving a hotseat game re-locks the current seat, so returning from the lobby re-prompts its
+    // PIN. Read the id from the loaded view, NOT the `id` prop: a $props() value reads back undefined
+    // during Svelte teardown, and isLocalGameId(undefined) would throw and abort this cleanup.
+    if (view?.game.hotseat) localSource.relock(view.game.id);
   });
 
   function onCell(row: number, col: number) {
@@ -717,8 +785,8 @@
     // rapid placements do not pile up requests on a slow link.
     evalCtrl?.abort();
     evalCtrl = null;
-    // Off-turn the composition is position-only: no score preview or evaluate.
+    // Off-turn (or a locked hotseat seat) the composition is position-only: no score preview.
-    if (!isMyTurn) return;
+    if (!canMove) return;
     const sub = toSubmit(placement);
     if (!sub) return;
     // Instant on-device preview when the game's dictionary is warm; the network otherwise.
@@ -740,7 +808,7 @@
     evalCtrl = ctrl;
     previewTimer = setTimeout(async () => {
       try {
-        preview = await gateway.evaluate(id, sub.tiles, variant, ctrl.signal);
+        preview = await source.evaluate(id, sub.tiles, variant, ctrl.signal);
         notePreviewNetwork();
       } catch {
         /* best-effort (or aborted) */
@@ -776,12 +844,106 @@
     refreshRecent();
   }
 
+  // --- offline hotseat: seat unlock + host (referee) overrides -------------------
+  let unlockOpen = $state(false); // the current locked seat's owner enters their PIN to reveal the rack
+  // The host menu: 'pin' collects the master PIN, then 'menu' lists the overrides. hostPinEntered is
+  // the verified master PIN, reused to authorise the chosen action (the source re-checks it).
+  let hostMenuStep = $state<'closed' | 'pin' | 'menu'>('closed');
+  let hostPinEntered = $state('');
+  // The pending host action awaiting its confirm ("Skip X's turn?" etc.); null shows the menu list.
+  let hostConfirm = $state<{ action: 'skip' | 'resign' | 'terminate'; seat?: number; name?: string } | null>(null);
+  let hostDone = $state(false); // the transient success ✅ shown after an override
+
+  // hotseatName is the plain display name of a seat by index (hotseat seats are account-less local
+  // players, so no "you"/🤖 resolution is needed — unlike the seat-object seatName used elsewhere).
+  function hotseatName(i: number): string {
+    return view?.game.seats[i]?.displayName ?? '';
+  }
+
+  function startSkip(): void {
+    if (!view) return;
+    hostConfirm = { action: 'skip', seat: view.game.toMove, name: hotseatName(view.game.toMove) };
+  }
+
+  function flashDone(): void {
+    hostDone = true;
+    setTimeout(() => (hostDone = false), 1100);
+  }
+
+  // advanceHotseat re-points the screen at the next seat after a hotseat move: the source has advanced
+  // the turn and re-locked, so a fresh state gives the next seat's rack (empty while it is locked).
+  async function advanceHotseat(): Promise<void> {
+    const st = await source.gameState(id, false);
+    view = st;
+    rackIds = st.rack.map((_, i) => i);
+    placement = newPlacement(st.rack);
+    selected = null;
+    preview = null;
+    setCachedGame(id, st, moves, '');
+  }
+
+  // onUnlock verifies the current seat's PIN through the source (which reveals the rack on success)
+  // and applies the unlocked state; handed to the PIN pad as its verifier.
+  async function onUnlock(pin: string): Promise<boolean> {
+    try {
+      const st = await localSource.unlockSeat(id, pin);
+      view = st;
+      rackIds = st.rack.map((_, i) => i);
+      placement = newPlacement(st.rack);
+      selected = null;
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
+  // verifyHost captures the entered master PIN (reused to authorise the chosen action) and checks it.
+  async function verifyHost(pin: string): Promise<boolean> {
+    hostPinEntered = pin;
+    return localSource.verifyHostPin(id, pin);
+  }
+
+  function hostConfirmText(c: { action: 'skip' | 'resign' | 'terminate'; name?: string }): string {
+    if (c.action === 'skip') return t('hotseat.askSkip', { name: c.name ?? '' });
+    if (c.action === 'resign') return t('hotseat.askExclude', { name: c.name ?? '' });
+    return t('hotseat.askTerminate');
+  }
+
+  async function runHostAction(): Promise<void> {
+    if (!hostConfirm) return;
+    const { action, seat } = hostConfirm;
+    hostConfirm = null;
+    hostMenuStep = 'closed';
+    busy = true;
+    try {
+      const st = await localSource.hostAction(id, hostPinEntered, action, seat);
+      if (st === null) {
+        navigate('/'); // terminated: the game is deleted, so return to the lobby
+        return;
+      }
+      view = st;
+      rackIds = st.rack.map((_, i) => i);
+      placement = newPlacement(st.rack);
+      selected = null;
+      preview = null;
+      moves = (await source.gameHistory(id)).moves; // a skip / resign added a journal move
+      setCachedGame(id, st, moves, '');
+      flashDone();
+    } catch (e) {
+      handleError(e);
+    } finally {
+      busy = false;
+      hostPinEntered = '';
+    }
+  }
+
   async function commit() {
     const sub = toSubmit(placement);
     if (!sub) return;
     busy = true;
     try {
-      applyMoveResult(await gateway.submitPlay(id, sub.tiles, variant));
+      applyMoveResult(await source.submitPlay(id, sub.tiles, variant));
+      if (view?.game.hotseat) await advanceHotseat();
       haptic('success');
       zoomed = false;
     } catch (e) {
@@ -800,7 +962,8 @@
   async function doPass() {
     busy = true;
     try {
-      applyMoveResult(await gateway.pass(id));
+      applyMoveResult(await source.pass(id));
+      if (view?.game.hotseat) await advanceHotseat();
     } catch (e) {
       handleError(e);
     } finally {
@@ -821,7 +984,7 @@
     resignOpen = false;
     busy = true;
     try {
-      applyMoveResult(await gateway.resign(id));
+      applyMoveResult(await source.resign(id));
       // Reveal the final board once the game is resigned: close the move-history drawer
       // (portrait — the landscape dock is unaffected) and zoom out if it was magnified.
       historyOpen = false;
@@ -833,8 +996,17 @@
     }
   }
   async function doHint() {
+    // vs_ai: the idle gate replaces the wallet. While it is still closed, a tap only explains when the
+    // hint unlocks (no wallet is ever spent) — matching the 🔒 badge. Measured fresh at tap time.
+    if (view?.game.vsAi) {
+      const remaining = hintGateRemainingMs(hintGateStart, gateLeftMs, performance.now());
+      if (remaining > 0) {
+        showToast(t('game.hintLockedIn', { n: hintLockMinutes(remaining) }), 'info');
+        return;
+      }
+    }
     try {
-      const h = await gateway.hint(id);
+      const h = await source.hint(id);
       if (h.move.tiles.length && view) {
         placement = placementFromHint(h.move.tiles, view.rack);
         // Scroll the (zoomed) board to the hint's placement rather than the top-left:
@@ -869,6 +1041,12 @@
       // The backend does not spend a hint when there is no move.
       if (e instanceof GatewayError && e.code === 'no_hint_available') {
         showToast(t('game.noHintOptions'), 'info');
+      } else if (e instanceof GatewayError && e.code === 'hint_locked') {
+        // The server-clock backstop refused a vs_ai hint the client thought was open (a rare client
+        // clock desync): re-sync the countdown from a fresh fetch and explain the gate.
+        await load();
+        const left = hintGateRemainingMs(hintGateStart, gateLeftMs, performance.now());
+        showToast(t('game.hintLockedIn', { n: hintLockMinutes(left || 60_000) }), 'info');
       } else {
         handleError(e);
       }
@@ -906,7 +1084,8 @@
     exchangeOpen = false;
     busy = true;
     try {
-      applyMoveResult(await gateway.exchange(id, tiles, variant));
+      applyMoveResult(await source.exchange(id, tiles, variant));
+      if (view?.game.hotseat) await advanceHotseat();
     } catch (e) {
       handleError(e);
     } finally {
@@ -928,7 +1107,15 @@
     if (!view) return '';
     const me = view.game.seats[view.seat];
     if (me?.isWinner) return t('game.won');
-    return view.game.seats.some((s) => s.isWinner) ? t('game.lost') : t('game.tied');
+    if (view.game.endReason === 'aborted') return t('game.tied'); // an abort is a draw for everyone
+    const myScore = me?.score ?? 0;
+    // A declared winner (incl. by resignation) that is not me, or anyone who scored higher → a loss.
+    if (view.game.seats.some((s) => s.isWinner) || view.game.seats.some((s) => !s.resigned && s.score > myScore)) {
+      return t('game.lost');
+    }
+    // No one above me and no declared winner: a tie for the lead is a (shared) win; only an
+    // all-level finish is a draw.
+    return view.game.seats.filter((s) => !s.resigned).every((s) => s.score === myScore) ? t('game.tied') : t('game.won');
   }
 
   // The finished-game export offers two formats — the GCG file and the server-rendered PNG
@@ -1244,8 +1431,9 @@
   // (not the still-empty seat of an open game) who is not yet a friend (an already-requested
   // opponent still shows it, but disabled).
   function canAddFriend(s: { accountId: string; seat: number }): boolean {
-    // Never offer add-friend against an AI opponent, an existing friend, or a blocked player.
+    // Never offer add-friend against an AI opponent, an existing friend, or a blocked player — nor in
-    if (view?.game.vsAi) return false;
+    // a local (offline) game, whose seats are account-less: vs_ai, and hotseat's synthetic seat ids.
+    if (view?.game.vsAi || isLocalGameId(id)) return false;
     return (
       !!s.accountId &&
       !app.profile?.isGuest &&
@@ -1259,7 +1447,7 @@
   // may still be blocked (the block overrides the friendship), so it omits the friend exclusion.
   // An already-blocked opponent hides it (both controls go, and the name is struck).
   function canBlock(s: { accountId: string; seat: number }): boolean {
-    if (view?.game.vsAi) return false;
+    if (view?.game.vsAi || isLocalGameId(id)) return false;
     return !!s.accountId && !app.profile?.isGuest && s.accountId !== app.session?.userId && !seatBlocked(s);
   }
 </script>
@@ -1317,7 +1505,7 @@
       {#if badge}<span class="unread-dot sbadge-dot" class:nudge={badge === 'nudge'}></span>{/if}
       {#each view.game.seats as s (s.seat)}
         <div class="seat" class:turn={view.game.toMove === s.seat && !gameOver} class:win={s.isWinner}>
-          <div class="nm" class:struck={seatBlocked(s)}>{seatName(s)}</div>
+          <div class="nm" class:struck={seatBlocked(s)}>{#if gameOver && view.game.hotseat}<span class="medal" aria-hidden="true">{seatMedal(view.game, s.seat)}</span>{/if}{seatName(s)}</div>
           <div class="sc" class:blockprompt={blockConfirm[s.seat]}>
             {#if blockConfirm[s.seat]}{t('game.blockShort')}{:else if addConfirm[s.seat]}{t('game.addFriendShort')}{:else}{s.score}{/if}
           </div>
@@ -1361,13 +1549,18 @@
         {:else}
           <button class="hicon" onclick={onExportClick} aria-label={t('game.exportGcg')}>📤</button>
         {/if}
+      {:else if view.game.hotseat}
+        <!-- Hotseat resign is a host (referee) action, not self-serve; keep the slot empty. -->
+        <span aria-hidden="true"></span>
       {:else}
         <button class="hicon" onclick={onResignClick} disabled={waitingForOpponent} aria-label={t('game.dropGame')}>🏁</button>
       {/if}
       {#if !view.game.multipleWordsPerTurn}<span class="oneword-label">{t('game.oneWordRule')}</span>{/if}
-      <!-- A finished AI game has no comms at all (no chat, and the dictionary closes with the
+      <!-- The comms entry opens Chat + the word Dictionary. A local game (vs_ai or hotseat) has no
-           game), so the entry is dropped; an active AI game keeps it (it opens the dictionary). -->
+           chat, so its hub is Dictionary-only (CommsHub), and once finished the dictionary closes too
-      {#if !(gameOver && view.game.vsAi)}
+           — so drop the entry only when a local game is finished; an active local game keeps it for
+           the Dictionary. An online game always keeps it (chat outlives the game). -->
+      {#if !(gameOver && (view.game.vsAi || view.game.hotseat))}
         <button class="hicon" onclick={() => navigate(`/game/${id}/chat`)} aria-label={t('game.chat')}>
           {#key chatBlink}<span class="chat-ico" class:blink={chatBlink > 0 && !app.reduceMotion}>💬</span>{/key}
         </button>
@@ -1438,9 +1631,12 @@
     <div class="status">
       <span>{view.bagLen === 0 ? t('game.bagEmpty') : t('game.bag', { n: view.bagLen })}</span>
       {#if gameOver}
-        <strong class="over">{resultText()}</strong>
+        <!-- A hotseat game shows its result as per-seat medals on the plaques (below), not a
+             viewer-centric "you won/lost" — with 2-4 local players there is no single "you". A vs_ai
+             game keeps the "you won/lost" text (one human). -->
+        {#if !view.game.hotseat}<strong class="over">{resultText()}</strong>{/if}
       {:else if placement.pending.length === 0}
-        <span class="turn-ind">{isMyTurn ? t('game.yourTurn') : turnLabel()}</span>
+        <span class="turn-ind">{view.game.hotseat ? t('hotseat.turnOf', { name: hotseatName(view.game.toMove) }) : isMyTurn ? t('game.yourTurn') : turnLabel()}</span>
       {/if}
       <span class="scores">
         {#if recallOverRack}{:else if preview}{preview.legal ? t('game.previewWords', { words: preview.words.join(', '), n: preview.score }) : t('game.previewIllegal')}{/if}
@@ -1454,36 +1650,58 @@
        a finished game shows the final rack greyed out and the controls disabled. -->
   <div class="rack-row" class:inert={gameOver} data-coach="game-rack">
     <div class="rack-wrap">
-      <Rack
+      {#if locked}
-        slots={rackSlots}
+        <!-- A PIN-locked hotseat seat: the rack is withheld until its owner unlocks it. The board
-        {variant}
+             above stays visible; only this tray is gated. -->
-        {selected}
+        <button class="unlock" onclick={() => (unlockOpen = true)}>🔒 {t('hotseat.unlock')}</button>
-        {landscape}
+      {:else}
-        shuffling={shuffling && !app.reduceMotion}
+        <Rack
-        draggingId={reorderDragId}
+          slots={rackSlots}
-        dropIndex={reorderTo}
+          {variant}
-        ondown={onRackDown}
+          {selected}
-      />
+          {landscape}
+          shuffling={shuffling && !app.reduceMotion}
+          draggingId={reorderDragId}
+          dropIndex={reorderTo}
+          ondown={onRackDown}
+        />
+      {/if}
     </div>
     {#if !gameOver && placement.pending.length > 0 && !recallOverRack}
-      <button class="make" onclick={commit} disabled={busy || !isMyTurn || !connection.online || !preview?.legal} aria-label={t('game.makeMove')}>✅</button>
+      <button class="make" onclick={commit} disabled={busy || !canMove || !netReady || !preview?.legal} aria-label={t('game.makeMove')}>✅</button>
     {/if}
   </div>
 {/snippet}
 
 {#snippet controlButtons()}
-  <button class="tab" disabled={busy || !isMyTurn || !connection.online} onclick={openExchange}>
+  <button class="tab" disabled={busy || !canMove || !netReady} onclick={openExchange}>
     <span class="sq" data-coach="game-turn">🔄</span><span class="lbl">{t('game.draw')}</span>
   </button>
-  <TapConfirm
+  {#if view?.game.hotseat}
-    triggerClass="tab"
+    <!-- Hotseat: no hints. The freed slot becomes the host (referee) button — always available
-    label={t('game.hint')}
+         (even on a locked seat: the host may skip a player who forgot their PIN). -->
-    disabled={busy || !isMyTurn || !connection.online || hintCount <= 0}
+    <button class="tab" disabled={busy || gameOver} onclick={() => (hostMenuStep = 'pin')}>
-    onconfirm={doHint}
+      <span class="sq">🔐</span><span class="lbl">{t('hotseat.host')}</span>
-  >
+    </button>
-    <span class="sq" data-coach="game-hints">🛟{#if hintCount > 0}<span class="badge">{hintCount}</span>{/if}</span>
+  {:else if view?.game.vsAi}
-    <span class="lbl">{t('game.hint')}</span>
+    <!-- vs_ai hints are unlimited and wallet-free, so no confirm and no count. A 🔒 badge marks the
-  </TapConfirm>
+         idle gate while it is closed; tapping then only explains when it opens (doHint), and the lock
+         lifts live at the unlock moment. -->
+    <button class="tab" disabled={busy || !isMyTurn || !netReady} onclick={doHint}>
+      <span class="sq" data-coach="game-hints">🛟{#if hintGated}<span class="lock" aria-hidden="true">🔒</span>{/if}</span>
+      <span class="lbl">{t('game.hint')}</span>
+    </button>
+  {:else}
+    <TapConfirm
+      triggerClass="tab"
+      label={t('game.hint')}
+      disabled={busy || !isMyTurn || !netReady || hintCount <= 0}
+      onconfirm={doHint}
+    >
+      <span class="sq" data-coach="game-hints">🛟{#if hintCount > 0}<span class="badge">{hintCount}</span>{/if}</span>
+      <span class="lbl">{t('game.hint')}</span>
+    </TapConfirm>
+  {/if}
   {#if placement.pending.length > 0}
     <button class="tab" disabled={busy} onclick={resetPlacement}>
       <span class="sq">↩️</span><span class="lbl">{t('game.reset')}</span>
@@ -1536,11 +1754,60 @@
   <Modal title={t('game.confirmResign')} onclose={() => (resignOpen = false)}>
     <div class="confirm-row">
       <button class="cancel" onclick={() => (resignOpen = false)}>{t('common.cancel')}</button>
-      <button class="danger" onclick={doResign} disabled={!connection.online}>{t('game.dropGame')}</button>
+      <button class="danger" onclick={doResign} disabled={!netReady}>{t('game.dropGame')}</button>
     </div>
   </Modal>
 {/if}
 
+<!-- Offline hotseat: unlock the current seat's rack. -->
+{#if unlockOpen && view}
+  <PinPad
+    mode="verify"
+    title={t('hotseat.unlockTitle', { name: hotseatName(view.game.toMove) })}
+    verify={onUnlock}
+    onclose={() => (unlockOpen = false)}
+    onresult={() => (unlockOpen = false)}
+  />
+{/if}
+
+<!-- Offline hotseat: the host (referee) enters the master PIN, then picks an override. -->
+{#if hostMenuStep === 'pin'}
+  <PinPad
+    mode="verify"
+    title={t('hotseat.host')}
+    verify={verifyHost}
+    onclose={() => (hostMenuStep = 'closed')}
+    onresult={() => (hostMenuStep = 'menu')}
+  />
+{/if}
+{#if hostMenuStep === 'menu' && view}
+  <Modal title={t('hotseat.host')} onclose={() => { hostMenuStep = 'closed'; hostConfirm = null; }}>
+    {#if hostConfirm}
+      <p class="host-q">{hostConfirmText(hostConfirm)}</p>
+      <div class="confirm-row">
+        <button class="cancel" onclick={() => (hostConfirm = null)}>{t('common.cancel')}</button>
+        <button class="danger" onclick={runHostAction}>{t('common.ok')}</button>
+      </div>
+    {:else}
+      <div class="host-menu">
+        <button class="host-act" onclick={startSkip}>
+          {t('hotseat.skip')}
+        </button>
+        <div class="host-sub">{t('hotseat.exclude')}</div>
+        {#each view.game.seats as s (s.seat)}
+          <button class="host-seat" onclick={() => (hostConfirm = { action: 'resign', seat: s.seat, name: s.displayName })}>
+            {s.displayName}
+          </button>
+        {/each}
+        <button class="host-act danger" onclick={() => (hostConfirm = { action: 'terminate' })}>{t('hotseat.terminate')}</button>
+      </div>
+    {/if}
+  </Modal>
+{/if}
+{#if hostDone}
+  <div class="host-done" aria-hidden="true">✅</div>
+{/if}
+
 {#if exportOpen}
   <Modal title={t('game.exportGcg')} onclose={() => (exportOpen = false)}>
     <div class="export-opts">
@@ -1548,7 +1815,7 @@
         <button
           class="confirm"
           onclick={() => { exportOpen = false; void exportArtifact('png'); }}
-          disabled={!connection.online}
+          disabled={!netReady}
         >
           {t('game.exportImageOpt')}
         </button>
@@ -1556,7 +1823,7 @@
       <button
         class={exportImageAvailable ? 'export-alt' : 'confirm'}
         onclick={() => { exportOpen = false; void exportArtifact('gcg'); }}
-        disabled={!connection.online}
+        disabled={!netReady}
       >
         {t('game.exportGcgOpt')}
       </button>
@@ -1610,6 +1877,10 @@
     overflow: hidden;
     text-overflow: ellipsis;
   }
+  /* The finished-game place medal on a local (offline) seat plaque, left of the name. */
+  .medal {
+    margin-right: 3px;
+  }
   .sc {
     font-weight: 700;
     font-variant-numeric: tabular-nums;
@@ -2031,4 +2302,76 @@
   .scoreboard.flat {
     cursor: default;
   }
+  /* The vs_ai hint's idle lock: a small 🔒 at the icon-square corner (the .sq is positioned by the
+     shared TabBar rule). No count pill — the hint is unlimited; the lock alone marks the gate. */
+  .sq .lock {
+    position: absolute;
+    top: -4px;
+    right: -4px;
+    font-size: 0.62rem;
+    line-height: 1;
+  }
+  /* --- offline hotseat --- */
+  /* The locked-seat rack overlay: fills the rack tray with an "unlock" button, the board above
+     stays visible. */
+  .unlock {
+    width: 100%;
+    height: 100%;
+    min-height: 44px;
+    border: 1px dashed var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-weight: 600;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 8px;
+  }
+  .host-menu {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+  }
+  .host-act,
+  .host-seat {
+    padding: 12px;
+    border: 1px solid var(--border);
+    border-radius: var(--radius-sm);
+    background: var(--surface);
+    color: var(--text);
+    font-weight: 600;
+    text-align: left;
+  }
+  .host-act.danger {
+    border-color: var(--danger);
+    color: var(--danger);
+  }
+  .host-sub {
+    font-size: 0.8rem;
+    color: var(--text-muted);
+    margin-top: 4px;
+  }
+  .host-q {
+    margin: 0 0 12px;
+    font-weight: 600;
+  }
+  /* The transient success tick after a host override — a centred ✅ that fades out on a timer. */
+  .host-done {
+    position: fixed;
+    inset: 0;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    font-size: 4rem;
+    z-index: 50;
+    pointer-events: none;
+    animation: host-done-fade 1.1s ease forwards;
+  }
+  @keyframes host-done-fade {
+    0% { opacity: 0; transform: scale(0.7); }
+    25% { opacity: 1; transform: scale(1); }
+    75% { opacity: 1; transform: scale(1); }
+    100% { opacity: 0; transform: scale(1); }
+  }
 </style>

ui/src/gen/fbs/scrabblefb.ts

@@ -17,6 +17,7 @@ export { ChatPostRequest } from './scrabblefb/chat-post-request.js';
 export { CheckWordRequest } from './scrabblefb/check-word-request.js';
 export { ComplaintRequest } from './scrabblefb/complaint-request.js';
 export { CreateInvitationRequest } from './scrabblefb/create-invitation-request.js';
+export { DictVersion } from './scrabblefb/dict-version.js';
 export { DraftRequest } from './scrabblefb/draft-request.js';
 export { DraftView } from './scrabblefb/draft-view.js';
 export { EmailConfirmLinkRequest } from './scrabblefb/email-confirm-link-request.js';

ui/src/gen/fbs/scrabblefb/banner-campaign.ts

@@ -37,8 +37,50 @@ messagesLength():number {
   return offset ? this.bb!.__vector_len(this.bb_pos + offset) : 0;
 }
 
+overrideBg():string|null
+overrideBg(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideBg(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 8);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+overrideFg():string|null
+overrideFg(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideFg(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 10);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+overrideLink():string|null
+overrideLink(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideLink(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 12);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+overrideBgDark():string|null
+overrideBgDark(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideBgDark(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 14);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+overrideFgDark():string|null
+overrideFgDark(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideFgDark(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 16);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+overrideLinkDark():string|null
+overrideLinkDark(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+overrideLinkDark(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 18);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
 static startBannerCampaign(builder:flatbuffers.Builder) {
-  builder.startObject(2);
+  builder.startObject(8);
 }
 
 static addWeight(builder:flatbuffers.Builder, weight:number) {
@@ -61,15 +103,45 @@ static startMessagesVector(builder:flatbuffers.Builder, numElems:number) {
   builder.startVector(4, numElems, 4);
 }
 
+static addOverrideBg(builder:flatbuffers.Builder, overrideBgOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(2, overrideBgOffset, 0);
+}
+
+static addOverrideFg(builder:flatbuffers.Builder, overrideFgOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(3, overrideFgOffset, 0);
+}
+
+static addOverrideLink(builder:flatbuffers.Builder, overrideLinkOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(4, overrideLinkOffset, 0);
+}
+
+static addOverrideBgDark(builder:flatbuffers.Builder, overrideBgDarkOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(5, overrideBgDarkOffset, 0);
+}
+
+static addOverrideFgDark(builder:flatbuffers.Builder, overrideFgDarkOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(6, overrideFgDarkOffset, 0);
+}
+
+static addOverrideLinkDark(builder:flatbuffers.Builder, overrideLinkDarkOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(7, overrideLinkDarkOffset, 0);
+}
+
 static endBannerCampaign(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;
 }
 
-static createBannerCampaign(builder:flatbuffers.Builder, weight:number, messagesOffset:flatbuffers.Offset):flatbuffers.Offset {
+static createBannerCampaign(builder:flatbuffers.Builder, weight:number, messagesOffset:flatbuffers.Offset, overrideBgOffset:flatbuffers.Offset, overrideFgOffset:flatbuffers.Offset, overrideLinkOffset:flatbuffers.Offset, overrideBgDarkOffset:flatbuffers.Offset, overrideFgDarkOffset:flatbuffers.Offset, overrideLinkDarkOffset:flatbuffers.Offset):flatbuffers.Offset {
   BannerCampaign.startBannerCampaign(builder);
   BannerCampaign.addWeight(builder, weight);
   BannerCampaign.addMessages(builder, messagesOffset);
+  BannerCampaign.addOverrideBg(builder, overrideBgOffset);
+  BannerCampaign.addOverrideFg(builder, overrideFgOffset);
+  BannerCampaign.addOverrideLink(builder, overrideLinkOffset);
+  BannerCampaign.addOverrideBgDark(builder, overrideBgDarkOffset);
+  BannerCampaign.addOverrideFgDark(builder, overrideFgDarkOffset);
+  BannerCampaign.addOverrideLinkDark(builder, overrideLinkDarkOffset);
   return BannerCampaign.endBannerCampaign(builder);
 }
 }

ui/src/gen/fbs/scrabblefb/dict-version.ts

@@ -0,0 +1,60 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class DictVersion {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):DictVersion {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsDictVersion(bb:flatbuffers.ByteBuffer, obj?:DictVersion):DictVersion {
+  return (obj || new DictVersion()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsDictVersion(bb:flatbuffers.ByteBuffer, obj?:DictVersion):DictVersion {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new DictVersion()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+variant():string|null
+variant(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+variant(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+version():string|null
+version(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+version(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 6);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startDictVersion(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addVariant(builder:flatbuffers.Builder, variantOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, variantOffset, 0);
+}
+
+static addVersion(builder:flatbuffers.Builder, versionOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, versionOffset, 0);
+}
+
+static endDictVersion(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createDictVersion(builder:flatbuffers.Builder, variantOffset:flatbuffers.Offset, versionOffset:flatbuffers.Offset):flatbuffers.Offset {
+  DictVersion.startDictVersion(builder);
+  DictVersion.addVariant(builder, variantOffset);
+  DictVersion.addVersion(builder, versionOffset);
+  return DictVersion.endDictVersion(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/email-request-request.ts

@@ -41,8 +41,13 @@ language(optionalEncoding?:any):string|Uint8Array|null {
   return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
 }
 
+pwa():boolean {
+  const offset = this.bb!.__offset(this.bb_pos, 10);
+  return offset ? !!this.bb!.readInt8(this.bb_pos + offset) : false;
+}
+
 static startEmailRequestRequest(builder:flatbuffers.Builder) {
-  builder.startObject(3);
+  builder.startObject(4);
 }
 
 static addEmail(builder:flatbuffers.Builder, emailOffset:flatbuffers.Offset) {
@@ -57,16 +62,21 @@ static addLanguage(builder:flatbuffers.Builder, languageOffset:flatbuffers.Offse
   builder.addFieldOffset(2, languageOffset, 0);
 }
 
+static addPwa(builder:flatbuffers.Builder, pwa:boolean) {
+  builder.addFieldInt8(3, +pwa, +false);
+}
+
 static endEmailRequestRequest(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;
 }
 
-static createEmailRequestRequest(builder:flatbuffers.Builder, emailOffset:flatbuffers.Offset, browserTzOffset:flatbuffers.Offset, languageOffset:flatbuffers.Offset):flatbuffers.Offset {
+static createEmailRequestRequest(builder:flatbuffers.Builder, emailOffset:flatbuffers.Offset, browserTzOffset:flatbuffers.Offset, languageOffset:flatbuffers.Offset, pwa:boolean):flatbuffers.Offset {
   EmailRequestRequest.startEmailRequestRequest(builder);
   EmailRequestRequest.addEmail(builder, emailOffset);
   EmailRequestRequest.addBrowserTz(builder, browserTzOffset);
   EmailRequestRequest.addLanguage(builder, languageOffset);
+  EmailRequestRequest.addPwa(builder, pwa);
   return EmailRequestRequest.endEmailRequestRequest(builder);
 }
 }

ui/src/gen/fbs/scrabblefb/profile.ts

@@ -3,6 +3,7 @@
 import * as flatbuffers from 'flatbuffers';
 
 import { BannerInfo } from '../scrabblefb/banner-info.js';
+import { DictVersion } from '../scrabblefb/dict-version.js';
 
 
 export class Profile {
@@ -124,8 +125,18 @@ vkLinked():boolean {
   return offset ? !!this.bb!.readInt8(this.bb_pos + offset) : false;
 }
 
+dictVersions(index: number, obj?:DictVersion):DictVersion|null {
+  const offset = this.bb!.__offset(this.bb_pos, 36);
+  return offset ? (obj || new DictVersion()).__init(this.bb!.__indirect(this.bb!.__vector(this.bb_pos + offset) + index * 4), this.bb!) : null;
+}
+
+dictVersionsLength():number {
+  const offset = this.bb!.__offset(this.bb_pos, 36);
+  return offset ? this.bb!.__vector_len(this.bb_pos + offset) : 0;
+}
+
 static startProfile(builder:flatbuffers.Builder) {
-  builder.startObject(16);
+  builder.startObject(17);
 }
 
 static addUserId(builder:flatbuffers.Builder, userIdOffset:flatbuffers.Offset) {
@@ -204,6 +215,22 @@ static addVkLinked(builder:flatbuffers.Builder, vkLinked:boolean) {
   builder.addFieldInt8(15, +vkLinked, +false);
 }
 
+static addDictVersions(builder:flatbuffers.Builder, dictVersionsOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(16, dictVersionsOffset, 0);
+}
+
+static createDictVersionsVector(builder:flatbuffers.Builder, data:flatbuffers.Offset[]):flatbuffers.Offset {
+  builder.startVector(4, data.length, 4);
+  for (let i = data.length - 1; i >= 0; i--) {
+    builder.addOffset(data[i]!);
+  }
+  return builder.endVector();
+}
+
+static startDictVersionsVector(builder:flatbuffers.Builder, numElems:number) {
+  builder.startVector(4, numElems, 4);
+}
+
 static endProfile(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;

ui/src/gen/fbs/scrabblefb/state-view.ts

@@ -74,8 +74,13 @@ walletBalance():number {
   return offset ? this.bb!.readInt32(this.bb_pos + offset) : 0;
 }
 
+hintUnlockLeftSeconds():number {
+  const offset = this.bb!.__offset(this.bb_pos, 18);
+  return offset ? this.bb!.readInt32(this.bb_pos + offset) : 0;
+}
+
 static startStateView(builder:flatbuffers.Builder) {
-  builder.startObject(7);
+  builder.startObject(8);
 }
 
 static addGame(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset) {
@@ -130,12 +135,16 @@ static addWalletBalance(builder:flatbuffers.Builder, walletBalance:number) {
   builder.addFieldInt32(6, walletBalance, 0);
 }
 
+static addHintUnlockLeftSeconds(builder:flatbuffers.Builder, hintUnlockLeftSeconds:number) {
+  builder.addFieldInt32(7, hintUnlockLeftSeconds, 0);
+}
+
 static endStateView(builder:flatbuffers.Builder):flatbuffers.Offset {
   const offset = builder.endObject();
   return offset;
 }
 
-static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset, seat:number, rackOffset:flatbuffers.Offset, bagLen:number, hintsRemaining:number, alphabetOffset:flatbuffers.Offset, walletBalance:number):flatbuffers.Offset {
+static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offset, seat:number, rackOffset:flatbuffers.Offset, bagLen:number, hintsRemaining:number, alphabetOffset:flatbuffers.Offset, walletBalance:number, hintUnlockLeftSeconds:number):flatbuffers.Offset {
   StateView.startStateView(builder);
   StateView.addGame(builder, gameOffset);
   StateView.addSeat(builder, seat);
@@ -144,6 +153,7 @@ static createStateView(builder:flatbuffers.Builder, gameOffset:flatbuffers.Offse
   StateView.addHintsRemaining(builder, hintsRemaining);
   StateView.addAlphabet(builder, alphabetOffset);
   StateView.addWalletBalance(builder, walletBalance);
+  StateView.addHintUnlockLeftSeconds(builder, hintUnlockLeftSeconds);
   return StateView.endStateView(builder);
 }
 }

ui/src/lib/app.svelte.ts

@@ -35,12 +35,17 @@ import {
 } from './telegram';
 import { onVKPath, insideVK, vkInit, vkClose, vkDisableSwipeBack, vkLaunchParams, vkUserName, vkStartParam, vkOnScheme, vkOnInsets, vkSetViewSettings, appearanceForBg } from './vk';
 import { pendingVKLink, type VKLinkCallback } from './vkid';
+import { isStandalone } from './pwa';
+import { registerServiceWorker } from './pwa.svelte';
 import { haptic } from './haptics';
 import { CLOUD_PREFS_KEY, decodeClientPrefs, encodeClientPrefs } from './cloudprefs';
 import { parseStartParam } from './deeplink';
 import {
   clearOnboarding,
   clearSession,
+  clearProfile,
+  loadProfile,
+  saveProfile,
   loadOnboarding,
   loadPrefs,
   loadSession,
@@ -50,7 +55,9 @@ import {
   savePrefs,
 } from './session';
 import type { CoachSeries } from './coachmark';
-import { connection, reportOffline, reportOnline, resetConnection } from './connection.svelte';
+import { connection, reportOffline, reportOnline, resetConnection, checkReachable } from './connection.svelte';
+import { offlineMode, setOfflineMode } from './offline.svelte';
+import { shouldBootOffline } from './offline';
 import { isConnectionCode } from './retry';
 import { clearGameCache, getCachedGame, setCachedGame } from './gamecache';
 import { advanceCached } from './gamedelta';
@@ -71,6 +78,10 @@ export const app = $state<{
    *  backend was down during a deploy). App.svelte then renders the boot-error retry screen
    *  instead of the web login — a Mini App has no manual sign-in to fall back to. */
   bootError: boolean;
+  /** True while the cold-start "no connection — go offline?" dialog is up (the reachability check
+   *  timed out with the network interface reportedly online). App.svelte renders it over the splash;
+   *  bootstrap awaits the choice via resolveOfflinePrompt. */
+  offlinePrompt: boolean;
   /** On the dedicated /telegram/ entry, set to a privacy-safe diagnostic snapshot when a Mini App
    *  launch carried no sign-in data (empty initData). App.svelte then renders the compact
    *  launch-error screen (screens/TelegramLaunchError) — a shareable probe for why Telegram
@@ -141,6 +152,7 @@ export const app = $state<{
 }>({
   ready: false,
   bootError: false,
+  offlinePrompt: false,
   launchError: null,
   debugOpen: false,
   lobbyReady: false,
@@ -214,9 +226,9 @@ function goForeground(): void {
 export function showToast(text: string, kind: Toast['kind'] = 'info'): void {
   app.toast = { kind, text, seq: ++toastSeq };
   if (toastTimer) clearTimeout(toastTimer);
-  // An info bubble lives exactly as long as its rise-and-fade animation (2s); an error
+  // An info bubble lives exactly as long as its appear + ~1s hold + rise-and-fade animation (3s);
-  // dwells longer (4s) so it is not missed.
+  // an error dwells longer (4s) so it is not missed.
-  toastTimer = setTimeout(() => (app.toast = null), kind === 'error' ? 4000 : 2000);
+  toastTimer = setTimeout(() => (app.toast = null), kind === 'error' ? 4000 : 3000);
 }
 
 /** dismissToast hides the current toast at once — a tap on the bubble dismisses it. */
@@ -292,7 +304,9 @@ export function handleError(err: unknown): void {
     void enterBlocked();
     return;
   }
-  if (isConnectionCode(code) || !connection.online) return;
+  // A blocked call in offline mode ('offline', the transport kill switch) is expected, not an error
+  // to surface — the offline chrome already signals the state; never a red toast.
+  if (isConnectionCode(code) || code === 'offline' || !connection.online) return;
   haptic('error');
   showToast(t(code ? errorKey(code) : 'error.generic'), 'error');
 }
@@ -458,6 +472,7 @@ export async function refreshProfile(): Promise<void> {
   if (!app.session) return;
   try {
     app.profile = await gateway.profileGet();
+    void saveProfile($state.snapshot(app.profile)); // keep the offline-boot cache fresh (plain snapshot)
   } catch {
     // Best-effort; the banner just stays as it was until the next fetch.
   }
@@ -515,6 +530,11 @@ async function adoptSession(s: Session): Promise<void> {
   await saveSession(s);
   try {
     app.profile = await gateway.profileGet();
+    // Persist the profile so a later offline cold start can launch from it (its variant
+    // preferences, dictionary versions and display name) without a network fetch. Snapshot to a
+    // plain object first — the reactive $state proxy is not structured-cloneable, so it would fail
+    // the IndexedDB write and fall back to a localStorage entry that loadProfile never reads.
+    void saveProfile($state.snapshot(app.profile));
     // The live interface language follows the device — the explicit local choice (saved in
     // prefs) or the system guess made at bootstrap — and is no longer overridden from the
     // account here: the Telegram bot a user signs in through must not dictate the UI, so a
@@ -538,6 +558,74 @@ async function adoptSession(s: Session): Promise<void> {
   void refreshNotifications();
 }
 
+// The cold-start "no connection — go offline?" dialog. bootstrap raises it and awaits the choice
+// here; App.svelte's dialog buttons call resolveOfflinePrompt.
+const BOOT_REACHABILITY_TIMEOUT_MS = 3000;
+let offlinePromptResolve: ((goOffline: boolean) => void) | null = null;
+
+/** resolveOfflinePrompt answers the cold-start "no connection — go offline?" dialog (App.svelte). */
+export function resolveOfflinePrompt(goOffline: boolean): void {
+  app.offlinePrompt = false;
+  const resolve = offlinePromptResolve;
+  offlinePromptResolve = null;
+  resolve?.(goOffline);
+}
+
+/** promptOfflineChoice raises the dialog and resolves to the player's choice (true = go offline). */
+function promptOfflineChoice(): Promise<boolean> {
+  app.offlinePrompt = true;
+  return new Promise<boolean>((resolve) => {
+    offlinePromptResolve = resolve;
+  });
+}
+
+/**
+ * initNetworkReactivity reacts to mid-session network changes (e.g. the player toggling flight mode):
+ * losing the network interface enters offline mode automatically (session-only); regaining it
+ * verifies the gateway is really reachable (an interface being up does not guarantee it) and returns
+ * to online — but only if the offline was auto. A deliberate offline (the Settings toggle or the
+ * cold-start dialog) is left as the player's choice. These are passive OS events — no polling, no
+ * battery cost. Web-only and skipped in the mock (the e2e drives connectivity directly).
+ */
+// While in auto-offline, poll for the network to return so the app comes back online — robust to the
+// unreliable `online` event (which often does not fire in an installed PWA). Each tick is cheap: it
+// reads navigator.onLine (no radio) and only hits the network (a reachability check) when the
+// interface is actually up, so while flight mode is on it costs nothing. The poll runs ONLY in
+// auto-offline (a deliberate offline is the player's choice) and stops on returning online.
+let recoveryTimer: ReturnType<typeof setTimeout> | null = null;
+export function scheduleRecovery(delayMs: number): void {
+  if (recoveryTimer) {
+    clearTimeout(recoveryTimer);
+    recoveryTimer = null;
+  }
+  if (typeof window === 'undefined' || !offlineMode.active || !offlineMode.auto) return;
+  recoveryTimer = setTimeout(async () => {
+    recoveryTimer = null;
+    if (!offlineMode.active || !offlineMode.auto) return;
+    const interfaceUp = typeof navigator === 'undefined' || navigator.onLine;
+    if (interfaceUp && (await checkReachable(BOOT_REACHABILITY_TIMEOUT_MS))) {
+      if (offlineMode.active && offlineMode.auto) setOfflineMode(false);
+      return;
+    }
+    scheduleRecovery(4000);
+  }, delayMs);
+}
+
+export function initNetworkReactivity(): void {
+  if (typeof window === 'undefined' || import.meta.env.MODE === 'mock') return;
+  window.addEventListener('offline', () => {
+    if (!offlineMode.active) {
+      setOfflineMode(true, false); // auto (session)
+      scheduleRecovery(4000); // poll for the network to return
+    }
+  });
+  // The online event, when it fires, just kicks an immediate reachability check; the poll above is
+  // the reliable fallback for platforms where it does not fire.
+  window.addEventListener('online', () => {
+    if (offlineMode.active && offlineMode.auto) scheduleRecovery(0);
+  });
+}
+
 /**
  * applyLinkResult applies a completed account link or merge: it adopts a
  * switched session (a guest initiator whose durable counterpart won, so the active
@@ -637,17 +725,37 @@ function syncTelegramSafeArea(): void {
   root.classList.toggle('tg-fullscreen', top > 0);
 }
 
+// The soft-keyboard height threshold (px) that distinguishes an open keyboard from browser chrome
+// (an address bar shrinks the visual viewport by far less), used to gate the focus-into-view scroll.
+const KEYBOARD_MIN_PX = 120;
+
 /**
- * syncViewportHeight mirrors the visual-viewport height into the --vvh CSS var so a screen can
+ * syncViewport mirrors the visual viewport into CSS vars so the pinned app-shell (app.css
- * fit the visible area above an open soft keyboard (iOS does not shrink dvh for the keyboard).
+ * `html.app-shell body`) both FITS (`--vvh`) and FOLLOWS (`--vv-top`) the visible area above the soft
- * On a screen whose input sits at the bottom (chat, word-check) this keeps the input visible
+ * keyboard. iOS Safari / WKWebView does not shrink the layout viewport for the keyboard (Android
- * without the page scrolling, so the layout no longer jumps when the keyboard appears.
+ * Chrome does); instead the visual viewport shrinks AND offsets down to reveal the focused field, and
+ * those values do not always cleanly revert. Tracking only the height left the top-anchored shell
+ * misaligned on iOS — empty space below the content, worst on a repeat focus; tracking offsetTop too
+ * keeps the shell on the visible area on every platform. On the keyboard-OPEN transition it also
+ * scrolls the focused field into view, since iOS does not reliably scroll a pinned document to it.
  */
-function syncViewportHeight(): void {
+let keyboardOpen = false;
+function syncViewport(): void {
   if (typeof document === 'undefined') return;
-  const vv = typeof window !== 'undefined' ? window.visualViewport : null;
+  const win = typeof window !== 'undefined' ? window : null;
-  const h = vv ? vv.height : typeof window !== 'undefined' ? window.innerHeight : 0;
+  const vv = win ? win.visualViewport : null;
+  const h = vv ? vv.height : win ? win.innerHeight : 0;
+  const top = vv ? vv.offsetTop : 0;
   if (h > 0) document.documentElement.style.setProperty('--vvh', `${h}px`);
+  document.documentElement.style.setProperty('--vv-top', `${top}px`);
+  const open = !!vv && !!win && win.innerHeight - h > KEYBOARD_MIN_PX;
+  if (open && !keyboardOpen) {
+    const el = document.activeElement;
+    if (el instanceof HTMLElement && (el.tagName === 'INPUT' || el.tagName === 'TEXTAREA')) {
+      requestAnimationFrame(() => el.scrollIntoView({ block: 'center' }));
+    }
+  }
+  keyboardOpen = open;
 }
 
 /**
@@ -707,11 +815,23 @@ export async function bootstrap(): Promise<void> {
     setLocale(guess);
   }
 
-  // Track the visual-viewport height so screens fit above an open soft keyboard (--vvh).
+  // Track the visual viewport (height + offset) so screens fit and follow the visible area above an
-  syncViewportHeight();
+  // open soft keyboard (--vvh / --vv-top). Both resize AND scroll fire on iOS when the keyboard moves
+  // the visual viewport.
+  syncViewport();
   if (typeof window !== 'undefined' && window.visualViewport) {
-    window.visualViewport.addEventListener('resize', syncViewportHeight);
+    window.visualViewport.addEventListener('resize', syncViewport);
-    window.visualViewport.addEventListener('scroll', syncViewportHeight);
+    window.visualViewport.addEventListener('scroll', syncViewport);
+  }
+
+  // Enter on a single-line <input> dismisses the soft keyboard (blur): the keyboard's default
+  // return/"Go" key otherwise does nothing on a bare input, which reads as stuck. A <textarea> (the
+  // feedback form) is excluded so Enter still inserts a newline; a form's own Enter→submit still
+  // fires first (this listener is on the document, so it runs after the field's own handler).
+  if (typeof document !== 'undefined') {
+    document.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter' && e.target instanceof HTMLInputElement) e.target.blur();
+    });
   }
 
   // Load the Telegram Mini App SDK dynamically, with a timeout, on a Telegram entry — it is no
@@ -783,11 +903,65 @@ export async function bootstrap(): Promise<void> {
     return;
   }
 
+  // On the plain web (both Mini-App branches returned above) register the install-only service
+  // worker so the app is installable — Chromium needs a registered SW, notably on Android. Web-only
+  // and skipped in the mock build; see lib/pwa.svelte.
+  registerServiceWorker();
+  // React to mid-session network changes (e.g. flight mode) for the rest of the session.
+  initNetworkReactivity();
+
+  // Deliberate offline mode carried over from a prior session: with no network the session adoption
+  // + profile fetch below would hang the splash, so skip them and launch straight from the cached
+  // session + profile into the offline lobby. Without a cached profile (e.g. storage cleared) fall
+  // through to the normal online flow but KEEP the sticky flag — the mode is the player's choice, and
+  // an online boot re-persists the profile so the next launch goes offline. (A truly offline launch
+  // with no cached profile is unreachable: enabling offline requires a prior online session.)
+  if (offlineMode.active) {
+    const [offlineSession, offlineProfile] = await Promise.all([loadSession(), loadProfile()]);
+    if (shouldBootOffline({ offlineActive: true, hasSession: !!offlineSession, hasProfile: !!offlineProfile })) {
+      gateway.setToken(offlineSession!.token);
+      app.session = offlineSession!;
+      app.profile = offlineProfile!;
+      if (router.route.name === 'login' || router.route.name === 'confirm') navigate('/');
+      app.ready = true;
+      return;
+    }
+  }
+
   const saved = await loadSession();
   // A VK ID web-link callback (?code&device_id&state) rides the URL after the redirect back
   // from VK; capture and clear it here (it needs the restored session to link against).
   const vkcb = pendingVKLink();
   if (saved) {
+    // Cold-start network auto-detect (deliberate offline is handled above). With a cached profile to
+    // fall back on and no pending VK-link, do not hang on adoptSession's retrying profile fetch when
+    // the network is down: a device with no network interface goes offline for the session (no
+    // dialog); an interface that is up but cannot reach the gateway within a short window asks the
+    // player. Web-only reaches here (the Mini-App branches returned above), so isStandalone gates it.
+    const cachedProfile = await loadProfile();
+    const canOffline = !!cachedProfile && !vkcb && isStandalone() && !!cachedProfile.email;
+    if (canOffline) {
+      const interfaceOffline = typeof navigator !== 'undefined' && navigator.onLine === false;
+      gateway.setToken(saved.token);
+      const reachable = interfaceOffline ? false : await checkReachable(BOOT_REACHABILITY_TIMEOUT_MS);
+      if (!reachable) {
+        // No network interface → go offline for the session (no dialog); interface up but the
+        // gateway is unreachable → ambiguous, so ask.
+        const goOffline = interfaceOffline ? true : await promptOfflineChoice();
+        if (goOffline) {
+          // A deliberate dialog choice is sticky; an auto (no-interface) offline is session-only.
+          setOfflineMode(true, !interfaceOffline);
+          if (interfaceOffline) scheduleRecovery(4000); // auto-offline: poll for the network to return
+          app.session = saved;
+          app.profile = cachedProfile;
+          if (router.route.name === 'login' || router.route.name === 'confirm') navigate('/');
+          app.ready = true;
+          return;
+        }
+        // "Нет" — keep trying online: fall through to adoptSession (it retries; the connection
+        // watcher shows "Connecting…").
+      }
+    }
     await adoptSession(saved);
     if (vkcb) {
       // The full-page redirect lost the in-app route, so hand the callback to Profile, which
@@ -974,7 +1148,7 @@ export async function loginGuest(): Promise<void> {
 
 export async function requestEmailCode(email: string): Promise<boolean> {
   try {
-    await gateway.authEmailRequest(email, app.locale);
+    await gateway.authEmailRequest(email, app.locale, isStandalone());
     return true;
   } catch (err) {
     handleError(err);
@@ -1016,6 +1190,7 @@ export async function logout(): Promise<void> {
   app.splashDone = false;
   gateway.setToken(null);
   await clearSession();
+  await clearProfile();
   app.session = null;
   app.profile = null;
   navigate('/login');
@@ -1167,4 +1342,11 @@ if (import.meta.env.MODE === 'mock' && typeof window !== 'undefined') {
     closeStream();
     app.blocked = { blocked: true, permanent: true, until: '', reason: '', ...b };
   };
+  // Expose the router so the e2e can assert navigate() updates the route synchronously (no
+  // hashchange lag): a route that trailed the hash for a frame let bootstrap's `app.ready` flip
+  // render the previous route under the new screen (the empty-hash lobby flashing under login).
+  (window as unknown as { __router?: { navigate(p: string): void; route(): string } }).__router = {
+    navigate,
+    route: () => router.route.name,
+  };
 }

ui/src/lib/banner.test.ts

@@ -29,7 +29,7 @@ describe('createScheduler', () => {
       { weight: 7, messages: ['b'] },
     ]);
     expect(sched.total).toBe(2);
-    const cycle = Array.from({ length: 10 }, () => sched.next());
+    const cycle = Array.from({ length: 10 }, () => sched.next().md);
     const a = cycle.filter((m) => m === 'a').length;
     const b = cycle.filter((m) => m === 'b').length;
     expect(a).toBe(3);
@@ -42,7 +42,7 @@ describe('createScheduler', () => {
   it('round-robins messages within a campaign', () => {
     const sched = createScheduler([{ weight: 1, messages: ['m0', 'm1', 'm2'] }]);
     expect(sched.total).toBe(3);
-    expect([sched.next(), sched.next(), sched.next(), sched.next()]).toEqual(['m0', 'm1', 'm2', 'm0']);
+    expect([sched.next().md, sched.next().md, sched.next().md, sched.next().md]).toEqual(['m0', 'm1', 'm2', 'm0']);
   });
 
   it('drops empty and non-positive-weight campaigns', () => {
@@ -52,13 +52,27 @@ describe('createScheduler', () => {
       { weight: 2, messages: ['keep'] },
     ]);
     expect(sched.total).toBe(1);
-    expect(sched.next()).toBe('keep');
+    expect(sched.next().md).toBe('keep');
   });
 
   it('is empty for no campaigns', () => {
     const sched = createScheduler([]);
     expect(sched.total).toBe(0);
-    expect(sched.next()).toBe('');
+    expect(sched.next().md).toBe('');
+  });
+
+  it('carries each campaign colour override with its message', () => {
+    const red = { bg: '#aa0000', fg: '#ffffff', link: '#ffdd00' };
+    const darkRed = { bg: '#330000', fg: '#eeeeee', link: '#ffcc00' };
+    const sched = createScheduler([
+      { weight: 1, messages: ['plain'] },
+      { weight: 1, messages: ['branded'], overrideAll: red, overrideDark: darkRed },
+    ]);
+    const two = [sched.next(), sched.next()];
+    const branded = two.find((it) => it.md === 'branded');
+    const plain = two.find((it) => it.md === 'plain');
+    expect(branded?.colors).toEqual({ all: red, dark: darkRed });
+    expect(plain?.colors).toEqual({ all: null, dark: null });
   });
 });
 

ui/src/lib/banner.ts

@@ -4,7 +4,7 @@
 // unit-testable with fake timers. The campaigns + timings come from the profile's
 // banner block (see lib/model, ARCHITECTURE §10); the host is AdBanner.svelte.
 
-import type { BannerCampaign, BannerTimings } from './model';
+import type { BannerCampaign, BannerColors, BannerTimings } from './model';
 
 /** Fallback display timings, matching the seeded ad_settings defaults. */
 export const defaultBannerTimings: BannerTimings = {
@@ -16,9 +16,15 @@ export const defaultBannerTimings: BannerTimings = {
   fadeInMs: 1_000,
 };
 
+/** BannerItem is one scheduled message plus its campaign's colour override (for the strip). */
+export interface BannerItem {
+  md: string;
+  colors: BannerColors;
+}
+
 /** Scheduler yields the next message to show, fairly across weighted campaigns. */
 export interface Scheduler {
-  next(): string;
+  next(): BannerItem;
   /** Total messages across all (non-empty, positive-weight) campaigns. */
   readonly total: number;
 }
@@ -33,15 +39,17 @@ export interface Scheduler {
  */
 export function createScheduler(campaigns: BannerCampaign[]): Scheduler {
   const cs = campaigns.filter((c) => c.weight > 0 && c.messages.length > 0);
+  const colors: BannerColors[] = cs.map((c) => ({ all: c.overrideAll ?? null, dark: c.overrideDark ?? null }));
   const current = cs.map(() => 0); // SWRR running weights
   const cursor = cs.map(() => 0); // per-campaign round-robin position
   const totalWeight = cs.reduce((sum, c) => sum + c.weight, 0);
   const total = cs.reduce((sum, c) => sum + c.messages.length, 0);
+  const empty: BannerColors = { all: null, dark: null };
 
   return {
     total,
-    next(): string {
+    next(): BannerItem {
-      if (cs.length === 0) return '';
+      if (cs.length === 0) return { md: '', colors: empty };
       let best = 0;
       for (let i = 0; i < cs.length; i++) {
         current[i] += cs[i].weight;
@@ -51,15 +59,16 @@ export function createScheduler(campaigns: BannerCampaign[]): Scheduler {
       const c = cs[best];
       const md = c.messages[cursor[best] % c.messages.length];
       cursor[best]++;
-      return md;
+      return { md, colors: colors[best] };
     },
   };
 }
 
 /** The host the rotator drives; AdBanner.svelte supplies the DOM measurements and effects. */
 export interface BannerHost {
-  /** Render md and fade it in (over fadeInMs), with the scroll reset to the start. */
+  /** Render md and fade it in (over fadeInMs), with the scroll reset to the start. colors is the
-  show(md: string): void;
+   *  source campaign's colour override, applied to the strip (its neutral tokens when unset). */
+  show(md: string, colors: BannerColors): void;
   /** Reset the scroll to the start without re-fading (to loop a long message). */
   resetScroll(): void;
   /** Fade the current message out over durationMs. */
@@ -98,7 +107,7 @@ export function createBannerRotator(
   const sched = createScheduler(campaigns);
   let running = false;
   let cycleStart = 0;
-  let lastShown = ''; // the message currently presented, for restart() (re-measure)
+  let lastShown: BannerItem | null = null; // the item currently presented, for restart() (re-measure)
   const timers: ReturnType<typeof setTimeout>[] = [];
 
   const at = (ms: number, fn: () => void) => {
@@ -109,11 +118,11 @@ export function createBannerRotator(
     timers.length = 0;
   };
 
-  function present(md: string) {
+  function present(item: BannerItem) {
     if (!running) return;
     clear();
-    lastShown = md;
+    lastShown = item;
-    host.show(md);
+    host.show(item.md, item.colors);
     at(config.fadeInMs, measure);
   }
 
@@ -143,7 +152,7 @@ export function createBannerRotator(
           // the same fade as a message change, not a hard jump.
           host.hide(config.fadeOutMs);
           at(config.fadeOutMs + config.gapMs, () => {
-            host.show(lastShown);
+            if (lastShown) host.show(lastShown.md, lastShown.colors);
             at(config.fadeInMs, () => scrollCycle(over));
           });
         }

ui/src/lib/bannerColors.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from 'vitest';
+import { derivedBorder, resolveBannerColors } from './bannerColors';
+import type { BannerColors } from './model';
+
+const red = { bg: '#aa0000', fg: '#ffffff', link: '#ffdd00' };
+const darkRed = { bg: '#330000', fg: '#eeeeee', link: '#ffcc00' };
+
+describe('resolveBannerColors', () => {
+  it('returns null when the campaign has no override (neutral tokens)', () => {
+    const none: BannerColors = { all: null, dark: null };
+    expect(resolveBannerColors(none, 'light')).toBeNull();
+    expect(resolveBannerColors(none, 'dark')).toBeNull();
+  });
+
+  it('applies the all-themes set on both themes when no dark override', () => {
+    const c: BannerColors = { all: red, dark: null };
+    expect(resolveBannerColors(c, 'light')).toMatchObject({ bg: red.bg, fg: red.fg, link: red.link });
+    expect(resolveBannerColors(c, 'dark')).toMatchObject({ bg: red.bg, fg: red.fg, link: red.link });
+  });
+
+  it('prefers the dark override on the dark theme, and the all set on light', () => {
+    const c: BannerColors = { all: red, dark: darkRed };
+    expect(resolveBannerColors(c, 'light')).toMatchObject({ bg: red.bg });
+    expect(resolveBannerColors(c, 'dark')).toMatchObject({ bg: darkRed.bg });
+  });
+
+  it('supports a dark-only override (light keeps the neutral tokens)', () => {
+    const c: BannerColors = { all: null, dark: darkRed };
+    expect(resolveBannerColors(c, 'light')).toBeNull();
+    expect(resolveBannerColors(c, 'dark')).toMatchObject({ bg: darkRed.bg });
+  });
+
+  it('derives the border from the resolved background', () => {
+    const c: BannerColors = { all: red, dark: null };
+    expect(resolveBannerColors(c, 'light')?.border).toBe(derivedBorder(red.bg));
+  });
+});
+
+describe('derivedBorder', () => {
+  it('darkens a light background and lightens a dark one', () => {
+    expect(derivedBorder('#ffffff')).toBe('#dbdbdb');
+    expect(derivedBorder('#000000')).toBe('#242424');
+  });
+
+  it('returns a malformed colour unchanged', () => {
+    expect(derivedBorder('nope')).toBe('nope');
+  });
+});

ui/src/lib/bannerColors.ts

@@ -0,0 +1,69 @@
+// Banner colour resolution. A campaign may carry two optional colour sets (see
+// lib/model BannerColors): one for every theme and one that further overrides the
+// dark theme. resolveBannerColors collapses them to the colours the strip paints on
+// the currently-rendered theme, or null when the campaign keeps the neutral
+// --ad-bg / --text-muted / --accent tokens. Pure and DOM-free, so it is unit-tested
+// directly; AdBanner.svelte applies the result as inline CSS variables.
+
+import type { BannerColors } from './model';
+
+export type ThemeMode = 'light' | 'dark';
+
+/** ResolvedBannerColors is the strip's colours for one theme, border already derived. */
+export interface ResolvedBannerColors {
+  bg: string;
+  fg: string;
+  link: string;
+  border: string;
+}
+
+/**
+ * resolveBannerColors picks the colour set for the rendered theme — dark ← dark ?? all,
+ * light ← all — and returns null when there is no override for that theme (the strip then
+ * keeps the neutral tokens). The border is derived from the background so it stays subtle
+ * on any colour.
+ */
+export function resolveBannerColors(colors: BannerColors, mode: ThemeMode): ResolvedBannerColors | null {
+  const set = mode === 'dark' ? (colors.dark ?? colors.all) : colors.all;
+  if (!set) return null;
+  return { bg: set.bg, fg: set.fg, link: set.link, border: derivedBorder(set.bg) };
+}
+
+/**
+ * derivedBorder nudges the background 14% toward black on a light background and toward
+ * white on a dark one — a subtle edge that suits any override colour. It is computed in
+ * JS (no CSS color-mix) so it works on the old Android WebView floor (Chrome 67), and
+ * mirrors the admin console preview (banner_detail.gohtml). A malformed colour is
+ * returned unchanged.
+ */
+export function derivedBorder(bgHex: string): string {
+  const rgb = hexToRgb(bgHex);
+  if (!rgb) return bgHex;
+  const target: RGB = luminance(rgb) > 0.5 ? [0, 0, 0] : [255, 255, 255];
+  return rgbToHex(mix(rgb, target, 0.14));
+}
+
+type RGB = [number, number, number];
+
+function hexToRgb(h: string): RGB | null {
+  const m = /^#([0-9a-fA-F]{6})$/.exec(h.trim());
+  if (!m) return null;
+  const n = m[1];
+  return [parseInt(n.slice(0, 2), 16), parseInt(n.slice(2, 4), 16), parseInt(n.slice(4, 6), 16)];
+}
+
+function mix(a: RGB, b: RGB, t: number): RGB {
+  return [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t, a[2] + (b[2] - a[2]) * t];
+}
+
+function luminance(r: RGB): number {
+  return (0.2126 * r[0] + 0.7152 * r[1] + 0.0722 * r[2]) / 255;
+}
+
+function pad(x: number): string {
+  return Math.max(0, Math.min(255, Math.round(x))).toString(16).padStart(2, '0');
+}
+
+function rgbToHex(r: RGB): string {
+  return '#' + pad(r[0]) + pad(r[1]) + pad(r[2]);
+}

ui/src/lib/bannerEngine.ts

@@ -4,11 +4,14 @@
 // independent of route transitions (the cycle is not restarted on navigation).
 
 import { createBannerRotator, type BannerHost, type Rotator } from './banner';
-import type { BannerCampaign, BannerTimings } from './model';
+import type { BannerCampaign, BannerColors, BannerTimings } from './model';
+
+const noColors: BannerColors = { all: null, dark: null };
 
 let rotator: Rotator | null = null;
 let mounted: BannerHost | null = null;
 let current = '';
+let currentColors: BannerColors = noColors;
 let key = '';
 // The in-flight horizontal scroll of the current message, so a view mounted by navigation can
 // resume it from the same offset instead of restarting at the left. Null when not scrolling.
@@ -17,10 +20,11 @@ let activeScroll: { toPx: number; dur: number; start: number } | null = null;
 // proxy is the rotator's host: it records the current message + scroll (so a freshly-mounted view
 // can resume them) and forwards every effect to the currently-attached DOM host, if any.
 const proxy: BannerHost = {
-  show(md) {
+  show(md, colors) {
     current = md;
+    currentColors = colors;
     activeScroll = null;
-    mounted?.show(md);
+    mounted?.show(md, colors);
   },
   resetScroll() {
     activeScroll = null;
@@ -58,6 +62,7 @@ export function configureBanner(campaigns: BannerCampaign[], timings: BannerTimi
   key = k;
   rotator?.stop();
   current = '';
+  currentColors = noColors;
   rotator = createBannerRotator(campaigns, proxy, timings);
   rotator.start();
 }
@@ -71,6 +76,15 @@ export function bannerCurrent(): string {
   return current;
 }
 
+/**
+ * bannerCurrentColors returns the colour override of the campaign whose message is currently
+ * displayed (neutral tokens — both sets null — before the first message). A freshly-mounted view
+ * reads it alongside bannerCurrent so the strip paints the right colours immediately on mount.
+ */
+export function bannerCurrentColors(): BannerColors {
+  return currentColors;
+}
+
 /**
  * attachBannerHost connects a freshly-mounted view as the DOM host. It does NOT re-show the
  * current message (the view renders it itself from bannerCurrent on mount): re-showing here would

ui/src/lib/client.ts

@@ -65,7 +65,7 @@ export interface GatewayClient {
    *  cosmetic seed for a brand-new account). */
   authVK(params: string, displayName: string): Promise<Session>;
   authGuest(locale?: string): Promise<Session>;
-  authEmailRequest(email: string, language: string): Promise<void>;
+  authEmailRequest(email: string, language: string, pwa: boolean): Promise<void>;
   authEmailLogin(email: string, code: string): Promise<Session>;
   /** Confirm a one-tap email deeplink token: a login returns a session to adopt; a
    *  link returns a status ('confirmed' | 'merge_required'). */

ui/src/lib/codec.test.ts

@@ -122,10 +122,11 @@ describe('codec', () => {
     expect(guest.browserTz()).toBe('-05:30');
 
     const email = fb.EmailRequestRequest.getRootAsEmailRequestRequest(
-      new ByteBuffer(encodeEmailRequest('a@example.com', '+00:00', 'en')),
+      new ByteBuffer(encodeEmailRequest('a@example.com', '+00:00', 'en', true)),
     );
     expect(email.email()).toBe('a@example.com');
     expect(email.browserTz()).toBe('+00:00');
+    expect(email.pwa()).toBe(true);
     expect(email.language()).toBe('en');
 
     const confirm = fb.EmailConfirmLinkRequest.getRootAsEmailConfirmLinkRequest(
@@ -647,7 +648,10 @@ describe('codec', () => {
     const uid = b.createString('u-1');
     const m0 = b.createString('promo-en');
     const msgs = fb.BannerCampaign.createMessagesVector(b, [m0]);
-    const camp = fb.BannerCampaign.createBannerCampaign(b, 3, msgs);
+    fb.BannerCampaign.startBannerCampaign(b);
+    fb.BannerCampaign.addWeight(b, 3);
+    fb.BannerCampaign.addMessages(b, msgs);
+    const camp = fb.BannerCampaign.endBannerCampaign(b);
     const camps = fb.BannerInfo.createCampaignsVector(b, [camp]);
     const banner = fb.BannerInfo.createBannerInfo(b, camps, 60000, 5000, 40, 1000, 250, 1000);
     fb.Profile.startProfile(b);
@@ -656,7 +660,8 @@ describe('codec', () => {
     b.finish(fb.Profile.endProfile(b));
 
     const p = decodeProfile(b.asUint8Array());
-    expect(p.banner?.campaigns).toEqual([{ weight: 3, messages: ['promo-en'] }]);
+    // A plain campaign carries no override (both sets null → the neutral theme tokens).
+    expect(p.banner?.campaigns).toEqual([{ weight: 3, messages: ['promo-en'], overrideAll: null, overrideDark: null }]);
     expect(p.banner?.timings).toEqual({
       holdMs: 60000,
       edgePauseMs: 5000,
@@ -667,6 +672,26 @@ describe('codec', () => {
     });
   });
 
+  it('decodes a campaign colour override (both sets)', () => {
+    const b = new Builder(256);
+    const uid = b.createString('u-1');
+    const m0 = b.createString('branded');
+    const msgs = fb.BannerCampaign.createMessagesVector(b, [m0]);
+    const s = (v: string) => b.createString(v);
+    const [obg, ofg, ol, obgd, ofgd, old] = ['#aa0000', '#ffffff', '#ffdd00', '#330000', '#eeeeee', '#ffcc00'].map(s);
+    const camp = fb.BannerCampaign.createBannerCampaign(b, 1, msgs, obg, ofg, ol, obgd, ofgd, old);
+    const camps = fb.BannerInfo.createCampaignsVector(b, [camp]);
+    const banner = fb.BannerInfo.createBannerInfo(b, camps, 60000, 5000, 40, 1000, 250, 1000);
+    fb.Profile.startProfile(b);
+    fb.Profile.addUserId(b, uid);
+    fb.Profile.addBanner(b, banner);
+    b.finish(fb.Profile.endProfile(b));
+
+    const p = decodeProfile(b.asUint8Array());
+    expect(p.banner?.campaigns[0].overrideAll).toEqual({ bg: '#aa0000', fg: '#ffffff', link: '#ffdd00' });
+    expect(p.banner?.campaigns[0].overrideDark).toEqual({ bg: '#330000', fg: '#eeeeee', link: '#ffcc00' });
+  });
+
   it('leaves the profile banner undefined when absent', () => {
     const b = new Builder(64);
     const uid = b.createString('u-1');
@@ -687,6 +712,28 @@ describe('codec', () => {
     expect(decodeProfile(b.asUint8Array()).variantPreferences).toEqual(['erudit_ru', 'scrabble_en']);
   });
 
+  it('decodes the profile dictionary versions into a per-variant map', () => {
+    const b = new Builder(128);
+    const uid = b.createString('u-1');
+    const en = fb.DictVersion.createDictVersion(b, b.createString('scrabble_en'), b.createString('v1.3.0'));
+    const er = fb.DictVersion.createDictVersion(b, b.createString('erudit_ru'), b.createString('v1.2.0'));
+    const vec = fb.Profile.createDictVersionsVector(b, [en, er]);
+    fb.Profile.startProfile(b);
+    fb.Profile.addUserId(b, uid);
+    fb.Profile.addDictVersions(b, vec);
+    b.finish(fb.Profile.endProfile(b));
+    expect(decodeProfile(b.asUint8Array()).dictVersions).toEqual({ scrabble_en: 'v1.3.0', erudit_ru: 'v1.2.0' });
+  });
+
+  it('decodes an absent dict_versions vector to an empty map', () => {
+    const b = new Builder(64);
+    const uid = b.createString('u-1');
+    fb.Profile.startProfile(b);
+    fb.Profile.addUserId(b, uid);
+    b.finish(fb.Profile.endProfile(b));
+    expect(decodeProfile(b.asUint8Array()).dictVersions).toEqual({});
+  });
+
   it('encodes the update-profile variant preferences', () => {
     const buf = encodeUpdateProfile({
       displayName: 'Kaya',

ui/src/lib/codec.ts

@@ -19,6 +19,7 @@ import type {
   BestMoveTile,
   BlockStatus,
   ChatMessage,
+  ColorTriple,
   EvalResult,
   FeedbackState,
   FriendCode,
@@ -213,7 +214,12 @@ export function encodeGuestLogin(locale: string, browserTz: string): Uint8Array
   return finish(b, fb.GuestLoginRequest.endGuestLoginRequest(b));
 }
 
-export function encodeEmailRequest(email: string, browserTz: string, language: string): Uint8Array {
+export function encodeEmailRequest(
+  email: string,
+  browserTz: string,
+  language: string,
+  pwa: boolean,
+): Uint8Array {
   const b = new Builder(128);
   const e = b.createString(email);
   const tz = b.createString(browserTz);
@@ -222,6 +228,7 @@ export function encodeEmailRequest(email: string, browserTz: string, language: s
   fb.EmailRequestRequest.addEmail(b, e);
   fb.EmailRequestRequest.addBrowserTz(b, tz);
   fb.EmailRequestRequest.addLanguage(b, l);
+  fb.EmailRequestRequest.addPwa(b, pwa);
   return finish(b, fb.EmailRequestRequest.endEmailRequestRequest(b));
 }
 
@@ -357,9 +364,25 @@ export function decodeProfile(buf: Uint8Array): Profile {
     email: s(p.email()),
     telegramLinked: p.telegramLinked(),
     vkLinked: p.vkLinked(),
+    dictVersions: decodeDictVersions(p),
   };
 }
 
+// decodeDictVersions reads the profile's per-variant current dictionary versions into a
+// variant-keyed map, so the offline preloader can look up the version for each enabled
+// variant. An entry with an unknown variant or empty version is skipped.
+function decodeDictVersions(p: fb.Profile): Partial<Record<Variant, string>> {
+  const out: Partial<Record<Variant, string>> = {};
+  for (let i = 0; i < p.dictVersionsLength(); i++) {
+    const dv = p.dictVersions(i);
+    if (!dv) continue;
+    const variant = s(dv.variant()) as Variant;
+    const version = s(dv.version());
+    if (variant && version) out[variant] = version;
+  }
+  return out;
+}
+
 // decodeVariantPreferences reads the Profile.variant_preferences vector (the variants
 // the player enabled in Settings).
 function decodeVariantPreferences(p: fb.Profile): Variant[] {
@@ -368,6 +391,12 @@ function decodeVariantPreferences(p: fb.Profile): Variant[] {
   return out;
 }
 
+// bannerTriple builds a colour override from the three wire fields, or null when the
+// set is absent (any field empty/missing) — the strip then keeps the neutral tokens.
+function bannerTriple(bg: string | null, fg: string | null, link: string | null): ColorTriple | null {
+  return bg && fg && link ? { bg, fg, link } : null;
+}
+
 // decodeBanner projects the optional advertising-banner block of a Profile, or
 // undefined when the viewer is not eligible (the field is absent).
 function decodeBanner(p: fb.Profile): Banner | undefined {
@@ -379,7 +408,12 @@ function decodeBanner(p: fb.Profile): Banner | undefined {
     if (!c) continue;
     const messages: string[] = [];
     for (let j = 0; j < c.messagesLength(); j++) messages.push(c.messages(j));
-    campaigns.push({ weight: c.weight(), messages });
+    campaigns.push({
+      weight: c.weight(),
+      messages,
+      overrideAll: bannerTriple(c.overrideBg(), c.overrideFg(), c.overrideLink()),
+      overrideDark: bannerTriple(c.overrideBgDark(), c.overrideFgDark(), c.overrideLinkDark()),
+    });
   }
   return {
     campaigns,
@@ -427,6 +461,7 @@ function decodeStateViewTable(v: fb.StateView): StateView {
     bagLen: v.bagLen(),
     hintsRemaining: v.hintsRemaining(),
     walletBalance: v.walletBalance(),
+    hintUnlockLeftSeconds: v.hintUnlockLeftSeconds(),
   };
 }
 

ui/src/lib/connection.svelte.ts

@@ -9,6 +9,7 @@
 // other traffic is in flight.
 
 import { backoffMs } from './retry';
+import { offlineMode } from './offline.svelte';
 
 let online = $state(true);
 let watchTimer: ReturnType<typeof setTimeout> | null = null;
@@ -27,6 +28,24 @@ export function registerProbe(fn: () => Promise<void>): void {
   probe = fn;
 }
 
+/**
+ * checkReachable runs the reachability probe once, bounded by timeoutMs, and reports whether the
+ * gateway answered — a single attempt (no retry loop), for the cold-start network decision — while
+ * updating the online signal. It reports false when no probe is registered or the timeout wins.
+ */
+export async function checkReachable(timeoutMs: number): Promise<boolean> {
+  if (!probe) return false;
+  try {
+    await Promise.race([
+      probe(),
+      new Promise<never>((_, reject) => setTimeout(() => reject(new Error('reachability timeout')), timeoutMs)),
+    ]);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 /** reportOnline marks the gateway reachable and stops the watcher. */
 export function reportOnline(): void {
   online = true;
@@ -51,7 +70,9 @@ function scheduleProbe(attempt: number): void {
   watchTimer = setTimeout(
     () => {
       watchTimer = null;
-      if (online || !probe) return;
+      // Never probe the network in offline mode (the kill switch); the online/offline events drive
+      // recovery there instead.
+      if (online || !probe || offlineMode.active) return;
       probe().then(reportOnline, () => scheduleProbe(Math.min(attempt + 1, 6)));
     },
     backoffMs(attempt),

ui/src/lib/dict/dawg.cursor.test.ts

@@ -0,0 +1,68 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { Dawg } from './dawg';
+
+// The step-by-step DAWG cursor (root/final/next/arcs) is the primitive the move
+// generator walks. These fast unit tests pin it against a small committed sample
+// dictionary (backend/cmd/movegen); the full parity vs the Go solver lands with
+// the generator's conformance fixtures.
+const bytes = new Uint8Array(readFileSync(new URL('./testdata/sample_en.dawg', import.meta.url)));
+const fixture = JSON.parse(
+  readFileSync(new URL('./testdata/sample_en.words.json', import.meta.url), 'utf8'),
+) as { numAdded: number; words: string[]; indexes: number[][] };
+
+const key = (w: number[]): string => w.join(',');
+
+// enumerateWords walks the whole automaton depth-first, collecting the index path
+// at every accepting node — i.e. every stored word.
+function enumerateWords(d: Dawg): number[][] {
+  const out: number[][] = [];
+  const path: number[] = [];
+  const visit = (node: number): void => {
+    d.arcs(node, (label, dest, final) => {
+      path.push(label);
+      if (final) out.push(path.slice());
+      visit(dest);
+      path.pop();
+      return true;
+    });
+  };
+  if (d.final(d.root())) out.push([]);
+  visit(d.root());
+  return out;
+}
+
+describe('dawg cursor', () => {
+  it('parses the sample fixture', () => {
+    const d = new Dawg(bytes);
+    expect(d.numAdded).toBe(fixture.numAdded);
+  });
+
+  it('root is not an accepting state (the sample has no empty word)', () => {
+    const d = new Dawg(bytes);
+    expect(d.final(d.root())).toBe(false);
+  });
+
+  it('enumerates exactly the stored words', () => {
+    const d = new Dawg(bytes);
+    const got = enumerateWords(d).map(key).sort();
+    const want = fixture.indexes.map(key).sort();
+    expect(got).toEqual(want);
+  });
+
+  it('next walks a stored word to an accepting node and rejects a non-edge', () => {
+    const d = new Dawg(bytes);
+    let node = d.root();
+    for (const ch of [2, 0, 17, 4, 3]) {
+      // "cared"
+      node = d.next(node, ch);
+      expect(node).toBeGreaterThanOrEqual(0);
+    }
+    expect(d.final(node)).toBe(true);
+    // "care" (index [2,0,17,4]) is an internal accepting node on the way to "cared".
+    const care = [2, 0, 17, 4].reduce((n, ch) => d.next(n, ch), d.root());
+    expect(d.final(care)).toBe(true);
+    // No stored word starts with 'z' (index 25).
+    expect(d.next(d.root(), 25)).toBe(-1);
+  });
+});

ui/src/lib/dict/dawg.ts

@@ -95,6 +95,85 @@ export class Dawg {
     return this.indexOf(word) >= 0;
   }
 
+  // --- Step-by-step traversal (the move generator's primitive) ---------------
+  //
+  // A `Node` is a bit offset into the graph; 0 denotes the root (which resolves
+  // to firstNodeOffset). These mirror dafsa's traverse.go Cursor (Root/Final/
+  // Next/Arcs) over the same bitstream this reader already decodes, so the ported
+  // generator can drive the automaton one transition at a time. Single-threaded
+  // JS shares this reader's position across calls; every method re-seeks to its
+  // node on entry, and arcs brackets the callback with a save/restore, so nested
+  // use during a walk is safe. Mirrors dafsa (*Cursor).
+
+  /** root returns the start state of the automaton. */
+  root(): number {
+    return 0;
+  }
+
+  /** final reports whether node is an accepting state (a stored word ends there). */
+  final(node: number): boolean {
+    if (this.numEdges <= 0) {
+      return this.hasEmptyWord && node === 0;
+    }
+    this.p = node === 0 ? this.firstNodeOffset : node;
+    return this.readBits(1) === 1;
+  }
+
+  /**
+   * next follows the edge labelled ch (an alphabet index) from node, returning the
+   * destination node, or -1 when no such edge exists.
+   */
+  next(node: number, ch: number): number {
+    return this.getEdge(node, ch) ? this.eNode : -1;
+  }
+
+  /**
+   * arcs calls fn for each out-edge of node in ascending label order, passing the
+   * edge's label, its destination node and whether that destination is accepting.
+   * It stops early if fn returns false. Mirrors dafsa (*Cursor).Arcs.
+   */
+  arcs(node: number, fn: (label: number, dest: number, final: boolean) => boolean): void {
+    if (this.numEdges <= 0) {
+      return;
+    }
+    this.p = node === 0 ? this.firstNodeOffset : node;
+    this.readBits(1); // node final flag — not needed here
+    const fallthrough = this.readBits(1);
+
+    if (fallthrough === 1) {
+      const label = this.readBits(this.cbits);
+      // The reader now sits at the destination node, whose first bit is its final flag.
+      const dest = this.p;
+      const final = this.readBits(1) === 1;
+      fn(label, dest, final);
+      return;
+    }
+
+    const nskiplen = bitsLen(this.wbits);
+    let nskip = 0;
+    let numEdges = 1;
+    if (this.readBits(1) !== 1) {
+      // not a single edge
+      numEdges = this.readUnsigned();
+      nskip = this.readBits(nskiplen);
+    }
+
+    for (let i = 0; i < numEdges; i++) {
+      const label = this.readBits(this.cbits);
+      if (i > 0) {
+        this.readBits(nskip); // per-edge skip count, unused for traversal
+      }
+      const dest = this.readBits(this.abits);
+      const resume = this.p;
+      this.p = dest;
+      const final = this.readBits(1) === 1;
+      if (!fn(label, dest, final)) {
+        return;
+      }
+      this.p = resume;
+    }
+  }
+
   // getEdge resolves the outgoing edge for ch from the node at the given bit
   // offset. On success it fills eNode/eCount/eFinal and returns true. Mirrors
   // dafsa (*dawg).getEdge.

ui/src/lib/dict/generate.parity.test.ts

@@ -0,0 +1,99 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { Dawg } from './dawg';
+import { generateMoves, GenRack, type GenBoard, type Mode } from './generate';
+import type { Ruleset } from './validate';
+
+// Conformance gate for the ported move generator: for each committed position it must
+// return exactly the ranked play list the real Go solver returns (backend/cmd/movegen).
+// The Russian sample reaches alphabet index 32, exercising the 33-letter cross-set.
+
+interface Tile {
+  row: number;
+  col: number;
+  letter: number;
+  blank: boolean;
+}
+interface GenMove {
+  dir: number;
+  tiles: Tile[];
+  score: number;
+}
+interface Fixture {
+  ruleset: {
+    size: number;
+    cols: number;
+    center: number;
+    rackSize: number;
+    bingo: number;
+    values: number[];
+    letterMult: number[][];
+    wordMult: number[][];
+  };
+  cases: {
+    name: string;
+    placed: Tile[] | null;
+    rack: { letters: number[]; blanks: number };
+    mode: number;
+    ignoreCrossWords: boolean;
+    moves: GenMove[];
+  }[];
+}
+
+function load(tag: string): { dawg: Dawg; fx: Fixture } {
+  const bytes = new Uint8Array(readFileSync(new URL(`./testdata/sample_${tag}.dawg`, import.meta.url)));
+  const fx = JSON.parse(
+    readFileSync(new URL(`./testdata/sample_${tag}.gen.json`, import.meta.url), 'utf8'),
+  ) as Fixture;
+  return { dawg: new Dawg(bytes), fx };
+}
+
+function buildBoard(placed: Tile[], cols: number): GenBoard {
+  const grid: ({ letter: number; blank: boolean } | null)[] = new Array(cols * cols).fill(null);
+  for (const t of placed) grid[t.row * cols + t.col] = { letter: t.letter, blank: t.blank };
+  const inBounds = (r: number, c: number): boolean => r >= 0 && r < cols && c >= 0 && c < cols;
+  return {
+    rows: cols,
+    cols,
+    inBounds,
+    filled: (r, c) => inBounds(r, c) && grid[r * cols + c] !== null,
+    cellAt: (r, c) => grid[r * cols + c]!,
+    isEmpty: () => placed.length === 0,
+  };
+}
+
+function rulesetFor(fx: Fixture, ignoreCrossWords: boolean): Ruleset {
+  const r = fx.ruleset;
+  return {
+    cols: r.cols,
+    center: r.center,
+    rackSize: r.rackSize,
+    bingo: r.bingo,
+    values: r.values,
+    letterMult: (row, col) => r.letterMult[row][col],
+    wordMult: (row, col) => r.wordMult[row][col],
+    ignoreCrossWords,
+  };
+}
+
+// sig is an order-stable signature of a move: orientation, score and its placed tiles
+// sorted by square — so two lists compare equal iff they rank the same plays the same way.
+function sig(m: GenMove): string {
+  const ts = m.tiles.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  return `${m.dir}#${m.score}#` + ts.map((t) => `${t.row},${t.col},${t.letter}${t.blank ? '*' : ''}`).join(';');
+}
+
+for (const tag of ['en', 'ru']) {
+  describe(`move generator parity vs Go solver (${tag})`, () => {
+    const { dawg, fx } = load(tag);
+    for (const c of fx.cases) {
+      it(c.name, () => {
+        const board = buildBoard(c.placed ?? [], fx.ruleset.cols);
+        const rack = GenRack.from(fx.ruleset.size, c.rack.letters, c.rack.blanks);
+        const rs = rulesetFor(fx, c.ignoreCrossWords);
+        const got = generateMoves(dawg, board, rack, rs, c.mode as Mode);
+        expect(got.map(sig)).toEqual(c.moves.map(sig));
+      });
+    }
+  });
+}

ui/src/lib/dict/generate.realparity.test.ts

@@ -0,0 +1,113 @@
+import { describe, it, expect } from 'vitest';
+import { readFileSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
+import { Dawg } from './dawg';
+import { generateMoves, GenRack, type GenBoard, type Mode } from './generate';
+import type { Ruleset } from './validate';
+
+// Full-dictionary conformance for the ported move generator: for positions over the real
+// shipped dictionaries (deep graphs and full 26/33-letter alphabets the tiny committed
+// samples cannot reach) it must return exactly the ranked list the Go solver does. The
+// golden vectors come from `go run ./backend/cmd/movegen -dawg-dir <dawg> -out <dir>` and
+// the CI conformance job wires the two directories in; the suite skips when they are unset.
+const dawgDir = process.env.DICT_DAWG_DIR;
+const goldDir = process.env.DICT_MOVEGEN_DIR;
+const ready = !!dawgDir && !!goldDir && existsSync(dawgDir) && existsSync(goldDir);
+
+// variant -> the release dawg file name (matches dawg.parity.test.ts / the movegen tool).
+const variants = [
+  { variant: 'scrabble_en', dawg: 'en_sowpods' },
+  { variant: 'scrabble_ru', dawg: 'ru_scrabble' },
+  { variant: 'erudit_ru', dawg: 'ru_erudit' },
+];
+
+interface Tile {
+  row: number;
+  col: number;
+  letter: number;
+  blank: boolean;
+}
+interface GenMove {
+  dir: number;
+  tiles: Tile[];
+  score: number;
+}
+interface Fixture {
+  ruleset: {
+    size: number;
+    cols: number;
+    center: number;
+    rackSize: number;
+    bingo: number;
+    values: number[];
+    letterMult: number[][];
+    wordMult: number[][];
+  };
+  cases: {
+    name: string;
+    placed: Tile[] | null;
+    rack: { letters: number[]; blanks: number };
+    mode: number;
+    ignoreCrossWords: boolean;
+    moves: GenMove[];
+  }[];
+}
+
+function buildBoard(placed: Tile[], cols: number): GenBoard {
+  const grid: ({ letter: number; blank: boolean } | null)[] = new Array(cols * cols).fill(null);
+  for (const t of placed) grid[t.row * cols + t.col] = { letter: t.letter, blank: t.blank };
+  const inBounds = (r: number, c: number): boolean => r >= 0 && r < cols && c >= 0 && c < cols;
+  return {
+    rows: cols,
+    cols,
+    inBounds,
+    filled: (r, c) => inBounds(r, c) && grid[r * cols + c] !== null,
+    cellAt: (r, c) => grid[r * cols + c]!,
+    isEmpty: () => placed.length === 0,
+  };
+}
+
+function rulesetFor(fx: Fixture, ignoreCrossWords: boolean): Ruleset {
+  const r = fx.ruleset;
+  return {
+    cols: r.cols,
+    center: r.center,
+    rackSize: r.rackSize,
+    bingo: r.bingo,
+    values: r.values,
+    letterMult: (row, col) => r.letterMult[row][col],
+    wordMult: (row, col) => r.wordMult[row][col],
+    ignoreCrossWords,
+  };
+}
+
+function sig(m: GenMove): string {
+  const ts = m.tiles.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  return `${m.dir}#${m.score}#` + ts.map((t) => `${t.row},${t.col},${t.letter}${t.blank ? '*' : ''}`).join(';');
+}
+
+describe.skipIf(!ready)('move generator parity vs Go on the real dictionaries', () => {
+  for (const v of variants) {
+    describe(v.variant, () => {
+      // Guard the collection-time reads: the block is skipped when the dirs are unset, but
+      // the describe callback still runs to register tests, so touch the filesystem only
+      // when ready (otherwise join(undefined, …) would throw during a normal unit run).
+      if (!ready) return;
+      const fx = JSON.parse(readFileSync(join(goldDir!, `${v.variant}.movegen.json`), 'utf8')) as Fixture;
+      const dawg = new Dawg(new Uint8Array(readFileSync(join(dawgDir!, `${v.dawg}.dawg`))));
+      for (const c of fx.cases) {
+        it(
+          c.name,
+          () => {
+            const board = buildBoard(c.placed ?? [], fx.ruleset.cols);
+            const rack = GenRack.from(fx.ruleset.size, c.rack.letters, c.rack.blanks);
+            const rs = rulesetFor(fx, c.ignoreCrossWords);
+            const got = generateMoves(dawg, board, rack, rs, c.mode as Mode);
+            expect(got.map(sig)).toEqual(c.moves.map(sig));
+          },
+          60_000,
+        );
+      }
+    });
+  }
+});

ui/src/lib/dict/generate.ts

@@ -0,0 +1,418 @@
+// Local move generator: every legal play for a rack on a board, ranked by
+// descending score. Ported from the scrabble-solver engine — the Appel-Jacobson
+// two-phase algorithm (LeftPart then ExtendRight) over a plain left-to-right DAWG
+// (scrabble/gen_dawg.go, gen.go, crossset.go, solver.go, key.go). It walks the DAWG
+// with the cursor from dawg.ts and scores each play with evaluate() from validate.ts,
+// so the whole robot brain runs on-device. Faithfulness to the Go solver is pinned by
+// generate.parity.test.ts against golden fixtures (backend/cmd/movegen).
+//
+// Everything works in alphabet-index space, mirroring the Go engine. A letterSet is
+// a per-square cross-set (the letters that form a legal perpendicular word there);
+// it is a boolean membership array rather than a uint64, so alphabet indexes past
+// JS's 31-bit shift boundary (Russian has 33 letters) are handled exactly.
+
+import { Dawg } from './dawg';
+import {
+  evaluate,
+  connected,
+  Horizontal,
+  Vertical,
+  type Board,
+  type Ruleset,
+  type Move,
+  type Placement,
+  type Direction,
+} from './validate';
+
+/** Both generates across plays (on the board) and down plays (on its transpose). */
+export const Both = 0;
+/** OnlyHorizontal generates across plays only. */
+export const OnlyHorizontal = 1;
+/** OnlyVertical generates down plays only (Эрудит plays a single orientation per turn). */
+export const OnlyVertical = 2;
+export type Mode = typeof Both | typeof OnlyHorizontal | typeof OnlyVertical;
+
+function modeIncludes(mode: Mode, dir: Direction): boolean {
+  if (mode === Both) return true;
+  if (mode === OnlyHorizontal) return dir === Horizontal;
+  return dir === Vertical;
+}
+
+/**
+ * GenBoard is the board view the generator needs: the validator's read view plus the
+ * dimensions it iterates over. The whole board is square, so a transposed view (below)
+ * satisfies the same shape.
+ */
+export interface GenBoard extends Board {
+  rows: number;
+  cols: number;
+}
+
+/**
+ * GenRack is a rack as per-letter tile counts plus a blank slot, mirroring
+ * scrabble-solver/rack. The generator mutates a single rack in place — removing a
+ * tile, recursing, putting it back — so the operations are O(1) and allocation-free.
+ */
+export class GenRack {
+  private readonly counts: Int32Array;
+
+  /** Construct an empty rack for an alphabet of the given size (a trailing blank slot). */
+  constructor(size: number) {
+    this.counts = new Int32Array(size + 1);
+  }
+
+  /** from builds a rack from a multiset of letter indexes plus a blank count. */
+  static from(size: number, letters: readonly number[], blanks: number): GenRack {
+    const r = new GenRack(size);
+    for (const l of letters) r.counts[l]++;
+    r.counts[size] += blanks;
+    return r;
+  }
+
+  /** has reports whether at least one tile of the letter index is on the rack. */
+  has(letter: number): boolean {
+    return this.counts[letter] > 0;
+  }
+  /** blanks returns how many blank tiles are on the rack. */
+  blanks(): number {
+    return this.counts[this.counts.length - 1];
+  }
+  remove(letter: number): void {
+    this.counts[letter]--;
+  }
+  add(letter: number): void {
+    this.counts[letter]++;
+  }
+  removeBlank(): void {
+    this.counts[this.counts.length - 1]--;
+  }
+  addBlank(): void {
+    this.counts[this.counts.length - 1]++;
+  }
+  /** clone returns an independent copy. */
+  clone(): GenRack {
+    const c = new GenRack(this.counts.length - 1);
+    c.counts.set(this.counts);
+    return c;
+  }
+}
+
+// --- cross-sets ------------------------------------------------------------------
+//
+// A LetterSet is membership over alphabet letter indexes. Mirrors scrabble.letterSet
+// (a uint64) but as a Uint8Array so index 32 (Russian) is exact under JS bit ops.
+type LetterSet = Uint8Array;
+
+function fullSet(size: number): LetterSet {
+  return new Uint8Array(size).fill(1);
+}
+
+// walk follows word (alphabet indexes) left to right from the root; -1 if it derails.
+function walk(dawg: Dawg, word: readonly number[]): number {
+  let n = dawg.root();
+  for (const l of word) {
+    n = dawg.next(n, l);
+    if (n < 0) return -1;
+  }
+  return n;
+}
+
+// completers returns the letters X (< size) whose arc from state leads directly to an
+// accepting node — the deterministic cross-set primitive. Mirrors scrabble.completers.
+function completers(dawg: Dawg, state: number, size: number): LetterSet {
+  const set = new Uint8Array(size);
+  dawg.arcs(state, (label, _dest, final) => {
+    if (final && label < size) set[label] = 1;
+    return true;
+  });
+  return set;
+}
+
+// dawgCrossSet returns the letters X for which above·X·below is a stored word. Mirrors
+// scrabble.dawgCrossSet: a right extension (no tiles below) just completes the prefix
+// above; a left extension (tiles below) probes each X. above/below are letter indexes.
+function dawgCrossSet(dawg: Dawg, above: number[], below: number[], size: number): LetterSet {
+  if (above.length === 0 && below.length === 0) return fullSet(size);
+  if (below.length === 0) {
+    const node = walk(dawg, above);
+    if (node < 0) return new Uint8Array(size);
+    return completers(dawg, node, size);
+  }
+  let node = dawg.root();
+  if (above.length > 0) {
+    node = walk(dawg, above);
+    if (node < 0) return new Uint8Array(size);
+  }
+  const set = new Uint8Array(size);
+  for (let x = 0; x < size; x++) {
+    let m = dawg.next(node, x);
+    if (m < 0) continue;
+    let ok = true;
+    for (const l of below) {
+      m = dawg.next(m, l);
+      if (m < 0) {
+        ok = false;
+        break;
+      }
+    }
+    if (ok && dawg.final(m)) set[x] = 1;
+  }
+  return set;
+}
+
+// columnContext returns the contiguous run of filled cells immediately above and below
+// the empty square (r, c), each top to bottom, as letter indexes — the tiles a
+// perpendicular word through (r, c) would include. Mirrors scrabble.columnContext.
+function columnContext(b: GenBoard, r: number, c: number): { above: number[]; below: number[] } {
+  const above: number[] = [];
+  let start = r;
+  while (start - 1 >= 0 && b.filled(start - 1, c)) start--;
+  for (let rr = start; rr < r; rr++) above.push(b.cellAt(rr, c).letter);
+
+  const below: number[] = [];
+  let end = r;
+  while (end + 1 < b.rows && b.filled(end + 1, c)) end++;
+  for (let rr = r + 1; rr <= end; rr++) below.push(b.cellAt(rr, c).letter);
+  return { above, below };
+}
+
+// transpose returns a view of b with rows and columns swapped, so down-play generation
+// runs as across generation. Mirrors board.Transpose (as a lazy view).
+function transpose(b: GenBoard): GenBoard {
+  return {
+    rows: b.cols,
+    cols: b.rows,
+    inBounds: (r, c) => b.inBounds(c, r),
+    filled: (r, c) => b.filled(c, r),
+    cellAt: (r, c) => b.cellAt(c, r),
+    isEmpty: () => b.isEmpty(),
+  };
+}
+
+// A tentatively placed left-part tile; its column is fixed only at record time.
+interface TileInfo {
+  letter: number;
+  blank: boolean;
+}
+
+// AcrossGen carries one across-generation pass over a board. Mirrors scrabble.acrossGen.
+class AcrossGen {
+  private row = 0;
+  private readonly left: TileInfo[] = [];
+  private readonly right: Placement[] = [];
+
+  constructor(
+    private readonly dawg: Dawg,
+    private readonly bd: GenBoard,
+    private readonly rk: GenRack,
+    private readonly cross: (r: number, c: number) => LetterSet,
+    private readonly emit: (placements: Placement[]) => void,
+  ) {}
+
+  generateRow(row: number, firstMove: boolean, centerRow: number, centerCol: number): void {
+    this.row = row;
+    let limit = 0;
+    for (let col = 0; col < this.bd.cols; col++) {
+      if (this.bd.filled(row, col)) {
+        limit = 0;
+        continue;
+      }
+      const anchor = firstMove ? row === centerRow && col === centerCol : this.hasFilledNeighbor(row, col);
+      if (!anchor) {
+        limit++;
+        continue;
+      }
+      this.left.length = 0;
+      this.right.length = 0;
+      if (col > 0 && this.bd.filled(row, col - 1)) {
+        const pre = this.walkPrefix(row, col);
+        if (pre.ok) this.extendRight(pre.node, col, col);
+      } else {
+        this.leftPart(this.dawg.root(), col, limit);
+      }
+      limit = 0;
+    }
+  }
+
+  private hasFilledNeighbor(r: number, c: number): boolean {
+    return this.bd.filled(r - 1, c) || this.bd.filled(r + 1, c) || this.bd.filled(r, c - 1) || this.bd.filled(r, c + 1);
+  }
+
+  // walkPrefix walks the DAWG through the filled run ending at col-1, returning the
+  // node reached and whether that prefix exists. Mirrors scrabble.acrossGen.walkPrefix.
+  private walkPrefix(row: number, col: number): { node: number; ok: boolean } {
+    let start = col - 1;
+    while (start - 1 >= 0 && this.bd.filled(row, start - 1)) start--;
+    let node = this.dawg.root();
+    for (let c = start; c < col; c++) {
+      node = this.dawg.next(node, this.bd.cellAt(row, c).letter);
+      if (node < 0) return { node, ok: false };
+    }
+    return { node, ok: true };
+  }
+
+  // leftPart places left-part tiles from the rack (up to limit), calling extendRight
+  // after each prefix. Mirrors scrabble.acrossGen.leftPart.
+  private leftPart(node: number, anchorCol: number, limit: number): void {
+    this.extendRight(node, anchorCol, anchorCol);
+    if (limit === 0) return;
+    this.dawg.arcs(node, (label, dest) => {
+      if (this.rk.has(label)) {
+        this.rk.remove(label);
+        this.left.push({ letter: label, blank: false });
+        this.leftPart(dest, anchorCol, limit - 1);
+        this.left.pop();
+        this.rk.add(label);
+      }
+      if (this.rk.blanks() > 0) {
+        this.rk.removeBlank();
+        this.left.push({ letter: label, blank: true });
+        this.leftPart(dest, anchorCol, limit - 1);
+        this.left.pop();
+        this.rk.addBlank();
+      }
+      return true;
+    });
+  }
+
+  // extendRight extends the word rightward from col, placing rack tiles on empty
+  // squares (constrained by cross-sets) and following board tiles. A word is recorded
+  // only past the anchor. Mirrors scrabble.acrossGen.extendRight.
+  private extendRight(node: number, col: number, anchorCol: number): void {
+    if (col >= this.bd.cols) {
+      if (col > anchorCol && this.dawg.final(node)) this.record(anchorCol);
+      return;
+    }
+    if (this.bd.filled(this.row, col)) {
+      const dest = this.dawg.next(node, this.bd.cellAt(this.row, col).letter);
+      if (dest >= 0) this.extendRight(dest, col + 1, anchorCol);
+      return;
+    }
+
+    if (col > anchorCol && this.dawg.final(node)) this.record(anchorCol);
+    const cross = this.cross(this.row, col);
+    this.dawg.arcs(node, (label, dest) => {
+      if (cross[label] !== 1) return true;
+      if (this.rk.has(label)) {
+        this.rk.remove(label);
+        this.right.push({ row: this.row, col, letter: label, blank: false });
+        this.extendRight(dest, col + 1, anchorCol);
+        this.right.pop();
+        this.rk.add(label);
+      }
+      if (this.rk.blanks() > 0) {
+        this.rk.removeBlank();
+        this.right.push({ row: this.row, col, letter: label, blank: true });
+        this.extendRight(dest, col + 1, anchorCol);
+        this.right.pop();
+        this.rk.addBlank();
+      }
+      return true;
+    });
+  }
+
+  // record assembles the play (left part at fixed columns, then the right part) and
+  // reports it, skipping plays that lay no new tile. Mirrors scrabble.acrossGen.record.
+  private record(anchorCol: number): void {
+    if (this.left.length + this.right.length === 0) return;
+    const placements: Placement[] = [];
+    const leftStart = anchorCol - this.left.length;
+    for (let i = 0; i < this.left.length; i++) {
+      placements.push({ row: this.row, col: leftStart + i, letter: this.left[i].letter, blank: this.left[i].blank });
+    }
+    for (const p of this.right) placements.push(p);
+    this.emit(placements);
+  }
+}
+
+// runAcross generates all across plays on bd and reports each via emit in bd's
+// coordinates. Cross-sets are computed lazily (vertical words on bd) and cached.
+// Mirrors DAWGGenerator.runAcross.
+function runAcross(
+  dawg: Dawg,
+  bd: GenBoard,
+  rk: GenRack,
+  size: number,
+  rs: Ruleset,
+  centerRow: number,
+  centerCol: number,
+  emit: (placements: Placement[]) => void,
+): void {
+  let crossFn: (r: number, c: number) => LetterSet;
+  if (rs.ignoreCrossWords) {
+    const full = fullSet(size);
+    crossFn = () => full;
+  } else {
+    const cache = new Array<LetterSet | undefined>(bd.rows * bd.cols);
+    crossFn = (r, c) => {
+      const i = r * bd.cols + c;
+      let s = cache[i];
+      if (!s) {
+        const { above, below } = columnContext(bd, r, c);
+        s = dawgCrossSet(dawg, above, below, size);
+        cache[i] = s;
+      }
+      return s;
+    };
+  }
+
+  const ag = new AcrossGen(dawg, bd, rk, crossFn, emit);
+  const firstMove = bd.isEmpty();
+  for (let row = 0; row < bd.rows; row++) {
+    ag.generateRow(row, firstMove, centerRow, centerCol);
+  }
+}
+
+// moveKey is a canonical string identifying a play (direction plus its placed tiles),
+// used to de-duplicate and rank generated moves. Mirrors scrabble.moveKey.
+export function moveKey(dir: Direction, placements: readonly Placement[]): string {
+  const ps = placements.slice().sort((a, b) => (a.row !== b.row ? a.row - b.row : a.col - b.col));
+  let s = String(dir);
+  for (const p of ps) s += `;${p.row},${p.col},${p.letter}${p.blank ? '*' : ''}`;
+  return s;
+}
+
+/**
+ * generateMoves returns every legal play for rack on board in the mode's orientations,
+ * ranked by descending score (ties broken by the canonical move key). It walks the DAWG
+ * with the cursor and scores each play with evaluate(); the alphabet size is taken from
+ * the ruleset's value table. Mirrors (*Solver).GenerateMovesOpts (the ruleset carries
+ * ignoreCrossWords for the single-word rule).
+ */
+export function generateMoves(dawg: Dawg, board: GenBoard, rack: GenRack, rs: Ruleset, mode: Mode = Both): Move[] {
+  const size = rs.values.length;
+  const rk = rack.clone(); // generation mutates the rack in place and restores it
+  const centerRow = Math.floor(rs.center / rs.cols);
+  const centerCol = rs.center % rs.cols;
+
+  const moves: Move[] = [];
+  const seen = new Set<string>();
+  const emit = (dir: Direction, placements: Placement[]): void => {
+    const key = moveKey(dir, placements);
+    if (seen.has(key)) return;
+    const res = evaluate(board, rs, dir, placements);
+    if (res.err || !res.move) return;
+    seen.add(key);
+    moves.push(res.move);
+  };
+
+  if (modeIncludes(mode, Horizontal)) {
+    runAcross(dawg, board, rk, size, rs, centerRow, centerCol, (p) => emit(Horizontal, p));
+  }
+  if (modeIncludes(mode, Vertical)) {
+    const tb = transpose(board);
+    runAcross(dawg, tb, rk, size, rs, centerCol, centerRow, (p) => {
+      const rp = p.map((pl) => ({ row: pl.col, col: pl.row, letter: pl.letter, blank: pl.blank }));
+      emit(Vertical, rp);
+    });
+  }
+
+  const kept = moves.filter((m) => connected(board, rs, m));
+  kept.sort((a, b) => {
+    if (a.score !== b.score) return b.score - a.score;
+    const ka = moveKey(a.dir, a.tiles);
+    const kb = moveKey(b.dir, b.tiles);
+    return ka < kb ? -1 : ka > kb ? 1 : 0;
+  });
+  return kept;
+}