Merge pull request 'native polish 2: two-robots fix, guest offline-host UX, Guest###### name, silent+fast native boot, minSdk 29' (#275) from feature/native-polish-2 into development

The bundled WebView build is only compatible from Android 10 (API 29); on Android 9 it lands on
the in-app unsupported-engine screen. Declaring minSdk 29 lets RuStore/Google Play block older
devices at install rather than shipping a known-incompatible build.

.gitea/workflows/android-build.yaml

@@ -3,7 +3,7 @@
 # a PR. It builds the native-flavoured SPA, bundles the offline dictionaries into the APK assets, and
 # assembles a release APK, uploaded as a run artifact (RuStore upload stays manual for the MVP).
 #
-# Signing degrades gracefully: with the ANDROID_KEYSTORE_* secrets present the APK is signed; without
+# Signing degrades gracefully: with the ANDROID_RUSTORE_* secrets present the APK is signed; without
 # them build.gradle produces an UNSIGNED release APK (so a dry run still proves the whole pipeline).
 # The keystore is a publication prerequisite — see deploy/README.md (Android build/release runbook).
 # The toolchain is self-provisioned here (JDK 21 + a cached Android SDK), so the runner host needs
@@ -144,7 +144,7 @@ jobs:
       - name: Decode the release keystore
         id: keystore
         env:
-          ANDROID_KEYSTORE_BASE64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
+          ANDROID_KEYSTORE_BASE64: ${{ secrets.ANDROID_RUSTORE_KEYSTORE_BASE64 }}
         run: |
           if [ -n "$ANDROID_KEYSTORE_BASE64" ]; then
             printf '%s' "$ANDROID_KEYSTORE_BASE64" | base64 -d > "${GITHUB_WORKSPACE}/release.jks"
@@ -152,16 +152,16 @@ jobs:
             echo "keystore decoded -> signed release build"
           else
             echo "file=" >> "$GITHUB_OUTPUT"
-            echo "::warning::ANDROID_KEYSTORE_BASE64 is not set — building an UNSIGNED release APK (not installable/publishable)"
+            echo "::warning::ANDROID_RUSTORE_KEYSTORE_BASE64 secret is not set — building an UNSIGNED release APK (not installable/publishable)"
           fi
 
       - name: Assemble the release APK
         working-directory: ui/android
         env:
           ANDROID_KEYSTORE_FILE: ${{ steps.keystore.outputs.file }}
-          ANDROID_KEYSTORE_PASSWORD: ${{ secrets.ANDROID_KEYSTORE_PASSWORD }}
+          ANDROID_KEYSTORE_PASSWORD: ${{ secrets.ANDROID_RUSTORE_KEYSTORE_PASSWORD }}
-          ANDROID_KEY_ALIAS: ${{ secrets.ANDROID_KEY_ALIAS }}
+          ANDROID_KEY_ALIAS: ${{ secrets.ANDROID_RUSTORE_KEY_ALIAS }}
-          ANDROID_KEY_PASSWORD: ${{ secrets.ANDROID_KEY_PASSWORD }}
+          ANDROID_KEY_PASSWORD: ${{ secrets.ANDROID_RUSTORE_KEY_PASSWORD }}
         run: ./gradlew assembleRelease -PversionCode=${{ steps.prep.outputs.code }} -PversionName=${{ steps.prep.outputs.name }} --console=plain
 
       - name: Upload the APK artifact

ANDROID_PLAN.md

@@ -62,19 +62,20 @@ client-only (no server change).
 
 Kept current as parts land so a fresh session resumes without re-deriving. Verify against code.
 
-> ### ▶ RESUME HERE — 2026-07-13 (documents track + release-prep)
+> ### ▶ RESUME HERE — 2026-07-14 (keystore secrets set; payments landed; gate = RuStore account + merge/tag)
 >
-> **Where we are.** The legal-documents track, the release-prep hygiene, **and the icon rebrand** are
+> **Where we are.** The legal-documents track, the release-prep hygiene, the icon rebrand **and the
-> DONE. The RuStore release is now gated on **owner-side** items only (keystore, RuStore account) plus
+> release keystore** are DONE (the keystore + its Gitea secrets set by the owner — see below). The
-> the merge/tag chain. Do not re-do or re-litigate the finished work; do not re-ask the locked decisions.
+> RuStore MVP is now gated on **one owner-side item** — the **RuStore developer account** (owner going
+> ИП; RuStore updated its requirements) — plus the agent's **promote/tag → signed-build** chain. Also
+> landed on `development` since: the payments **E10 multi-shop split** (#266) + **E11 kill switch**
+> (#267), both dormant / fail-open (no bearing on the Android build), and the signing-secret rename
+> `ANDROID_*` → **`ANDROID_RUSTORE_*`** (#268). Do not re-do the finished work or re-ask the locked
+> decisions.
 >
-> **Branches / PRs (current working branch: `feature/android-release-prep`).**
+> **Branches / PRs.** All merged to `development` (contour-green): legal documents (#253); release-prep
-> - `development` — has the **legal-documents track**, merged via **PR #253** (green, deployed to the
+> hygiene + the re-enabled `android-build` workflow (#254); the payments E10/E11 (#266/#267); the
->   test contour). `/privacy/`, `/eula/`, `/offer/` are live there, bilingual RU/EN.
+> signing-secret rename (#268). No open Android branch.
-> - `feature/android-release-prep` — the **release-prep hygiene**, **PR #254 OPEN, green, NOT merged**
->   (the owner chose to hold the merge). It is branched off `development`, so it also contains the
->   legal-documents track. Merge #254 into `development` when ready — needs **owner approval** (the
->   agent cannot self-approve).
 >
 > **Done this session.**
 > - **Legal documents** (satisfies the RuStore *hosted privacy-policy URL* prerequisite): authored
@@ -113,12 +114,12 @@ Kept current as parts land so a fresh session resumes without re-deriving. Verif
 > 2. **Merge PR #254** → `development` (owner approval), then **promote `development` → `master`** and
 >    **tag `vX.Y.Z`** for the release (the version stamps the APK `versionName`/`versionCode` and the
 >    `X-Client-Version` header).
-> 3. **Release keystore.** OWNER generates it (`keytool -genkeypair -v -keystore erudit-release.jks
+> 3. **Release keystore — DONE (owner, 2026-07-14).** `erudit-release.jks` (RSA 4096, alias `erudit`,
->    -alias erudit -keyalg RSA -keysize 4096 -validity 10000`), base64-encodes it, sets the four Gitea
+>    PKCS12) generated + backed up off-host; the four Gitea secrets are set under the RuStore-specific
->    **secrets** `ANDROID_KEYSTORE_BASE64` / `ANDROID_KEYSTORE_PASSWORD` / `ANDROID_KEY_ALIAS` /
+>    names `ANDROID_RUSTORE_KEYSTORE_BASE64` / `ANDROID_RUSTORE_KEYSTORE_PASSWORD` /
->    `ANDROID_KEY_PASSWORD`, and backs the `.jks` up **off-host** (loss ⇒ the app can never be updated).
+>    `ANDROID_RUSTORE_KEY_ALIAS` / `ANDROID_RUSTORE_KEY_PASSWORD` (loss ⇒ the app can never be updated —
->    The AGENT provides the exact commands on request. Without the secrets the workflow builds an
+>    the cert is pinned at the first RuStore upload). Google Play, later, would use its own
->    UNSIGNED APK (a dry run still proves the pipeline).
+>    `ANDROID_PLAY_*` upload key (Play App Signing) — a separate key.
 > 4. **RuStore developer account.** OWNER (verified legal entity or self-employed / самозанятый). Gates
 >    publication, not the build.
 > 5. **Dispatch the signed build.** AGENT: on `master`, dispatch `android-build` (`confirm=build`) via
@@ -132,6 +133,16 @@ Kept current as parts land so a fresh session resumes without re-deriving. Verif
 > 8. **Upload to RuStore.** OWNER. After publication, set the `ANDROID_RUSTORE_URL` Gitea variable to
 >    the store deep-link so the update button works on future gated releases (empty until then — the
 >    gate is dormant in the MVP).
+>
+> **Next tracks (design in a future session — interview the owner first).**
+> - **Native notifications (push).** Promote FCM/push from "Out of scope" to a real track: a Capacitor
+>   push plugin, the Android send path (FCM — but **check RuStore's own push service vs FCM on RuStore
+>   devices**, since Google Play Services may be absent), token registration, and reusing the existing
+>   server notification dispatcher. Owner will bring specifics.
+> - **A test APK for the emulator** (owner asked): the signed APK comes from `android-build` (needs the
+>   promote/tag chain, step 2). A quick **debug** APK is buildable without the release chain if the host
+>   has the Android SDK + JDK 21 (`pnpm build` → `cap sync` → `assembleDebug`).
+> - Possibly other native polish (owner to flag).
 
 - **A. Capacitor scaffolding — ✅ DONE & verified (2026-07-12).** Capacitor 8 native project generated
   under `ui/android/` (tracked), `@capacitor/*` deps + `capacitor.config.ts`, hardware Back in

PLAN.md

@@ -39,10 +39,13 @@ status — without re-deriving decisions.
 | E7 | Admin, reports & catalog | 2 | DONE |
 | E8 | Guest limits | — | DONE |
 | E9 | Tournament fee | future | TODO |
+| E10 | Multi-shop direct rail + ИП fiscalization | 2+ | DONE |
+| E11 | Payment availability kill switch + per-account override | 2 | DONE |
 
 **Release 1** = full mechanics with no real money, exercised via `admin_grant` (E0→E1→E2→E3).
 **Release 2** = money (E4→E5→E6→E7). E8 is standalone (game-behaviour change, can run in
-parallel). E9 is future.
+parallel). E9 is future. E10 splits the `direct` rail into per-channel Robokassa shops + ИП
+fiscalization (post-launch, backend-first).
 
 ---
 
@@ -892,6 +895,123 @@ tournament-entry storage + pricing design.
 
 ---
 
+## E10 — Multi-shop direct rail + ИП fiscalization
+
+**Status:** DONE (merged — the multi-shop PR) · **Release 2+ (post-launch, backend-first)** · depends on: E5 (intake/`Fund`,
+the `robokassa` adapter, the Result callback), E7 (the per-user report — channel breakdown) ·
+mechanics: PAYMENTS §9, §12; decisions D41 (rev), D42–D44.
+
+**Goal.** Split the single Robokassa `direct` rail into **per-channel merchant shops** (web,
+android; ios later) — separate merchant accounts / withdrawal / accounting and a per-channel
+breakdown in the E7 report — while keeping **one `direct` wallet** (D42). Land the wallet/identity
+rules the native apps need (email-only anchor, D43) and revise fiscalization for the owner's move
+to **ИП / 54-ФЗ** (D41 rev). All **additive / contour-safe** and **money-live** → expand-contract
+throughout.
+
+**Locked decisions (owner interview 2026-07-14): D41 (rev), D42, D43, D44.** No wallet-model /
+spend-wall change; the split is merchant-account routing under one `direct` segment. Route the shop
+by the **trusted** `X-Platform` subtype, never a client field; unknown → `web`.
+
+**B1 — Config: one shop → a set of shops.**
+
+- `robokassa.Config` (single) → a **shops registry** keyed by channel (`web`, `android`; `ios`
+  later), each 4 fields (`MerchantLogin`/`Password1`/`Password2`/`IsTest`). New env
+  `BACKEND_ROBOKASSA_WEB_*`, `BACKEND_ROBOKASSA_ANDROID_*`.
+- **Expand-contract, no flag-day:** the legacy `BACKEND_ROBOKASSA_*` seeds the `web` shop; add the
+  new vars; retire the legacy set after the prod rollout sets the split vars. `validate()`: a shop
+  with a login must carry both passwords (mirror the current check), per shop.
+- Config/README + `deploy/.env.example` + the deploy ansible vars.
+
+**B2 — Route the shop by channel (intake).**
+
+- `handleWalletOrder` `SourceDirect` branch: pick the shop by `cxt.Subtype` (`web`/`android`;
+  unknown → `web`). Build the payment request from that shop. The subtype rides the trusted
+  gateway-injected `X-Platform` (`<kind>/<subtype>`, `parsePlatformHeader`) — no spoofable client
+  field. **Verify the gateway emits `direct/android` for the native build**; if it sends a bare
+  `direct/`, add the android subtype (small gateway change).
+- Record the chosen `shop` on the order (feeds B5).
+
+**B3 — Per-shop Result callbacks.**
+
+- The callback must select the right `Password2` → each shop gets its own Result URL:
+  **per-shop public edge routes** (mirror the existing single Robokassa Result route, e.g.
+  `…/result/web`, `…/result/android`), each forwarded to the backend and verified with that shop's
+  config, then the same `Fund` (source stays `direct`). Add the routes to the **Caddyfile
+  `@gateway` matcher** (else they fall to the landing catch-all) **+ a CI probe per route**.
+- Keep the legacy single route alive (shop = `web`) through the expand-contract window until the
+  cabinet Result URLs are cut over.
+
+**B4 — ИП fiscalization (D41 rev) — RESOLVED (owner 2026-07-14): cabinet-side only.** The owner keeps
+Robokassa's cabinet auto-fiscalization (a generic чек is acceptable for the ИП); the optional
+itemized-`Receipt` / `Email` code below is **dropped** — not needed. (Kept for context.)
+
+- **Owner/cabinet:** enable the 54-ФЗ cloud kassa in the Robokassa ЛКК (kassa + ОФД + СНО).
+  Required for ИП regardless of code.
+- **Code (optional, itemized чеки):** send a one-line `Receipt` (pack name, qty 1, `sum`, `tax`
+  per СНО, `payment_object`/`payment_method`) + the customer `Email` (the D36 confirmed anchor) in
+  the payment request; extend the signature to `MerchantLogin:OutSum:InvId:Receipt:Password1`
+  (URL-encode `Receipt`). One line fits the current GET redirect; POST-form only as a URL-length
+  fallback. One feature, all shops. **Sequenced last** — the split (B1–B3, B5, B6) needs no
+  fiscalization. Supersedes the E5 §12 shop-side НПД receipt note.
+
+**B5 — Channel in the report (D44).**
+
+- Additive `shop` column on the order (default `web` / backfill from `origin`); a per-channel
+  breakdown in the E7 per-user report (D40). Expand-contract migration (nullable/defaulted column),
+  **contour-safe** (a schema touch → note the contour `DROP SCHEMA` step in `PRERELEASE.md`).
+
+**B6 — Tests + docs.**
+
+- unit: the `robokassa` shops registry + per-shop `VerifyResult` (right `Password2`);
+  signature-with-`Receipt` (B4); intake shop routing by subtype (web/android/unknown→web).
+- integration: order→per-shop callback→credit (each route), a duplicate credits once, an expired
+  order still honoured; the `shop` recorded + reported.
+- docs: `PAYMENTS.md` (+`_ru`) the multi-shop topology + the ИП/54-ФЗ receipt revision;
+  `deploy/README` + `.env.example` the new vars + the per-shop Result routes + probes;
+  `PRERELEASE.md` the `shop` column contour step.
+
+**Done-criteria.** A `direct/web` order pays through the web shop and `direct/android` through the
+android shop, each verified with its own `Password2`, both crediting one `direct` wallet exactly
+once; the E7 report breaks payments down by channel; the split stays contour-safe (the legacy shop
+still works until the cabinet cutover). B4 (fiscalization) verified when the owner's ИП/ОФД/СНО are
+live.
+
+**Notes/risks.** Edge routes fall through if not in the Caddyfile `@gateway` matcher — add a CI
+probe (field note). The prod rolling deploy skips caddy on config-only changes — force-recreate on a
+Caddyfile change. Money-live: expand-contract only, image rollback DB-safe. Confirm the gateway
+emits `direct/android` for the native build before relying on subtype routing.
+
+---
+
+## E11 — Payment availability kill switch + per-account override
+
+**Status:** DONE · **Release 2** · depends on: E5 (intake/order), E7 (admin console) · mechanics:
+PAYMENTS §9; decisions D45, D46.
+
+**Delivered.** An operator disables purchases live from `/_gm` — a whole rail/channel or one account
+— and the user sees a localized reason on the next purchase attempt. Motivation (owner): real apps
+show broken payments with no explanation; this gives ops a live switch + a clear user message.
+
+- **Rail kill switch** — `payments.rail_status` (per rail `direct:web` / `direct:android` / `vk` /
+  `telegram`): `enabled` + a per-language message, edited on the catalog page. **Fail-open** (no row
+  ⇒ enabled, so payments are never accidentally killed). The intake gate — `CanPurchase` in
+  `handleWalletOrder`, before the order — returns `payment_unavailable` + the localized message;
+  orthogonal to the security gates.
+- **Per-account override** — `payments.account_payment_override` (a row only for non-default; default
+  = no row, cleared by delete): allow / deny / default, edited on the user card. `allow` bypasses
+  **only** the ops rail switch, never the security gates (D46).
+- **Wire** — the message rides an additive `ExecuteResponse.message` (envelope layer,
+  frozen-contract-safe; the gateway forwards a backend domain-error message via `DomainMessage`); the
+  client reads it into `GatewayError.message` and shows it on a `payment_unavailable` buy attempt.
+- **Tests** — the pure gate `PurchaseGate` (unit, TDD); the store + gate + override end-to-end
+  (integration, migration `00016`); the client (svelte-check / vitest). **Docs** — PAYMENTS (+`_ru`),
+  decisions D45 / D46.
+
+**Contour-safe:** additive migration (two new tables, no wipe); the wire add is additive; fail-open,
+so nothing is disabled until an operator acts.
+
+---
+
 ## Verification & CI (all stages)
 
 - Per-stage tests at the layers above; **compliance-gate regression is mandatory** (a

assets/icons/brand/build-android-res.mjs

@@ -19,6 +19,11 @@ const uri = p => 'data:image/png;base64,' + readFileSync(p).toString('base64');
 const BG = uri(join(ROOT, 'ui', 'assets', 'icon-background.png'));
 const FG = uri(join(ROOT, 'ui', 'assets', 'icon-foreground.png'));
 const MONO = uri(join(DIR, 'android-monochrome.png'));
+// The full-bleed master (square tile + master mark) — the legacy SQUARE launcher (API < 26)
+// uses it so old Android shows a large mark rather than the safe-zone foreground shrunk into
+// the middle. The round legacy icon keeps the safe-zone composite (a round mask would clip
+// the master's corner ✻).
+const MASTER = uri(join(ROOT, 'ui', 'assets', 'icon.png'));
 
 // density: [adaptive-layer px (108 dp), legacy launcher px (48 dp)]
 const D = { ldpi: [81, 36], mdpi: [108, 48], hdpi: [162, 72], xhdpi: [216, 96], xxhdpi: [324, 144], xxxhdpi: [432, 192] };
@@ -38,8 +43,9 @@ for (const [d, [fg, lg]] of Object.entries(D)) {
   writeFileSync(join(dir, 'ic_launcher_background.png'), await shot(im(BG, fg), fg, false));
   writeFileSync(join(dir, 'ic_launcher_foreground.png'), await shot(im(FG, fg), fg, true));
   writeFileSync(join(dir, 'ic_launcher_monochrome.png'), await shot(im(MONO, fg), fg, true));
-  const comp = `<div style="position:relative;width:${lg}px;height:${lg}px">${im(BG, lg)}<div style="position:absolute;inset:0">${im(FG, lg)}</div></div>`;
+  // Square launcher: the full-bleed master (large mark). Round launcher: the safe-zone
-  writeFileSync(join(dir, 'ic_launcher.png'), await shot(comp, lg, false));
+  // composite, circle-clipped (the master's corner ✻ would be clipped by the round mask).
+  writeFileSync(join(dir, 'ic_launcher.png'), await shot(im(MASTER, lg), lg, false));
   const round = `<div style="width:${lg}px;height:${lg}px;border-radius:50%;overflow:hidden;position:relative">${im(BG, lg)}<div style="position:absolute;inset:0">${im(FG, lg)}</div></div>`;
   writeFileSync(join(dir, 'ic_launcher_round.png'), await shot(round, lg, true));
   console.log('mipmap-' + d, 'ok');

assets/icons/brand/build-icon.mjs

@@ -33,8 +33,12 @@ const SHADE = 0.15;                   // black, this alpha bottom-left -> transp
 // The mark, placed for the standalone master (bottom-right biased, full-bleed):
 const MASTER = { lh: 0.6055, lc: [0.4814, 0.4922], sd: 0.1729, sc: [0.7881, 0.7881] };
 // The mark, placed for the Android foreground layer (centred-ish inside the 61% safe
-// zone, nudged right 8% / down 3% for optical balance under the round mask; smaller ✻):
+// zone, nudged right 8% / down 3% for optical balance under the round mask; smaller ✻).
-const FOREGROUND = { lh: 0.5391, lc: [0.5234, 0.4951], sd: 0.1318, sc: [0.7627, 0.7266] };
+// Every value is the earlier placement scaled 0.75 about the icon centre (0.5, 0.5): the
+// whole mark is 25% smaller, its «Э»↔✻ arrangement unchanged, so the ✻ that used to graze
+// the round mask now sits well inside the safe zone. Round-mask launchers (adaptive + the
+// legacy round icon) get more breathing room; the full-bleed master is untouched.
+const FOREGROUND = { lh: 0.4043, lc: [0.5176, 0.4963], sd: 0.0989, sc: [0.6970, 0.6700] };
 
 const PALETTE = {
   light: { wood: '#e6b053', ink: '#5a3a12', grain: '#d8a54e' },

backend/Dockerfile

@@ -49,9 +49,14 @@ COPY --from=build /out/backend /usr/local/bin/backend
 # Own the seed dictionary as the nonroot runtime user (UID 65532): a named volume
 # mounted at /opt/dawg inherits this ownership on first use, so the admin console
 # can write new version subdirectories at runtime. The volume preserves uploaded
-# versions across deploys and, once seeded, is not re-seeded — so after bootstrap
+# versions across deploys and, once seeded, is not re-seeded (ARCHITECTURE.md §5).
-# every dictionary change goes through the console, not a rebuild (ARCHITECTURE.md §5).
 COPY --from=dawg --chown=65532:65532 /dawg /opt/dawg
+# A second, UNSHADOWED copy of the build's DAWGs: the /opt/dawg volume mount hides the
+# image's copy there, so this is where engine.DeliverVersion reads the build version from
+# to add it (add-only) to the volume on boot — the deploy-delivers path that lets a bumped
+# BACKEND_DICT_VERSION go live for new games without an admin upload (ARCHITECTURE.md §5).
+COPY --from=dawg --chown=65532:65532 /dawg /opt/dawg-seed
 ENV BACKEND_DICT_DIR=/opt/dawg
+ENV BACKEND_DICT_SEED_DIR=/opt/dawg-seed
 ENV BACKEND_DICT_VERSION=${DICT_VERSION}
 ENTRYPOINT ["/usr/local/bin/backend"]

backend/cmd/backend/main.go

@@ -111,6 +111,12 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	}
 	logger.Info("database migrations applied")
 
+	// Deliver the build's dictionary version onto the persistent volume if a redeploy
+	// bumped it (add-only; old versions in-flight games pin are untouched), so the new
+	// dictionary is resident and can be activated below without an admin upload.
+	if err := engine.DeliverVersion(cfg.Game.DictDir, cfg.Game.DictSeedDir, cfg.Game.DictVersion); err != nil {
+		return fmt.Errorf("deliver dictionary version: %w", err)
+	}
 	registry, err := engine.OpenWithVersions(cfg.Game.DictDir, cfg.Game.DictVersion)
 	if err != nil {
 		return fmt.Errorf("load dictionaries: %w", err)
@@ -118,6 +124,7 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	defer func() { _ = registry.Close() }()
 	logger.Info("dictionaries loaded",
 		zap.String("dir", cfg.Game.DictDir),
+		zap.String("seed_dir", cfg.Game.DictSeedDir),
 		zap.String("version", cfg.Game.DictVersion))
 
 	// Admin console: an optional backend client to the Telegram connector
@@ -147,10 +154,10 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	accounts := account.NewStore(db)
 	accounts.SetMetrics(tel.MeterProvider().Meter("scrabble/backend/account"))
 	games := game.NewService(game.NewStore(db), accounts, registry, cfg.Game, logger)
-	// Reconcile the persisted active dictionary version with the registry: a
+	// Reconcile the active dictionary version with the registry: the build version
-	// version activated through the admin console (and written to the dictionary
+	// (delivered above) becomes active so a redeploy that bumped it goes live for new
-	// volume) is adopted again after a restart; otherwise the configured seed
+	// games, except a newer version installed out-of-band through the admin console,
-	// version is kept and persisted (docs/ARCHITECTURE.md §5).
+	// which is not downgraded by a restart (docs/ARCHITECTURE.md §5).
 	if err := games.InitActiveVersion(ctx); err != nil {
 		return fmt.Errorf("init active dictionary version: %w", err)
 	}

backend/internal/account/account.go

@@ -10,6 +10,7 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"math/rand/v2"
 	"strings"
 	"time"
 
@@ -525,8 +526,13 @@ func (s *Store) create(ctx context.Context, kind, externalID string, seed provis
 	return created, nil
 }
 
-// guestDisplayName is the display name stamped on a freshly provisioned guest.
+// guestDisplayName mints the display name stamped on a freshly provisioned guest: "Guest" plus a
-const guestDisplayName = "Guest"
+// random six-digit suffix (e.g. "Guest042317"), so a guest is distinguishable to opponents — in a
+// random match the other player sees a distinct name rather than every guest reading a bare
+// "Guest". Not an identifier and not unique (collisions are harmless — it is a label only).
+func guestDisplayName() string {
+	return fmt.Sprintf("Guest%06d", rand.IntN(1_000_000))
+}
 
 // ProvisionGuest creates a fresh ephemeral guest account: a durable row carrying
 // no identity, flagged is_guest, so it can hold a session and a game seat (both
@@ -534,7 +540,7 @@ const guestDisplayName = "Guest"
 // and history. Guests are not reused — each bootstrap mints a new account. browserTZ
 // (the client's detected "±HH:MM" UTC offset) seeds the guest's time zone, falling
 // back to the 'UTC' default when empty or malformed.
-func (s *Store) ProvisionGuest(ctx context.Context, browserTZ string) (Account, error) {
+func (s *Store) ProvisionGuest(ctx context.Context, browserTZ, language string) (Account, error) {
 	accountID, err := uuid.NewV7()
 	if err != nil {
 		return Account{}, fmt.Errorf("account: new guest id: %w", err)
@@ -543,9 +549,17 @@ func (s *Store) ProvisionGuest(ctx context.Context, browserTZ string) (Account,
 	if tz == "" {
 		tz = "UTC"
 	}
+	// Seed the interface language from the client's detected locale (validated to a supported
+	// one), so a fresh guest's language-dependent server content — the ad banner, bot messages —
+	// is right from first contact rather than the 'en' column default until the client's later
+	// language reconcile catches up. An unsupported or absent code keeps the 'en' default.
+	lang := supportedLanguage(language)
+	if lang == "" {
+		lang = "en"
+	}
 	stmt := table.Accounts.
-		INSERT(table.Accounts.AccountID, table.Accounts.DisplayName, table.Accounts.IsGuest, table.Accounts.TimeZone).
+		INSERT(table.Accounts.AccountID, table.Accounts.DisplayName, table.Accounts.IsGuest, table.Accounts.TimeZone, table.Accounts.PreferredLanguage).
-		VALUES(accountID, guestDisplayName, true, tz).
+		VALUES(accountID, guestDisplayName(), true, tz, lang).
 		RETURNING(table.Accounts.AllColumns)
 
 	var row model.Accounts

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

@@ -30,6 +30,18 @@
 <div><button type="submit">Save</button></div>
 </form>
 </section>
+<section class="panel"><h2>Payment availability (kill switch)</h2>
+<p class="note">Turn purchases off on a rail/channel and show the user a localized reason on their next attempt. Unchecked = off; an empty message shows a built-in &ldquo;temporarily unavailable&rdquo;. Fail-open: a rail you never touch stays on. A per-user &ldquo;allow&rdquo; override (on a user card) bypasses this switch.</p>
+{{range .Rails}}
+<form class="form col" method="post" action="/_gm/catalog/rail-status">
+<input type="hidden" name="rail" value="{{.Rail}}">
+<label><input type="checkbox" name="enabled" {{if .Enabled}}checked{{end}}> <code>{{.Rail}}</code> &mdash; purchases enabled</label>
+<label>Message RU <input type="text" name="message_ru" maxlength="200" value="{{.MessageRU}}"></label>
+<label>Message EN <input type="text" name="message_en" maxlength="200" value="{{.MessageEN}}"></label>
+<div><button type="submit">Save</button></div>
+</form>
+{{end}}
+</section>
 <section class="panel"><h2>Products</h2>
 <p class="note">Showing {{if .ShowAll}}<strong>all</strong> products (active + archived) — <a href="/_gm/catalog">active only</a>{{else}}<strong>active</strong> products — <a href="/_gm/catalog?all=1">show all (incl. archived)</a>{{end}}.</p>
 <table class="list">

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

@@ -72,14 +72,24 @@
 {{if or .Finance.Abuse .Finance.Loss}}<li><b>Refund risk</b> <span class="warn">{{if .Finance.Abuse}}abuse-flagged{{end}}{{if .Finance.Loss}} · loss {{.Finance.Loss}} chips{{end}}</span></li>{{end}}
 </ul>
 {{else}}<p class="note">no balances or benefits</p>{{end}}
+<h3>Payment override</h3>
+<form class="form" method="post" action="/_gm/users/{{.ID}}/purchase-override">
+<label>Purchases for this account
+<select name="override">
+<option value="default" {{if eq .PurchaseOverride "default"}}selected{{end}}>Default (follow the rail switch)</option>
+<option value="allow" {{if eq .PurchaseOverride "allow"}}selected{{end}}>Always allow (bypasses the rail switch only, not security)</option>
+<option value="deny" {{if eq .PurchaseOverride "deny"}}selected{{end}}>Always deny</option>
+</select></label>
+<div><button type="submit">Save</button></div>
+</form>
 <h3>Ledger</h3>
 {{$uid := .ID}}
 {{if .Finance.Ledger}}
 <table class="list">
-<thead><tr><th>Time</th><th>Kind</th><th>Source</th><th>Origin</th><th>Chips</th><th>Order</th><th>Provider</th><th>Detail</th><th></th></tr></thead>
+<thead><tr><th>Time</th><th>Kind</th><th>Source</th><th>Origin</th><th>Chips</th><th>Order</th><th>Provider</th><th>Shop</th><th>Detail</th><th></th></tr></thead>
 <tbody>
 {{range .Finance.Ledger}}
-<tr><td>{{.At}}</td><td>{{.Kind}}</td><td>{{.Source}}</td><td>{{.Origin}}</td><td>{{.ChipsDelta}}</td><td>{{if .Order}}<code>{{.Order}}</code>{{end}}</td><td>{{.Provider}}</td><td>{{if .Snapshot}}<code>{{.Snapshot}}</code>{{end}}</td>
+<tr><td>{{.At}}</td><td>{{.Kind}}</td><td>{{.Source}}</td><td>{{.Origin}}</td><td>{{.ChipsDelta}}</td><td>{{if .Order}}<code>{{.Order}}</code>{{end}}</td><td>{{.Provider}}</td><td>{{.Shop}}</td><td>{{if .Snapshot}}<code>{{.Snapshot}}</code>{{end}}</td>
 <td>{{if and (eq .Kind "fund") .Order}}<form class="form" method="post" action="/_gm/users/{{$uid}}/refund" onsubmit="return confirm('Refund this order in full? Record the money refund on the rail first; this revokes the chips (floored at 0).')"><input type="hidden" name="order_id" value="{{.Order}}"><button type="submit">Refund</button></form>{{end}}</td></tr>
 {{end}}
 </tbody>

backend/internal/adminconsole/views.go

@@ -198,6 +198,9 @@ type UserDetailView struct {
 	// Finance is the account's payments picture (balances, benefits, refund risk, ledger). Present
 	// is false when the payments domain is unwired.
 	Finance FinanceView
+	// PurchaseOverride is the account's per-account purchase override ("default"/"allow"/"deny"),
+	// shown in and edited from the user card's payment-override control.
+	PurchaseOverride string
 	// Grant is the admin-grant panel (origin picker + grantable products). Present is false when the
 	// payments domain is unwired.
 	Grant GrantFormView
@@ -232,8 +235,8 @@ type BenefitRow struct {
 }
 
 // LedgerRow is one append-only ledger entry: its kind, funding source / benefit origin, signed chip
-// delta, the product / order / provider it references (empty when none), the raw snapshot JSON and
+// delta, the product / order / provider / direct-rail shop it references (empty when none), the raw
-// the pre-formatted time.
+// snapshot JSON and the pre-formatted time.
 type LedgerRow struct {
 	Kind       string
 	Source     string
@@ -242,6 +245,7 @@ type LedgerRow struct {
 	Product    string
 	Order      string
 	Provider   string
+	Shop       string
 	Snapshot   string
 	At         string
 }
@@ -686,6 +690,18 @@ type CatalogView struct {
 	RewardPayout    int
 	RewardDailyCap  int
 	RewardHourlyCap int
+	// Rails is the per-rail operational kill-switch state (enabled + per-language off-message), shown
+	// in and edited from the page's payment-availability form.
+	Rails []RailStatusRow
+}
+
+// RailStatusRow is one payment rail's operational availability in the kill-switch editor: the rail
+// key, whether purchases are enabled, and the operator's per-language off-message shown to the user.
+type RailStatusRow struct {
+	Rail      string
+	Enabled   bool
+	MessageRU string
+	MessageEN string
 }
 
 // ProductRow is one product in the catalog list: its composition, prices, the archived flag

backend/internal/config/config.go

@@ -65,9 +65,9 @@ type Config struct {
 	// RendererURL is the base URL of the internal image-render sidecar (e.g.
 	// http://renderer:8090). Empty disables the PNG export artifact.
 	RendererURL string
-	// Robokassa configures the direct-rail (RUB) payment provider. An empty MerchantLogin
+	// Robokassa configures the direct-rail (RUB) payment provider — one merchant shop per channel
-	// leaves the direct order and Result-callback endpoints unregistered.
+	// (D42). An empty set leaves the direct order and Result-callback endpoints unregistered.
-	Robokassa robokassa.Config
+	Robokassa robokassa.Shops
 }
 
 // Defaults applied when the corresponding environment variable is unset.
@@ -106,6 +106,7 @@ func Load() (Config, error) {
 	gm := game.DefaultConfig()
 	gm.DictDir = envOr("BACKEND_DICT_DIR", gm.DictDir)
 	gm.DictVersion = envOr("BACKEND_DICT_VERSION", gm.DictVersion)
+	gm.DictSeedDir = envOr("BACKEND_DICT_SEED_DIR", gm.DictSeedDir)
 	if gm.TimeoutSweepInterval, err = envDuration("BACKEND_GAME_TIMEOUT_SWEEP_INTERVAL", gm.TimeoutSweepInterval); err != nil {
 		return Config{}, err
 	}
@@ -157,11 +158,19 @@ func Load() (Config, error) {
 		AdminTo:   os.Getenv("BACKEND_ADMIN_EMAIL"),
 	}
 
-	robo := robokassa.Config{
+	// Robokassa direct rail: one merchant shop per channel (D42). The legacy single-shop vars seed
-		MerchantLogin: os.Getenv("BACKEND_ROBOKASSA_MERCHANT_LOGIN"),
+	// the web channel so existing deploys keep working; the per-channel vars add the rest. A shop
-		Password1:     os.Getenv("BACKEND_ROBOKASSA_PASSWORD1"),
+	// with no MerchantLogin is dropped (the rail stays dormant when none is configured).
-		Password2:     os.Getenv("BACKEND_ROBOKASSA_PASSWORD2"),
+	shops := robokassa.Shops{}
-		IsTest:        os.Getenv("BACKEND_ROBOKASSA_TEST") == "1",
+	web := robokassaShop("BACKEND_ROBOKASSA_WEB")
+	if web.MerchantLogin == "" {
+		web = robokassaShop("BACKEND_ROBOKASSA") // legacy single-shop credentials seed the web channel
+	}
+	if web.MerchantLogin != "" {
+		shops[robokassa.ChannelWeb] = web
+	}
+	if android := robokassaShop("BACKEND_ROBOKASSA_ANDROID"); android.MerchantLogin != "" {
+		shops[robokassa.ChannelAndroid] = android
 	}
 
 	c := Config{
@@ -181,7 +190,7 @@ func Load() (Config, error) {
 		GuestRetention:    guestRetention,
 		ExportSignKey:     os.Getenv("BACKEND_EXPORT_SIGN_KEY"),
 		RendererURL:       os.Getenv("BACKEND_RENDERER_URL"),
-		Robokassa:         robo,
+		Robokassa:         shops,
 	}
 	if err := c.validate(); err != nil {
 		return Config{}, err
@@ -234,8 +243,10 @@ func (c Config) validate() error {
 			return fmt.Errorf("config: BACKEND_PUBLIC_BASE_URL %q must be an absolute URL (scheme://host)", c.PublicBaseURL)
 		}
 	}
-	if c.Robokassa.MerchantLogin != "" && (c.Robokassa.Password1 == "" || c.Robokassa.Password2 == "") {
+	for channel, shop := range c.Robokassa {
-		return fmt.Errorf("config: BACKEND_ROBOKASSA_PASSWORD1 and BACKEND_ROBOKASSA_PASSWORD2 must be set when BACKEND_ROBOKASSA_MERCHANT_LOGIN is")
+		if shop.Password1 == "" || shop.Password2 == "" {
+			return fmt.Errorf("config: robokassa shop %q: password1 and password2 must be set when its merchant login is", channel)
+		}
 	}
 	return nil
 }
@@ -276,3 +287,15 @@ func envDuration(key string, fallback time.Duration) (time.Duration, error) {
 	}
 	return d, nil
 }
+
+// robokassaShop reads a Robokassa shop's four credentials from the environment under prefix (e.g.
+// "BACKEND_ROBOKASSA_WEB" → _MERCHANT_LOGIN / _PASSWORD1 / _PASSWORD2 / _TEST). A missing
+// MerchantLogin yields a zero Config the caller drops.
+func robokassaShop(prefix string) robokassa.Config {
+	return robokassa.Config{
+		MerchantLogin: os.Getenv(prefix + "_MERCHANT_LOGIN"),
+		Password1:     os.Getenv(prefix + "_PASSWORD1"),
+		Password2:     os.Getenv(prefix + "_PASSWORD2"),
+		IsTest:        os.Getenv(prefix+"_TEST") == "1",
+	}
+}

backend/internal/engine/deliver.go

@@ -0,0 +1,92 @@
+package engine
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// DeliverVersion makes the build's dictionary version resident on the persistent
+// dictionary volume without disturbing the versions in-flight games already pin.
+//
+// The volume is seeded from the image once and never re-seeded, and the image's
+// /opt/dawg is shadowed by that volume mount, so a redeploy that bumped
+// BACKEND_DICT_VERSION cannot otherwise make the new DAWGs reachable at runtime.
+// The image therefore keeps an unshadowed read-only copy at seedDir, and this
+// copies it into dictDir/<version>/ when the version is not already present —
+// neither the flat seed's own recorded label nor an existing version
+// subdirectory. It is add-only and idempotent: the flat seed and any prior admin
+// uploads are never touched, so old games keep the version they pin while the new
+// one becomes resident and activatable (see game.Service.InitActiveVersion). A
+// blank seedDir disables delivery (the pre-existing seed-only behaviour).
+func DeliverVersion(dictDir, seedDir, version string) error {
+	if seedDir == "" || version == "" {
+		return nil
+	}
+	target := filepath.Join(dictDir, version)
+	if _, err := os.Stat(target); err == nil {
+		return nil // already delivered on a prior boot
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("engine: stat delivered dictionary %s: %w", target, err)
+	}
+	// A fresh volume is populated from the image and recorded as this version by the
+	// marker: it is the flat dir, so there is nothing to deliver. resolveSeedVersion
+	// records the label on first use, matching OpenWithVersions.
+	seed, err := resolveSeedVersion(dictDir, version)
+	if err != nil {
+		return err
+	}
+	if seed == version {
+		return nil
+	}
+	// Stage into a dot-prefixed directory (skipped by OpenWithVersions' version scan)
+	// then rename, so a crash mid-copy never leaves a half-populated version subdir.
+	staging := filepath.Join(dictDir, ".staging-deliver-"+version)
+	if err := os.RemoveAll(staging); err != nil {
+		return fmt.Errorf("engine: clear deliver staging %s: %w", staging, err)
+	}
+	if err := os.MkdirAll(staging, 0o755); err != nil {
+		return fmt.Errorf("engine: create deliver staging %s: %w", staging, err)
+	}
+	for _, file := range dictFiles {
+		src := filepath.Join(seedDir, file)
+		if _, err := os.Stat(src); errors.Is(err, os.ErrNotExist) {
+			continue // a variant absent from the seed is simply absent under this version
+		} else if err != nil {
+			_ = os.RemoveAll(staging)
+			return fmt.Errorf("engine: stat seed dawg %s: %w", src, err)
+		}
+		if err := copyFile(src, filepath.Join(staging, file)); err != nil {
+			_ = os.RemoveAll(staging)
+			return err
+		}
+	}
+	if err := os.Rename(staging, target); err != nil {
+		_ = os.RemoveAll(staging)
+		return fmt.Errorf("engine: publish delivered dictionary %s: %w", target, err)
+	}
+	return nil
+}
+
+// copyFile copies a single file, truncating the destination.
+func copyFile(src, dst string) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("engine: open %s: %w", src, err)
+	}
+	defer func() { _ = in.Close() }()
+	out, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
+	if err != nil {
+		return fmt.Errorf("engine: create %s: %w", dst, err)
+	}
+	if _, err := io.Copy(out, in); err != nil {
+		_ = out.Close()
+		return fmt.Errorf("engine: copy %s -> %s: %w", src, dst, err)
+	}
+	if err := out.Close(); err != nil {
+		return fmt.Errorf("engine: finalise %s: %w", dst, err)
+	}
+	return nil
+}

backend/internal/engine/deliver_test.go

@@ -0,0 +1,68 @@
+package engine
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestDeliverVersion(t *testing.T) {
+	// A blank seed directory disables delivery (the pre-existing seed-only behaviour).
+	if err := DeliverVersion(t.TempDir(), "", "v1.3.1"); err != nil {
+		t.Fatalf("blank seedDir: %v", err)
+	}
+
+	// An existing volume flat-seeded as v1.3.0 gets v1.3.1 delivered as a subdirectory,
+	// add-only: the flat seed's marker is left intact and the new version's DAWGs land.
+	dict := t.TempDir()
+	seed := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dict, seedMarkerFile), []byte("v1.3.0\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range dictFiles {
+		if err := os.WriteFile(filepath.Join(seed, f), []byte("dawg:"+f), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := DeliverVersion(dict, seed, "v1.3.1"); err != nil {
+		t.Fatalf("deliver v1.3.1: %v", err)
+	}
+	for _, f := range dictFiles {
+		got, err := os.ReadFile(filepath.Join(dict, "v1.3.1", f))
+		if err != nil {
+			t.Fatalf("delivered %s: %v", f, err)
+		}
+		if string(got) != "dawg:"+f {
+			t.Errorf("delivered %s = %q, want the seed bytes", f, got)
+		}
+	}
+	if m, _ := os.ReadFile(filepath.Join(dict, seedMarkerFile)); string(m) != "v1.3.0\n" {
+		t.Errorf("flat seed marker relabelled to %q (delivery must be add-only)", m)
+	}
+	// Idempotent: a second call is a no-op and leaves no staging directory behind.
+	if err := DeliverVersion(dict, seed, "v1.3.1"); err != nil {
+		t.Fatalf("re-deliver v1.3.1: %v", err)
+	}
+	if entries, _ := os.ReadDir(dict); hasStaging(entries) {
+		t.Errorf("a staging directory survived delivery")
+	}
+
+	// On a fresh directory the build version becomes the flat seed, so nothing is delivered
+	// as a redundant subdirectory.
+	fresh := t.TempDir()
+	if err := DeliverVersion(fresh, seed, "v1.3.1"); err != nil {
+		t.Fatalf("fresh deliver: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(fresh, "v1.3.1")); !os.IsNotExist(err) {
+		t.Errorf("fresh volume got a redundant v1.3.1 subdir; it should be the flat seed")
+	}
+}
+
+func hasStaging(entries []os.DirEntry) bool {
+	for _, e := range entries {
+		if len(e.Name()) >= len(".staging") && e.Name()[:len(".staging")] == ".staging" {
+			return true
+		}
+	}
+	return false
+}

backend/internal/engine/seedmarker.go

@@ -25,11 +25,11 @@ const seedMarkerFile = ".seed_version"
 //     BACKEND_DICT_VERSION) and return it — the seed of a fresh volume;
 //   - already-seeded directory: return the recorded marker and ignore bootVersion.
 //
-// So bumping the build seed on a live volume is a harmless no-op (it only takes
+// So a later build seed never relabels the already-seeded flat bytes — which would void
-// effect on a future fresh volume) instead of relabelling the already-seeded bytes —
+// games pinned to the prior label and mis-serve new ones. The new build version is instead
-// which would void games pinned to the prior label and mis-serve new ones. New games
+// delivered as a NEW subdirectory (DeliverVersion) and made active (Service.InitActiveVersion),
-// still pin the active version (DB-persisted, set by the admin console), which is the
+// so a redeploy still moves new games to it while old games keep the flat label. New games
-// real way a running contour moves to a new release.
+// pin the active version (DB-persisted); a console upload can also set it out-of-band.
 //
 // A directory that cannot be written makes the first record fail; that also breaks
 // the admin console (which writes version subdirectories here), so the error is

backend/internal/game/config.go

@@ -18,6 +18,13 @@ type Config struct {
 	// DictVersion labels the dictionary version new games pin. Sourced from
 	// BACKEND_DICT_VERSION.
 	DictVersion string
+	// DictSeedDir holds the image's read-only copy of the build's DictVersion DAWGs,
+	// on a path the persistent DictDir volume does NOT shadow. On boot the backend
+	// delivers this version into DictDir/<DictVersion>/ if absent (add-only), so a
+	// redeploy that bumped DICT_VERSION makes the new dictionary resident and activatable
+	// without disturbing the versions in-flight games already pin. Sourced from
+	// BACKEND_DICT_SEED_DIR; empty disables delivery (the pre-existing seed-only behaviour).
+	DictSeedDir string
 	// TimeoutSweepInterval is how often the sweeper scans for overdue turns.
 	// Sourced from BACKEND_GAME_TIMEOUT_SWEEP_INTERVAL.
 	TimeoutSweepInterval time.Duration

backend/internal/game/service.go

@@ -232,21 +232,31 @@ func (svc *Service) ActiveVersion() string {
 }
 
 // InitActiveVersion reconciles the persisted active dictionary version with the
-// registry at startup. If a version was persisted and is resident, it becomes the
+// registry at startup and makes the build's version (BACKEND_DICT_VERSION, delivered
-// active version; otherwise the configured seed version is kept and persisted as
+// resident by engine.DeliverVersion) authoritative: a redeploy that bumped the build
-// the initial active version. Call once during wiring, before serving traffic.
+// version thus activates it for new games without any admin step, while old games keep
+// the version they pin. The one exception is a version installed out-of-band through
+// the admin console that is NEWER than the build version and still resident — it is
+// kept, so a restart on an older image never downgrades a hotfix. A build version that
+// is not resident (delivery disabled or a partial state) falls back to a resident
+// persisted version. The chosen version is persisted so the admin console reflects it.
+// Call once during wiring, before serving traffic.
 func (svc *Service) InitActiveVersion(ctx context.Context) error {
 	persisted, ok, err := svc.store.GetActiveDictVersion(ctx)
 	if err != nil {
 		return err
 	}
-	if ok && svc.versionResident(persisted) {
+	target := svc.activeVersion() // the build seed version (config.DictVersion)
-		svc.verMu.Lock()
+	if ok && svc.versionResident(persisted) && compareDictVersions(persisted, target) > 0 {
-		svc.version = persisted
+		target = persisted // a newer out-of-band install wins over the build version
-		svc.verMu.Unlock()
-		return nil
 	}
-	return svc.store.SetActiveDictVersion(ctx, svc.activeVersion())
+	if !svc.versionResident(target) && ok && svc.versionResident(persisted) {
+		target = persisted // the build version is unloadable — keep a resident one
+	}
+	svc.verMu.Lock()
+	svc.version = target
+	svc.verMu.Unlock()
+	return svc.store.SetActiveDictVersion(ctx, target)
 }
 
 // SetActiveVersion records version as the active dictionary version, persisting it

backend/internal/game/version.go

@@ -0,0 +1,45 @@
+package game
+
+import (
+	"strconv"
+	"strings"
+)
+
+// compareDictVersions orders two dictionary version labels of the shape "vMAJOR.MINOR.PATCH"
+// numerically, returning -1, 0 or +1 as a is less than, equal to or greater than b. Labels
+// that do not parse fall back to a byte comparison, so the ordering is always total (a mixed
+// or malformed pair never crashes the boot-time active-version reconcile).
+func compareDictVersions(a, b string) int {
+	pa, oka := parseDictVersion(a)
+	pb, okb := parseDictVersion(b)
+	if !oka || !okb {
+		return strings.Compare(a, b)
+	}
+	for i := range pa {
+		if pa[i] != pb[i] {
+			if pa[i] < pb[i] {
+				return -1
+			}
+			return 1
+		}
+	}
+	return 0
+}
+
+// parseDictVersion parses a "vMAJOR.MINOR.PATCH" label into its three numeric parts, reporting
+// whether it matched that shape.
+func parseDictVersion(v string) ([3]int, bool) {
+	parts := strings.Split(strings.TrimPrefix(v, "v"), ".")
+	if len(parts) != 3 {
+		return [3]int{}, false
+	}
+	var out [3]int
+	for i, p := range parts {
+		n, err := strconv.Atoi(p)
+		if err != nil {
+			return [3]int{}, false
+		}
+		out[i] = n
+	}
+	return out, true
+}

backend/internal/game/version_test.go

@@ -0,0 +1,37 @@
+package game
+
+import "testing"
+
+func TestCompareDictVersions(t *testing.T) {
+	cases := []struct {
+		a, b string
+		want int
+	}{
+		{"v1.3.0", "v1.3.1", -1},
+		{"v1.3.1", "v1.3.0", 1},
+		{"v1.3.1", "v1.3.1", 0},
+		{"v1.3.9", "v1.3.10", -1}, // numeric, not lexical
+		{"v1.10.0", "v1.9.0", 1},
+		{"v2.0.0", "v1.9.9", 1},
+		{"1.3.1", "v1.3.1", 0}, // the leading v is optional
+		// Non-semver falls back to a byte comparison, keeping the ordering total.
+		{"weird", "weird", 0},
+		{"a", "b", -1},
+	}
+	for _, c := range cases {
+		if got := compareDictVersions(c.a, c.b); sign(got) != c.want {
+			t.Errorf("compareDictVersions(%q, %q) = %d, want sign %d", c.a, c.b, got, c.want)
+		}
+	}
+}
+
+func sign(n int) int {
+	switch {
+	case n < 0:
+		return -1
+	case n > 0:
+		return 1
+	default:
+		return 0
+	}
+}

backend/internal/inttest/account_test.go

@@ -5,6 +5,7 @@ package inttest
 import (
 	"context"
 	"errors"
+	"regexp"
 	"testing"
 	"time"
 
@@ -229,21 +230,40 @@ func TestProvisionSeedsTimeZone(t *testing.T) {
 		t.Errorf("TimeZone = %q, want UTC fallback for a malformed offset", bad.TimeZone)
 	}
 
-	// A guest is seeded its detected offset; an empty one keeps the UTC default.
+	// A guest is seeded its detected offset and interface language; an empty offset keeps the
-	guest, err := store.ProvisionGuest(ctx, "-05:30")
+	// UTC default and an empty/unsupported language keeps the 'en' default.
+	guest, err := store.ProvisionGuest(ctx, "-05:30", "ru")
 	if err != nil {
 		t.Fatalf("provision guest: %v", err)
 	}
 	if guest.TimeZone != "-05:30" {
 		t.Errorf("guest TimeZone = %q, want the seeded -05:30", guest.TimeZone)
 	}
-	plainGuest, err := store.ProvisionGuest(ctx, "")
+	if guest.PreferredLanguage != "ru" {
+		t.Errorf("guest PreferredLanguage = %q, want the seeded ru", guest.PreferredLanguage)
+	}
+	// A guest's display name is "Guest" + a random six-digit suffix (distinct to opponents).
+	if m, _ := regexp.MatchString(`^Guest\d{6}$`, guest.DisplayName); !m {
+		t.Errorf("guest DisplayName = %q, want Guest + 6 digits", guest.DisplayName)
+	}
+	plainGuest, err := store.ProvisionGuest(ctx, "", "")
 	if err != nil {
 		t.Fatalf("provision plain guest: %v", err)
 	}
 	if plainGuest.TimeZone != "UTC" {
 		t.Errorf("plain guest TimeZone = %q, want UTC default", plainGuest.TimeZone)
 	}
+	if plainGuest.PreferredLanguage != "en" {
+		t.Errorf("plain guest PreferredLanguage = %q, want en default", plainGuest.PreferredLanguage)
+	}
+	// An unsupported locale falls back to the 'en' default rather than persisting a junk value.
+	frGuest, err := store.ProvisionGuest(ctx, "", "fr-FR")
+	if err != nil {
+		t.Fatalf("provision fr guest: %v", err)
+	}
+	if frGuest.PreferredLanguage != "en" {
+		t.Errorf("unsupported-locale guest PreferredLanguage = %q, want en default", frGuest.PreferredLanguage)
+	}
 }
 
 // TestProvisionTelegramUnknownLanguageDefaults checks an unsupported Telegram

backend/internal/inttest/delete_test.go

@@ -216,7 +216,7 @@ func TestConfirmCodeClearsGuest(t *testing.T) {
 	mailer := &capturingMailer{}
 	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
 
-	guest, err := store.ProvisionGuest(ctx, "")
+	guest, err := store.ProvisionGuest(ctx, "", "")
 	if err != nil {
 		t.Fatalf("provision guest: %v", err)
 	}

backend/internal/inttest/dictionary_update_test.go

@@ -103,14 +103,31 @@ func TestDictionaryUpdateFlow(t *testing.T) {
 		t.Errorf("installed dawg missing on disk: %v", err)
 	}
 
-	// The choice survives a restart: a fresh service over the same DB and registry
+	// The choice survives a restart on the SAME build: an out-of-band admin install newer
-	// re-adopts the persisted active version.
+	// than the build version is not downgraded (a restart on an older image keeps the hotfix).
 	restarted := newGameServiceOn(dir, "v1.0.0", reg)
 	if err := restarted.InitActiveVersion(ctx); err != nil {
 		t.Fatalf("restart init: %v", err)
 	}
 	if got := restarted.ActiveVersion(); got != "v9.9.9" {
-		t.Errorf("restarted active version = %q, want v9.9.9 (persisted)", got)
+		t.Errorf("restarted active version = %q, want v9.9.9 (a newer out-of-band install is kept)", got)
+	}
+
+	// A redeploy that delivered a build version NEWER than the out-of-band one activates it
+	// for new games without any admin step (the deploy-delivers path — docs/ARCHITECTURE.md §5).
+	if _, err := reg.LoadAvailable(dir, "v10.0.0"); err != nil {
+		t.Fatalf("make v10.0.0 resident: %v", err)
+	}
+	deployed := newGameServiceOn(dir, "v10.0.0", reg)
+	if err := deployed.InitActiveVersion(ctx); err != nil {
+		t.Fatalf("deploy init: %v", err)
+	}
+	if got := deployed.ActiveVersion(); got != "v10.0.0" {
+		t.Errorf("deployed active version = %q, want v10.0.0 (a newer build version wins)", got)
+	}
+	// Restore the out-of-band active version so the assertions below still read v9.9.9.
+	if err := restarted.SetActiveVersion(ctx, "v9.9.9"); err != nil {
+		t.Fatalf("restore active: %v", err)
 	}
 
 	// New games pin the new version; the in-progress game keeps its own, still resident.

backend/internal/inttest/email_test.go

@@ -431,7 +431,7 @@ func TestConfirmByTokenLinkClearsGuest(t *testing.T) {
 	store := account.NewStore(testDB)
 	mailer := &capturingMailer{}
 	svc := account.NewEmailService(store, mailer, "https://erudit-game.ru")
-	guest, err := store.ProvisionGuest(ctx, "")
+	guest, err := store.ProvisionGuest(ctx, "", "")
 	if err != nil {
 		t.Fatalf("provision guest: %v", err)
 	}

backend/internal/inttest/helpers.go

@@ -154,7 +154,7 @@ func provisionAccount(t *testing.T) uuid.UUID {
 // provisionGuest creates a fresh ephemeral guest account and returns its id.
 func provisionGuest(t *testing.T) uuid.UUID {
 	t.Helper()
-	acc, err := account.NewStore(testDB).ProvisionGuest(context.Background(), "")
+	acc, err := account.NewStore(testDB).ProvisionGuest(context.Background(), "", "")
 	if err != nil {
 		t.Fatalf("provision guest: %v", err)
 	}

backend/internal/inttest/merge_test.go

@@ -347,8 +347,10 @@ func TestAccountLinkEmailMergeIntoCaller(t *testing.T) {
 	}
 }
 
-// TestAccountLinkGuestInversion merges a guest initiator into the durable account
+// TestAccountLinkGuestInversion auto-merges a guest initiator into the durable account that
-// that owns the email: the durable account wins and a fresh session is minted.
+// owns the email AT THE CONFIRM STEP (no merge confirmation): the guest is retired, the durable
+// account wins and a fresh session is minted for it (the client adopts the switch and lands on
+// the durable account as if it simply logged in).
 func TestAccountLinkGuestInversion(t *testing.T) {
 	ctx := context.Background()
 	store := account.NewStore(testDB)
@@ -364,17 +366,18 @@ func TestAccountLinkGuestInversion(t *testing.T) {
 		t.Fatalf("request: %v", err)
 	}
 	code := sixDigit.FindString(mailer.lastBody)
-	if _, err := links.ConfirmEmail(ctx, guest, email, code); err != nil {
+	confirm, err := links.ConfirmEmail(ctx, guest, email, code)
+	if err != nil {
 		t.Fatalf("confirm: %v", err)
 	}
-	merge, err := links.MergeEmail(ctx, guest, email, code)
+	// A guest initiator does not get a MergeRequired confirmation — the merge runs inline.
-	if err != nil {
+	if !confirm.Merged || confirm.MergeRequired {
-		t.Fatalf("merge: %v", err)
+		t.Fatalf("confirm = %+v, want an inline (auto) merge", confirm)
 	}
-	if merge.PrimaryID != durable {
+	if confirm.Merge.PrimaryID != durable {
-		t.Fatalf("primary = %s, want durable %s", merge.PrimaryID, durable)
+		t.Fatalf("primary = %s, want durable %s", confirm.Merge.PrimaryID, durable)
 	}
-	if merge.SwitchedToken == "" {
+	if confirm.Merge.SwitchedToken == "" {
 		t.Error("a guest initiator whose durable counterpart wins must get a switched session token")
 	}
 	if mergedInto(t, guest) != durable {
@@ -385,6 +388,33 @@ func TestAccountLinkGuestInversion(t *testing.T) {
 	}
 }
 
+// TestAccountLinkGuestAutoMergeActiveGameConflict guards that a guest's auto-merge is REFUSED
+// (not silently swallowed) at the confirm step when the guest and the durable account share an
+// active game: the caller surfaces ErrActiveGameConflict (mapped to a clear "finish that game
+// first" message) rather than seating one player against themselves.
+func TestAccountLinkGuestAutoMergeActiveGameConflict(t *testing.T) {
+	ctx := context.Background()
+	mailer := &capturingMailer{}
+	links := newLinkService(mailer)
+
+	durable := provisionAccount(t)
+	email := "conflict-" + uuid.NewString() + "@example.com"
+	bindEmailIdentity(t, durable, email)
+	guest := provisionGuest(t)
+	seatGame(t, []uuid.UUID{durable, guest}, 24*time.Hour) // an active game the two share
+
+	if err := links.RequestEmail(ctx, guest, email); err != nil {
+		t.Fatalf("request: %v", err)
+	}
+	code := sixDigit.FindString(mailer.lastBody)
+	if _, err := links.ConfirmEmail(ctx, guest, email, code); err != accountmerge.ErrActiveGameConflict {
+		t.Fatalf("confirm = %v, want ErrActiveGameConflict surfaced by the auto-merge", err)
+	}
+	if mergedInto(t, guest) != uuid.Nil {
+		t.Error("a refused auto-merge must not tombstone the guest")
+	}
+}
+
 // TestAccountLinkFreeVK binds a free VK identity (gateway-validated, no code) and
 // promotes a guest to durable — the ConfirmVK counterpart of the free-email case.
 func TestAccountLinkFreeVK(t *testing.T) {

backend/internal/inttest/payment_availability_test.go

@@ -0,0 +1,83 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/payments"
+)
+
+// TestPaymentAvailabilityKillSwitch exercises the per-rail kill switch + the per-account override
+// end-to-end against Postgres: fail-open, a disabled rail with a localized message, per-rail
+// granularity, and the allow/deny/default overrides.
+func TestPaymentAvailabilityKillSwitch(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+
+	// Fail-open: an untouched rail is enabled.
+	if ok, _, err := svc.CanPurchase(ctx, acc, payments.RailDirectWeb, "en"); err != nil || !ok {
+		t.Fatalf("fail-open: CanPurchase = %v/%v, want true", ok, err)
+	}
+
+	// Disable the web rail with a per-language message → blocked with that message, localized.
+	if err := svc.SetRailStatus(ctx, payments.RailDirectWeb, payments.RailAvailability{MessageRU: "Чиним", MessageEN: "Fixing"}); err != nil {
+		t.Fatalf("set rail status: %v", err)
+	}
+	if ok, reason, err := svc.CanPurchase(ctx, acc, payments.RailDirectWeb, "ru"); err != nil || ok || reason != "Чиним" {
+		t.Fatalf("disabled rail (ru): CanPurchase = %v/%q/%v, want false/Чиним", ok, reason, err)
+	}
+	if ok, reason, _ := svc.CanPurchase(ctx, acc, payments.RailDirectWeb, "en"); ok || reason != "Fixing" {
+		t.Fatalf("disabled rail (en): = %v/%q, want false/Fixing", ok, reason)
+	}
+	// Per-rail granularity: another rail stays enabled.
+	if ok, _, _ := svc.CanPurchase(ctx, acc, payments.RailDirectAndroid, "en"); !ok {
+		t.Fatalf("android rail should stay enabled")
+	}
+
+	// A per-account "allow" override bypasses the disabled rail.
+	if err := svc.SetPurchaseOverride(ctx, acc, payments.OverrideAllow); err != nil {
+		t.Fatalf("set override allow: %v", err)
+	}
+	if ok, _, _ := svc.CanPurchase(ctx, acc, payments.RailDirectWeb, "en"); !ok {
+		t.Fatalf("allow override should bypass the disabled rail")
+	}
+	if ov, err := svc.PurchaseOverrideFor(ctx, acc); err != nil || ov != payments.OverrideAllow {
+		t.Fatalf("PurchaseOverrideFor = %v/%v, want allow", ov, err)
+	}
+
+	// A "deny" override blocks even an enabled rail.
+	if err := svc.SetPurchaseOverride(ctx, acc, payments.OverrideDeny); err != nil {
+		t.Fatalf("set override deny: %v", err)
+	}
+	if ok, reason, _ := svc.CanPurchase(ctx, acc, payments.RailDirectAndroid, "en"); ok || reason == "" {
+		t.Fatalf("deny override should block the enabled android rail with a reason, got %v/%q", ok, reason)
+	}
+
+	// Clearing the override (default) restores rail-driven behaviour.
+	if err := svc.SetPurchaseOverride(ctx, acc, payments.OverrideDefault); err != nil {
+		t.Fatalf("clear override: %v", err)
+	}
+	if ov, _ := svc.PurchaseOverrideFor(ctx, acc); ov != payments.OverrideDefault {
+		t.Fatalf("after clear, override = %v, want default", ov)
+	}
+	if ok, _, _ := svc.CanPurchase(ctx, acc, payments.RailDirectAndroid, "en"); !ok {
+		t.Fatalf("after clearing override, android rail should be enabled again")
+	}
+
+	// RailStatuses reflects the stored web-rail change and fills the rest fail-open.
+	all, err := svc.RailStatuses(ctx)
+	if err != nil {
+		t.Fatalf("rail statuses: %v", err)
+	}
+	if all[payments.RailDirectWeb].Enabled {
+		t.Fatalf("web rail should read disabled")
+	}
+	if !all[payments.RailVK].Enabled {
+		t.Fatalf("untouched vk rail should read enabled")
+	}
+}

backend/internal/inttest/userlist_test.go

@@ -26,7 +26,7 @@ func TestUserListFilter(t *testing.T) {
 	if err != nil {
 		t.Fatalf("provision robot: %v", err)
 	}
-	guest, err := st.ProvisionGuest(ctx, "")
+	guest, err := st.ProvisionGuest(ctx, "", "")
 	if err != nil {
 		t.Fatalf("provision guest: %v", err)
 	}

backend/internal/link/service.go

@@ -31,13 +31,39 @@ func NewService(emails *account.EmailService, accounts *account.Store, merger *a
 	return &Service{emails: emails, accounts: accounts, merger: merger, sessions: sessions}
 }
 
-// ConfirmResult reports the outcome of a confirm step. Exactly one of Linked or
+// ConfirmResult reports the outcome of a confirm step. Exactly one of Linked,
-// MergeRequired is set; SecondaryID is the account to be retired when a merge is
+// MergeRequired or Merged is set. SecondaryID is the account to be retired when a merge
-// required (the caller renders an irreversible-merge confirmation from it).
+// is required (the caller renders an irreversible-merge confirmation from it). Merged is
+// set when the caller was a guest, so the merge ran inline (see confirmOrAutoMerge) and
+// Merge carries its result (the switched-session token for the surviving durable account).
 type ConfirmResult struct {
 	Linked        bool
 	MergeRequired bool
 	SecondaryID   uuid.UUID
+	Merged        bool
+	Merge         MergeResult
+}
+
+// confirmOrAutoMerge decides a required merge at the confirm step. A durable caller gets
+// the explicit MergeRequired confirmation (consolidating two real accounts is irreversible
+// and consequential — the user must see it). A GUEST caller does not: by the guest-primary
+// rule the durable other account survives and the ephemeral guest is retired, folding its
+// games/wallet/stats in — from the user's side it is simply "logged into my account", so the
+// merge runs inline and the client just adopts the switched session. The active-game guard can
+// still refuse (accountmerge.ErrActiveGameConflict), surfaced to the caller unchanged.
+func (s *Service) confirmOrAutoMerge(ctx context.Context, callerID, owner uuid.UUID) (ConfirmResult, error) {
+	caller, err := s.accounts.GetByID(ctx, callerID)
+	if err != nil {
+		return ConfirmResult{}, err
+	}
+	if !caller.IsGuest {
+		return ConfirmResult{MergeRequired: true, SecondaryID: owner}, nil
+	}
+	res, err := s.merge(ctx, callerID, owner)
+	if err != nil {
+		return ConfirmResult{}, err
+	}
+	return ConfirmResult{Merged: true, Merge: res}, nil
 }
 
 // MergeResult reports a completed merge. PrimaryID is the surviving account.
@@ -67,7 +93,7 @@ func (s *Service) ConfirmEmail(ctx context.Context, accountID uuid.UUID, email,
 		}
 		return ConfirmResult{Linked: true}, nil
 	}
-	return ConfirmResult{MergeRequired: true, SecondaryID: owner}, nil
+	return s.confirmOrAutoMerge(ctx, accountID, owner)
 }
 
 // MergeEmail re-verifies the code and merges the address's account into the
@@ -103,7 +129,7 @@ func (s *Service) ConfirmTelegram(ctx context.Context, callerID uuid.UUID, exter
 	if owner == callerID {
 		return ConfirmResult{Linked: true}, nil
 	}
-	return ConfirmResult{MergeRequired: true, SecondaryID: owner}, nil
+	return s.confirmOrAutoMerge(ctx, callerID, owner)
 }
 
 // MergeTelegram merges the account owning a gateway-validated Telegram identity
@@ -150,7 +176,7 @@ func (s *Service) ConfirmVK(ctx context.Context, callerID uuid.UUID, externalID
 	if owner == callerID {
 		return ConfirmResult{Linked: true}, nil
 	}
-	return ConfirmResult{MergeRequired: true, SecondaryID: owner}, nil
+	return s.confirmOrAutoMerge(ctx, callerID, owner)
 }
 
 // MergeVK merges the account owning a gateway-validated VK identity into the caller's

backend/internal/payments/availability.go

@@ -0,0 +1,107 @@
+package payments
+
+import "slices"
+
+// PurchaseOverride is a per-account purchase override that forces purchases allowed or denied for
+// one account regardless of the operational rail switch, or is absent (OverrideDefault) when the
+// account follows the rail switch. The zero value is OverrideDefault, so a missing override row maps
+// to it. OverrideAllow bypasses ONLY the operational rail switch — never the security / compliance
+// gates (trusted platform, the D36 email anchor, the VK-iOS spend freeze, the min client version),
+// which CreateOrder enforces separately.
+type PurchaseOverride int
+
+const (
+	// OverrideDefault follows the rail switch (no override row for the account).
+	OverrideDefault PurchaseOverride = iota
+	// OverrideAllow always allows the purchase, bypassing only the operational rail switch.
+	OverrideAllow
+	// OverrideDeny always denies the purchase for the account.
+	OverrideDeny
+)
+
+// RailAvailability is a payment rail's operational availability: whether purchases are enabled and,
+// when disabled, the operator's explanation in each language, shown to the user on a purchase
+// attempt. A rail with no status row is treated as enabled (fail-open — see the store), so the
+// zero value is never used as a live "enabled" default.
+type RailAvailability struct {
+	Enabled   bool
+	MessageRU string
+	MessageEN string
+}
+
+// PurchaseGate decides whether an account may open a purchase order on a rail, from the per-account
+// override and the rail's operational availability. It is the operational layer only — the caller
+// still enforces the security gates. On a block it returns a reason localized to lang ("ru", else
+// English). Fail-open: OverrideDefault on an enabled rail allows.
+func PurchaseGate(override PurchaseOverride, rail RailAvailability, lang string) (ok bool, reason string) {
+	switch override {
+	case OverrideAllow:
+		return true, "" // bypasses only the ops switch; the security gates still apply upstream
+	case OverrideDeny:
+		return false, defaultUnavailable(lang) // a per-account block — a neutral reason
+	default: // OverrideDefault — follow the rail switch
+		if rail.Enabled {
+			return true, ""
+		}
+		return false, railMessage(rail, lang)
+	}
+}
+
+// railMessage returns the operator's rail-off message in lang, falling back to the other language
+// and then to the built-in default when the operator left both blank.
+func railMessage(rail RailAvailability, lang string) string {
+	if lang == "ru" {
+		if rail.MessageRU != "" {
+			return rail.MessageRU
+		}
+		if rail.MessageEN != "" {
+			return rail.MessageEN
+		}
+	} else {
+		if rail.MessageEN != "" {
+			return rail.MessageEN
+		}
+		if rail.MessageRU != "" {
+			return rail.MessageRU
+		}
+	}
+	return defaultUnavailable(lang)
+}
+
+// defaultUnavailable is the built-in localized "payments unavailable" reason used when the operator
+// set no custom message, and for a per-account deny.
+func defaultUnavailable(lang string) string {
+	if lang == "ru" {
+		return "Оплата временно недоступна. Попробуйте позже."
+	}
+	return "Payments are temporarily unavailable. Please try again later."
+}
+
+// Rail keys name the operational payment rails the kill switch and the per-account override key on.
+// The direct rail is split per channel (D42); vk and telegram are single-rail.
+const (
+	RailDirectWeb     = "direct:web"
+	RailDirectAndroid = "direct:android"
+	RailVK            = "vk"
+	RailTelegram      = "telegram"
+)
+
+// KnownRails is the fixed set of rail keys, for the admin editor and for validation.
+var KnownRails = []string{RailDirectWeb, RailDirectAndroid, RailVK, RailTelegram}
+
+// RailKey maps a payment context to its operational rail key: the direct rail by channel subtype
+// (android, else web), or the store rail's own name (vk / telegram).
+func RailKey(kind Source, subtype string) string {
+	if kind == SourceDirect {
+		if subtype == "android" {
+			return RailDirectAndroid
+		}
+		return RailDirectWeb
+	}
+	return string(kind)
+}
+
+// isKnownRail reports whether rail is one of the fixed rail keys.
+func isKnownRail(rail string) bool {
+	return slices.Contains(KnownRails, rail)
+}

backend/internal/payments/availability_test.go

@@ -0,0 +1,40 @@
+package payments
+
+import "testing"
+
+func TestPurchaseGate(t *testing.T) {
+	on := RailAvailability{Enabled: true}
+	offMsg := RailAvailability{Enabled: false, MessageRU: "Чиним", MessageEN: "Fixing"}
+	offNoMsg := RailAvailability{Enabled: false}
+
+	// OverrideDefault follows the rail switch.
+	if ok, _ := PurchaseGate(OverrideDefault, on, "en"); !ok {
+		t.Error("default + enabled rail should allow")
+	}
+	if ok, r := PurchaseGate(OverrideDefault, offMsg, "ru"); ok || r != "Чиним" {
+		t.Errorf("default + off rail (ru) = %v/%q, want false/Чиним", ok, r)
+	}
+	if ok, r := PurchaseGate(OverrideDefault, offMsg, "en"); ok || r != "Fixing" {
+		t.Errorf("default + off rail (en) = %v/%q, want false/Fixing", ok, r)
+	}
+
+	// Off rail with no custom message → the built-in default, localized (not the English default in ru).
+	if ok, r := PurchaseGate(OverrideDefault, offNoMsg, "ru"); ok || r != defaultUnavailable("ru") {
+		t.Errorf("default + off no-msg (ru) = %v/%q, want false + the ru default", ok, r)
+	}
+
+	// OverrideAllow bypasses the ops switch even when the rail is off.
+	if ok, r := PurchaseGate(OverrideAllow, offMsg, "en"); !ok || r != "" {
+		t.Errorf("allow + off rail = %v/%q, want true/empty (bypasses the ops switch)", ok, r)
+	}
+
+	// OverrideDeny blocks even when the rail is on, with a non-empty reason.
+	if ok, r := PurchaseGate(OverrideDeny, on, "en"); ok || r == "" {
+		t.Errorf("deny + on rail = %v/%q, want false + a reason", ok, r)
+	}
+
+	// The message falls back to the other language when only one is set.
+	if _, r := PurchaseGate(OverrideDefault, RailAvailability{MessageEN: "OnlyEN"}, "ru"); r != "OnlyEN" {
+		t.Errorf("off rail ru with only EN msg = %q, want OnlyEN (fallback)", r)
+	}
+}

backend/internal/payments/service_availability.go

@@ -0,0 +1,63 @@
+package payments
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+// CanPurchase reports whether an account may open a purchase order on rail, combining the account's
+// per-account override with the rail's operational switch (PurchaseGate). It is the operational
+// availability layer only — the caller still enforces the security gates (trusted platform, the D36
+// email anchor, the VK-iOS spend freeze, the min client version). On a block, reason is localized to
+// lang for the user; err is only a store failure.
+func (s *Service) CanPurchase(ctx context.Context, accountID uuid.UUID, rail, lang string) (ok bool, reason string, err error) {
+	ov, err := s.store.purchaseOverride(ctx, accountID)
+	if err != nil {
+		return false, "", err
+	}
+	avail, err := s.store.railAvailability(ctx, rail)
+	if err != nil {
+		return false, "", err
+	}
+	ok, reason = PurchaseGate(ov, avail, lang)
+	return ok, reason, nil
+}
+
+// RailStatuses returns every known rail's operational status for the admin editor, filling a rail
+// with no stored row with the fail-open enabled default so the editor always shows one row per rail.
+func (s *Service) RailStatuses(ctx context.Context) (map[string]RailAvailability, error) {
+	stored, err := s.store.allRailStatus(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[string]RailAvailability, len(KnownRails))
+	for _, rail := range KnownRails {
+		if a, ok := stored[rail]; ok {
+			out[rail] = a
+		} else {
+			out[rail] = RailAvailability{Enabled: true}
+		}
+	}
+	return out, nil
+}
+
+// SetRailStatus upserts a rail's operational status from the admin editor. It rejects an unknown rail
+// key so a typo cannot create a dead row.
+func (s *Service) SetRailStatus(ctx context.Context, rail string, a RailAvailability) error {
+	if !isKnownRail(rail) {
+		return fmt.Errorf("payments: unknown rail %q", rail)
+	}
+	return s.store.setRailStatus(ctx, rail, a, s.clock())
+}
+
+// PurchaseOverrideFor returns an account's purchase override (OverrideDefault when none is set).
+func (s *Service) PurchaseOverrideFor(ctx context.Context, accountID uuid.UUID) (PurchaseOverride, error) {
+	return s.store.purchaseOverride(ctx, accountID)
+}
+
+// SetPurchaseOverride sets or clears an account's purchase override (OverrideDefault deletes the row).
+func (s *Service) SetPurchaseOverride(ctx context.Context, accountID uuid.UUID, ov PurchaseOverride) error {
+	return s.store.setPurchaseOverride(ctx, accountID, ov, s.clock())
+}

backend/internal/payments/service_intake.go

@@ -46,6 +46,7 @@ func (s *Service) CreateOrder(ctx context.Context, accountID uuid.UUID, cxt Cont
 		amount:    pack.price,
 		origin:    method,
 		provider:  provider,
+		shop:      directShop(cxt),
 	}
 	if err := s.store.createOrder(ctx, o, s.clock()); err != nil {
 		return OrderResult{}, err
@@ -53,6 +54,16 @@ func (s *Service) CreateOrder(ctx context.Context, accountID uuid.UUID, cxt Cont
 	return OrderResult{OrderID: orderID, Amount: pack.price, Title: pack.title}, nil
 }
 
+// directShop returns the merchant shop (channel) a direct order is issued through — the trusted
+// platform subtype for the direct rail ("web"/"android"), or "" for any other rail (the per-shop
+// split is direct-only; D42/D44). Recorded on the order for the admin per-channel breakdown.
+func directShop(cxt Context) string {
+	if cxt.Kind == SourceDirect {
+		return cxt.Subtype
+	}
+	return ""
+}
+
 // OrderItem returns a pending order's human title and the amount it charges, in the order's own
 // currency — the details a provider's item-lookup phase needs (VK's get_item). It reads the order
 // and the pack title, honouring the pack even if it was later deactivated (mirrors Fund).

backend/internal/payments/statement.go

@@ -42,7 +42,8 @@ type RiskInfo struct {
 }
 
 // LedgerEntry is one append-only ledger row projected for the report. The string ids are empty when
-// the column is NULL; Snapshot is the raw purchase/refund JSON (empty when none).
+// the column is NULL; Shop is the direct-rail merchant channel the referenced order used (empty for
+// other rails or order-less rows); Snapshot is the raw purchase/refund JSON (empty when none).
 type LedgerEntry struct {
 	Kind              string
 	Source            string
@@ -52,6 +53,7 @@ type LedgerEntry struct {
 	OrderID           string
 	Provider          string
 	ProviderPaymentID string
+	Shop              string
 	Snapshot          string
 	CreatedAt         time.Time
 }

backend/internal/payments/store_availability.go

@@ -0,0 +1,96 @@
+package payments
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// railAvailability reads a rail's operational availability. A missing row is fail-open: enabled with
+// no message, so payments stay on unless an operator explicitly disabled the rail.
+func (s *Store) railAvailability(ctx context.Context, rail string) (RailAvailability, error) {
+	var a RailAvailability
+	err := s.db.QueryRowContext(ctx,
+		`SELECT enabled, message_ru, message_en FROM payments.rail_status WHERE rail = $1`, rail).
+		Scan(&a.Enabled, &a.MessageRU, &a.MessageEN)
+	if errors.Is(err, sql.ErrNoRows) {
+		return RailAvailability{Enabled: true}, nil
+	}
+	if err != nil {
+		return RailAvailability{}, fmt.Errorf("payments: read rail status %q: %w", rail, err)
+	}
+	return a, nil
+}
+
+// allRailStatus reads every stored rail-status row for the admin editor, keyed by rail. Rails with
+// no row are absent (the caller fills them with the fail-open enabled default).
+func (s *Store) allRailStatus(ctx context.Context) (map[string]RailAvailability, error) {
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT rail, enabled, message_ru, message_en FROM payments.rail_status`)
+	if err != nil {
+		return nil, fmt.Errorf("payments: read rail statuses: %w", err)
+	}
+	defer rows.Close()
+	out := make(map[string]RailAvailability)
+	for rows.Next() {
+		var rail string
+		var a RailAvailability
+		if err := rows.Scan(&rail, &a.Enabled, &a.MessageRU, &a.MessageEN); err != nil {
+			return nil, fmt.Errorf("payments: scan rail status: %w", err)
+		}
+		out[rail] = a
+	}
+	return out, rows.Err()
+}
+
+// setRailStatus upserts a rail's operational status (admin).
+func (s *Store) setRailStatus(ctx context.Context, rail string, a RailAvailability, now time.Time) error {
+	if _, err := s.db.ExecContext(ctx,
+		`INSERT INTO payments.rail_status (rail, enabled, message_ru, message_en, updated_at)
+		 VALUES ($1, $2, $3, $4, $5)
+		 ON CONFLICT (rail) DO UPDATE SET enabled = $2, message_ru = $3, message_en = $4, updated_at = $5`,
+		rail, a.Enabled, a.MessageRU, a.MessageEN, now); err != nil {
+		return fmt.Errorf("payments: set rail status %q: %w", rail, err)
+	}
+	return nil
+}
+
+// purchaseOverride reads an account's purchase override; a missing row is OverrideDefault.
+func (s *Store) purchaseOverride(ctx context.Context, accountID uuid.UUID) (PurchaseOverride, error) {
+	var allow bool
+	err := s.db.QueryRowContext(ctx,
+		`SELECT allow FROM payments.account_payment_override WHERE account_id = $1`, accountID).Scan(&allow)
+	if errors.Is(err, sql.ErrNoRows) {
+		return OverrideDefault, nil
+	}
+	if err != nil {
+		return OverrideDefault, fmt.Errorf("payments: read purchase override %s: %w", accountID, err)
+	}
+	if allow {
+		return OverrideAllow, nil
+	}
+	return OverrideDeny, nil
+}
+
+// setPurchaseOverride upserts an account's override, or deletes the row for OverrideDefault (the
+// default state is the absence of a row).
+func (s *Store) setPurchaseOverride(ctx context.Context, accountID uuid.UUID, ov PurchaseOverride, now time.Time) error {
+	if ov == OverrideDefault {
+		if _, err := s.db.ExecContext(ctx,
+			`DELETE FROM payments.account_payment_override WHERE account_id = $1`, accountID); err != nil {
+			return fmt.Errorf("payments: clear purchase override %s: %w", accountID, err)
+		}
+		return nil
+	}
+	if _, err := s.db.ExecContext(ctx,
+		`INSERT INTO payments.account_payment_override (account_id, allow, updated_at) VALUES ($1, $2, $3)
+		 ON CONFLICT (account_id) DO UPDATE SET allow = $2, updated_at = $3`,
+		accountID, ov == OverrideAllow, now); err != nil {
+		return fmt.Errorf("payments: set purchase override %s: %w", accountID, err)
+	}
+	return nil
+}

backend/internal/payments/store_intake.go

@@ -151,6 +151,7 @@ type newOrder struct {
 	amount    Money
 	origin    Source
 	provider  string
+	shop      string
 }
 
 // createOrder inserts a pending order.
@@ -159,12 +160,12 @@ func (s *Store) createOrder(ctx context.Context, o newOrder, now time.Time) erro
 		table.Orders.OrderID, table.Orders.AccountID, table.Orders.Platform,
 		table.Orders.ProductID, table.Orders.ExpectedAmount, table.Orders.Currency,
 		table.Orders.Origin, table.Orders.Status, table.Orders.Provider,
-		table.Orders.CreatedAt, table.Orders.UpdatedAt,
+		table.Orders.CreatedAt, table.Orders.UpdatedAt, table.Orders.Shop,
 	).VALUES(
 		o.orderID, o.accountID, o.platform,
 		o.productID, o.amount.Minor(), string(o.amount.Currency()),
 		string(o.origin), "pending", o.provider,
-		now, now,
+		now, now, o.shop,
 	)
 	if _, err := stmt.ExecContext(ctx, s.db); err != nil {
 		return fmt.Errorf("payments: create order: %w", err)

backend/internal/payments/store_statement.go

@@ -74,9 +74,39 @@ func (s *Store) accountStatement(ctx context.Context, accountID uuid.UUID) (Stat
 			CreatedAt:         r.CreatedAt,
 		})
 	}
+
+	// Annotate direct-rail entries with the merchant shop (channel) their order was issued through
+	// (E10/D44), keyed by the ledger's order id. Non-direct / order-less entries stay "".
+	shops, err := s.orderShops(ctx, accountID)
+	if err != nil {
+		return Statement{}, err
+	}
+	for i := range out.Ledger {
+		out.Ledger[i].Shop = shops[out.Ledger[i].OrderID]
+	}
 	return out, nil
 }
 
+// orderShops maps an account's order ids (as strings) to the merchant shop (channel) each direct
+// order was issued through, for annotating the ledger report (E10/D44). Orders with an empty shop
+// (non-direct or pre-split) are omitted, so a lookup miss yields "".
+func (s *Store) orderShops(ctx context.Context, accountID uuid.UUID) (map[string]string, error) {
+	var rows []model.Orders
+	if err := postgres.SELECT(table.Orders.OrderID, table.Orders.Shop).
+		FROM(table.Orders).
+		WHERE(table.Orders.AccountID.EQ(postgres.UUID(accountID))).
+		QueryContext(ctx, s.db, &rows); err != nil {
+		return nil, fmt.Errorf("payments: load order shops %s: %w", accountID, err)
+	}
+	m := make(map[string]string, len(rows))
+	for _, r := range rows {
+		if r.Shop != "" {
+			m[r.OrderID.String()] = r.Shop
+		}
+	}
+	return m, nil
+}
+
 // allLedger reads the entire append-only ledger (all accounts, newest first) for the admin export.
 func (s *Store) allLedger(ctx context.Context) ([]LedgerExportRow, error) {
 	var rows []model.Ledger

backend/internal/postgres/jet/payments/model/orders.go

@@ -25,4 +25,5 @@ type Orders struct {
 	ProviderPaymentID *string
 	CreatedAt         time.Time
 	UpdatedAt         time.Time
+	Shop              string
 }

backend/internal/postgres/jet/payments/table/orders.go

@@ -29,6 +29,7 @@ type ordersTable struct {
 	ProviderPaymentID postgres.ColumnString
 	CreatedAt         postgres.ColumnTimestampz
 	UpdatedAt         postgres.ColumnTimestampz
+	Shop              postgres.ColumnString
 
 	AllColumns     postgres.ColumnList
 	MutableColumns postgres.ColumnList
@@ -82,9 +83,10 @@ func newOrdersTableImpl(schemaName, tableName, alias string) ordersTable {
 		ProviderPaymentIDColumn = postgres.StringColumn("provider_payment_id")
 		CreatedAtColumn         = postgres.TimestampzColumn("created_at")
 		UpdatedAtColumn         = postgres.TimestampzColumn("updated_at")
-		allColumns              = postgres.ColumnList{OrderIDColumn, AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn}
+		ShopColumn              = postgres.StringColumn("shop")
-		mutableColumns          = postgres.ColumnList{AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn}
+		allColumns              = postgres.ColumnList{OrderIDColumn, AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn, ShopColumn}
-		defaultColumns          = postgres.ColumnList{StatusColumn, CreatedAtColumn, UpdatedAtColumn}
+		mutableColumns          = postgres.ColumnList{AccountIDColumn, PlatformColumn, ProductIDColumn, ExpectedAmountColumn, CurrencyColumn, OriginColumn, StatusColumn, ProviderColumn, ProviderPaymentIDColumn, CreatedAtColumn, UpdatedAtColumn, ShopColumn}
+		defaultColumns          = postgres.ColumnList{StatusColumn, CreatedAtColumn, UpdatedAtColumn, ShopColumn}
 	)
 
 	return ordersTable{
@@ -103,6 +105,7 @@ func newOrdersTableImpl(schemaName, tableName, alias string) ordersTable {
 		ProviderPaymentID: ProviderPaymentIDColumn,
 		CreatedAt:         CreatedAtColumn,
 		UpdatedAt:         UpdatedAtColumn,
+		Shop:              ShopColumn,
 
 		AllColumns:     allColumns,
 		MutableColumns: mutableColumns,

backend/internal/postgres/migrations/00015_orders_shop.sql

@@ -0,0 +1,13 @@
+-- Multi-shop direct rail (E10/D44): record which Robokassa merchant shop (channel) issued a direct
+-- order — "web" / "android" (ios later) — so the admin financial report can break direct payments
+-- down by channel. Only the direct rail is per-channel; other rails leave it "". Additive only (a
+-- defaulted column), applies forward via goose with no data rewrite (no contour wipe); an image
+-- rollback ignores the column.
+-- +goose Up
+
+ALTER TABLE payments.orders
+    ADD COLUMN shop text NOT NULL DEFAULT '';
+
+-- +goose Down
+
+ALTER TABLE payments.orders DROP COLUMN shop;

backend/internal/postgres/migrations/00016_payment_availability.sql

@@ -0,0 +1,26 @@
+-- Payment availability controls (D45/D46): a per-rail operational kill switch with a localized message,
+-- and a per-account purchase override. Both let an operator disable payments live from the admin —
+-- a whole rail/channel, or one account — and explain why to the user on a purchase attempt. Additive
+-- (new tables) — applies forward via goose with no data rewrite (no contour wipe); an image rollback
+-- ignores both tables. Fail-open by design: a rail with no row is enabled; an account with no row
+-- follows the rail switch.
+-- +goose Up
+
+CREATE TABLE payments.rail_status (
+    rail text PRIMARY KEY,
+    enabled boolean NOT NULL DEFAULT true,
+    message_ru text NOT NULL DEFAULT '',
+    message_en text NOT NULL DEFAULT '',
+    updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE TABLE payments.account_payment_override (
+    account_id uuid PRIMARY KEY,
+    allow boolean NOT NULL,
+    updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+-- +goose Down
+
+DROP TABLE payments.account_payment_override;
+DROP TABLE payments.rail_status;

backend/internal/robokassa/shops.go

@@ -0,0 +1,54 @@
+package robokassa
+
+// Shops is a set of Robokassa merchant shops keyed by channel — the subtype of the trusted
+// X-Platform signal for the direct rail ("web", "android"; "ios" later). The direct rail routes a
+// payment to the per-channel shop for separate merchant accounts, accounting and receipts, while
+// every shop still credits the one direct wallet (docs/PAYMENTS_DECISIONS_ru.md D42). An empty set
+// leaves the direct order and Result-callback endpoints unregistered.
+type Shops map[string]Config
+
+// Channel constants name the direct-rail X-Platform subtypes a shop is keyed by. ChannelWeb is the
+// default: an unknown or empty channel routes here on the order side, and the legacy single-shop
+// configuration seeds it.
+const (
+	ChannelWeb     = "web"
+	ChannelAndroid = "android"
+)
+
+// Shop returns the shop that issues an order for channel, falling back to the web shop when channel
+// is unknown, empty or not configured. The fallback is safe: routing only chooses the merchant
+// account and receipt, never the credited wallet (always direct, D42), so a mis-attributed channel
+// costs at most accounting accuracy, not money. The second result is false when neither the channel
+// nor the web shop has a merchant login (the rail is unconfigured).
+func (s Shops) Shop(channel string) (Config, bool) {
+	if channel != "" {
+		if c, ok := s[channel]; ok && c.MerchantLogin != "" {
+			return c, true
+		}
+	}
+	if c, ok := s[ChannelWeb]; ok && c.MerchantLogin != "" {
+		return c, true
+	}
+	return Config{}, false
+}
+
+// Verifier returns the shop whose Password2 verifies a Result callback delivered to channel's
+// dedicated Result route. Unlike Shop it does not fall back to web: each shop's callback is verified
+// only by that shop's own credentials, so a route with no configured shop reports false (and its
+// handler answers as unregistered). The second result is false when channel has no merchant login.
+func (s Shops) Verifier(channel string) (Config, bool) {
+	if c, ok := s[channel]; ok && c.MerchantLogin != "" {
+		return c, true
+	}
+	return Config{}, false
+}
+
+// Configured reports whether at least one shop has a merchant login (the direct rail is live).
+func (s Shops) Configured() bool {
+	for _, c := range s {
+		if c.MerchantLogin != "" {
+			return true
+		}
+	}
+	return false
+}

backend/internal/robokassa/shops_test.go

@@ -0,0 +1,52 @@
+package robokassa
+
+import "testing"
+
+func TestShopsShopRouting(t *testing.T) {
+	shops := Shops{
+		ChannelWeb:     {MerchantLogin: "webshop", Password1: "w1", Password2: "w2"},
+		ChannelAndroid: {MerchantLogin: "androidshop", Password1: "a1", Password2: "a2"},
+	}
+	// Order side: the exact channel wins.
+	if c, ok := shops.Shop(ChannelAndroid); !ok || c.MerchantLogin != "androidshop" {
+		t.Errorf("Shop(android) = %q/%v, want androidshop/true", c.MerchantLogin, ok)
+	}
+	// Order side: an unknown or empty channel falls back to the web shop (safe — always credits direct).
+	if c, ok := shops.Shop("ios"); !ok || c.MerchantLogin != "webshop" {
+		t.Errorf("Shop(ios) = %q/%v, want webshop/true (web fallback)", c.MerchantLogin, ok)
+	}
+	if c, ok := shops.Shop(""); !ok || c.MerchantLogin != "webshop" {
+		t.Errorf("Shop(empty) = %q/%v, want webshop/true (web fallback)", c.MerchantLogin, ok)
+	}
+	// No web shop and an unknown channel → unconfigured.
+	if _, ok := (Shops{ChannelAndroid: {MerchantLogin: "androidshop", Password1: "a1", Password2: "a2"}}).Shop("ios"); ok {
+		t.Error("Shop(ios) with no web shop returned ok, want false")
+	}
+}
+
+func TestShopsVerifierIsStrict(t *testing.T) {
+	shops := Shops{
+		ChannelWeb:     {MerchantLogin: "webshop", Password1: "w1", Password2: "w2"},
+		ChannelAndroid: {MerchantLogin: "androidshop", Password1: "a1", Password2: "a2"},
+	}
+	// Callback side: the exact channel's own credentials, no web fallback (each callback is verified
+	// only by its own shop's Password2).
+	if c, ok := shops.Verifier(ChannelAndroid); !ok || c.MerchantLogin != "androidshop" {
+		t.Errorf("Verifier(android) = %q/%v, want androidshop/true", c.MerchantLogin, ok)
+	}
+	if _, ok := shops.Verifier("ios"); ok {
+		t.Error("Verifier(ios) returned ok, want false (no fallback)")
+	}
+}
+
+func TestShopsConfigured(t *testing.T) {
+	if (Shops{}).Configured() {
+		t.Error("an empty set reported configured")
+	}
+	if (Shops{ChannelWeb: {}}).Configured() {
+		t.Error("a shop with no merchant login reported configured")
+	}
+	if !(Shops{ChannelWeb: {MerchantLogin: "s", Password1: "1", Password2: "2"}}).Configured() {
+		t.Error("a configured shop reported not configured")
+	}
+}

backend/internal/server/handlers.go

@@ -89,7 +89,7 @@ func (s *Server) registerRoutes() {
 		// payment over the reverse bot-link; the gateway proxies both onto these gateway-only routes.
 		s.internal.POST("/payments/telegram/precheckout", s.handleTelegramPreCheckout)
 		s.internal.POST("/payments/telegram/payment", s.handleTelegramPayment)
-		if s.robokassa.MerchantLogin != "" {
+		if s.robokassa.Configured() {
 			s.internal.POST("/payments/robokassa/result", s.handleRobokassaResult)
 		}
 	}

backend/internal/server/handlers_admin_catalog.go

@@ -51,7 +51,16 @@ func (s *Server) consoleCatalog(c *gin.Context) {
 		s.consoleError(c, err)
 		return
 	}
+	rails, err := s.payments.RailStatuses(c.Request.Context())
+	if err != nil {
+		s.consoleError(c, err)
+		return
+	}
 	view := adminconsole.CatalogView{ShowAll: showAll, RewardPayout: payout, RewardDailyCap: daily, RewardHourlyCap: hourly}
+	for _, rail := range payments.KnownRails {
+		a := rails[rail]
+		view.Rails = append(view.Rails, adminconsole.RailStatusRow{Rail: rail, Enabled: a.Enabled, MessageRU: a.MessageRU, MessageEN: a.MessageEN})
+	}
 	for _, p := range products {
 		view.Products = append(view.Products, catalogRow(p))
 	}
@@ -72,6 +81,23 @@ func (s *Server) consoleSetReward(c *gin.Context) {
 	s.renderConsoleMessage(c, "Saved", "the rewarded-ads config was updated", catalogBack)
 }
 
+// consoleSetRailStatus toggles a payment rail's operational kill switch and its user-facing
+// off-message (per language) from the catalog page's payment-availability form. An unchecked box
+// disables the rail; an unknown rail is refused by the service.
+func (s *Server) consoleSetRailStatus(c *gin.Context) {
+	rail := strings.TrimSpace(c.PostForm("rail"))
+	a := payments.RailAvailability{
+		Enabled:   c.PostForm("enabled") == "on",
+		MessageRU: strings.TrimSpace(c.PostForm("message_ru")),
+		MessageEN: strings.TrimSpace(c.PostForm("message_en")),
+	}
+	if err := s.payments.SetRailStatus(c.Request.Context(), rail, a); err != nil {
+		s.renderConsoleMessage(c, "Update failed", err.Error(), catalogBack)
+		return
+	}
+	s.renderConsoleMessage(c, "Saved", "payment availability was updated", catalogBack)
+}
+
 // catalogRow projects a product into its list row.
 func catalogRow(p payments.AdminProduct) adminconsole.ProductRow {
 	row := adminconsole.ProductRow{ID: p.ID.String(), Title: p.Title, Active: p.Active, Transacted: p.Transacted}

backend/internal/server/handlers_admin_console.go

@@ -61,6 +61,7 @@ func (s *Server) registerConsole(router *gin.Engine) {
 	gm.POST("/users/:id/grant", s.consoleGrant)
 	gm.POST("/users/:id/grant-product", s.consoleGrantProduct)
 	gm.POST("/users/:id/refund", s.consoleRefund)
+	gm.POST("/users/:id/purchase-override", s.consoleSetPurchaseOverride)
 	gm.POST("/users/:id/delete", s.consoleDeleteUser)
 	gm.GET("/reasons", s.consoleReasons)
 	gm.POST("/reasons", s.consoleCreateReason)
@@ -113,6 +114,7 @@ func (s *Server) registerConsole(router *gin.Engine) {
 		gm.GET("/catalog", s.consoleCatalog)
 		gm.POST("/catalog", s.consoleCreateProduct)
 		gm.POST("/catalog/reward", s.consoleSetReward)
+		gm.POST("/catalog/rail-status", s.consoleSetRailStatus)
 		gm.GET("/catalog/:id", s.consoleCatalogDetail)
 		gm.POST("/catalog/:id", s.consoleUpdateProduct)
 		gm.POST("/catalog/:id/archive", s.consoleArchiveProduct)
@@ -461,6 +463,9 @@ func (s *Server) consoleUserDetail(c *gin.Context) {
 			s.log.Warn("console: account statement failed", zap.String("account", id.String()), zap.Error(err))
 		}
 		view.Grant = s.grantForm(ctx)
+		if ov, oerr := s.payments.PurchaseOverrideFor(ctx, id); oerr == nil {
+			view.PurchaseOverride = overrideName(ov)
+		}
 	}
 	s.renderConsole(c, "user_detail", "users", acc.DisplayName, view)
 }
@@ -482,13 +487,54 @@ func financeView(stmt payments.Statement) adminconsole.FinanceView {
 	for _, e := range stmt.Ledger {
 		fv.Ledger = append(fv.Ledger, adminconsole.LedgerRow{
 			Kind: e.Kind, Source: e.Source, Origin: e.Origin, ChipsDelta: e.ChipsDelta,
-			Product: e.ProductID, Order: e.OrderID, Provider: e.Provider, Snapshot: e.Snapshot,
+			Product: e.ProductID, Order: e.OrderID, Provider: e.Provider, Shop: e.Shop, Snapshot: e.Snapshot,
 			At: fmtTime(e.CreatedAt),
 		})
 	}
 	return fv
 }
 
+// overrideName renders a purchase override as the form/select value ("default"/"allow"/"deny").
+func overrideName(ov payments.PurchaseOverride) string {
+	switch ov {
+	case payments.OverrideAllow:
+		return "allow"
+	case payments.OverrideDeny:
+		return "deny"
+	default:
+		return "default"
+	}
+}
+
+// consoleSetPurchaseOverride sets or clears an account's per-account purchase override (allow / deny
+// / default) from the user card. "allow" bypasses only the operational rail switch, never the
+// security gates; "default" clears the override (deletes the row).
+func (s *Server) consoleSetPurchaseOverride(c *gin.Context) {
+	id, ok := s.consoleUUID(c, "/_gm/users")
+	if !ok {
+		return
+	}
+	back := "/_gm/users/" + id.String()
+	if s.payments == nil {
+		s.renderConsoleMessage(c, "Unavailable", "payments are not configured", back)
+		return
+	}
+	var ov payments.PurchaseOverride
+	switch c.PostForm("override") {
+	case "allow":
+		ov = payments.OverrideAllow
+	case "deny":
+		ov = payments.OverrideDeny
+	default:
+		ov = payments.OverrideDefault
+	}
+	if err := s.payments.SetPurchaseOverride(c.Request.Context(), id, ov); err != nil {
+		s.renderConsoleMessage(c, "Update failed", err.Error(), back)
+		return
+	}
+	s.renderConsoleMessage(c, "Saved", "the purchase override was updated", back)
+}
+
 // relationRows maps the social graph entries to the cross-linked, date-formatted rows the
 // user card renders.
 func relationRows(rels []social.AdminRelation) []adminconsole.RelationRow {

backend/internal/server/handlers_auth.go

@@ -160,16 +160,20 @@ type guestAuthRequest struct {
 	// Subtype is the client-reported device family (ios/android/web) of this direct
 	// (web/native) session; there is no external signer, so it is recorded best-effort.
 	Subtype string `json:"subtype"`
+	// Language is the client's detected interface locale, seeding the fresh guest's
+	// interface language (best-effort; an unsupported/absent value keeps the 'en' default).
+	Language string `json:"language"`
 }
 
 // handleGuestAuth provisions a fresh ephemeral guest account and mints a session,
-// seeding its time zone from the optional detected browser offset.
+// seeding its time zone from the optional detected browser offset and its interface
+// language from the optional detected locale.
 func (s *Server) handleGuestAuth(c *gin.Context) {
-	// The body is optional: an absent or malformed one simply yields no time-zone seed
+	// The body is optional: an absent or malformed one simply yields no time-zone/language seed
-	// (the account keeps the UTC default), so a bind error must not fail the bootstrap.
+	// (the account keeps the UTC / 'en' defaults), so a bind error must not fail the bootstrap.
 	var req guestAuthRequest
 	_ = c.ShouldBindJSON(&req)
-	acc, err := s.accounts.ProvisionGuest(c.Request.Context(), req.BrowserTZ)
+	acc, err := s.accounts.ProvisionGuest(c.Request.Context(), req.BrowserTZ, req.Language)
 	if err != nil {
 		s.abortErr(c, err)
 		return

backend/internal/server/handlers_intake.go

@@ -12,6 +12,7 @@ import (
 	"go.uber.org/zap"
 
 	"scrabble/backend/internal/payments"
+	"scrabble/backend/internal/robokassa"
 )
 
 // Ledger/order provider tags per rail.
@@ -66,9 +67,25 @@ func (s *Server) handleWalletOrder(c *gin.Context) {
 		s.abortErr(c, err)
 		return
 	}
+	// Operational availability gate (D45/D46): the per-rail kill switch + the per-account override,
+	// before any order is opened. Orthogonal to the security gates in the rail branches below — a
+	// per-account "allow" override bypasses only this switch, never those. The reason is localized to
+	// the account's language for the user.
+	lang := ""
+	if acc, aerr := s.accounts.GetByID(ctx, uid); aerr == nil {
+		lang = acc.PreferredLanguage
+	}
+	if ok, reason, aerr := s.payments.CanPurchase(ctx, uid, payments.RailKey(cxt.Kind, cxt.Subtype), lang); aerr != nil {
+		s.abortErr(c, aerr)
+		return
+	} else if !ok {
+		c.AbortWithStatusJSON(http.StatusServiceUnavailable, errorResponse{Error: errorBody{Code: "payment_unavailable", Message: reason}})
+		return
+	}
 	switch cxt.Kind {
 	case payments.SourceDirect:
-		if s.robokassa.MerchantLogin == "" {
+		shop, ok := s.robokassa.Shop(cxt.Subtype)
+		if !ok {
 			c.AbortWithStatusJSON(http.StatusNotImplemented, errorResponse{Error: errorBody{Code: "rail_unavailable", Message: "this payment method is not available"}})
 			return
 		}
@@ -89,7 +106,7 @@ func (s *Server) handleWalletOrder(c *gin.Context) {
 		}
 		c.JSON(http.StatusOK, walletOrderResponse{
 			OrderID:     res.OrderID.String(),
-			RedirectURL: s.robokassa.PaymentURL(res.OrderID, res.Amount.Major(), res.Title),
+			RedirectURL: shop.PaymentURL(res.OrderID, res.Amount.Major(), res.Title),
 			Rail:        providerRobokassa,
 		})
 	case payments.SourceVK:
@@ -136,7 +153,16 @@ func (s *Server) handleRobokassaResult(c *gin.Context) {
 	for k, val := range params {
 		v.Set(k, val)
 	}
-	orderID, outSum, ok := s.robokassa.VerifyResult(v)
+	// The per-shop Result route carries the channel as ?channel=; the legacy bare route defaults to
+	// the web shop. Each channel is verified only by its own shop's Password2 (Verifier is strict).
+	channel := c.DefaultQuery("channel", robokassa.ChannelWeb)
+	shop, ok := s.robokassa.Verifier(channel)
+	if !ok {
+		s.log.Warn("robokassa result: unknown shop channel", zap.String("channel", channel))
+		c.String(http.StatusBadRequest, "bad sign")
+		return
+	}
+	orderID, outSum, ok := shop.VerifyResult(v)
 	if !ok {
 		s.log.Warn("robokassa result: bad signature")
 		c.String(http.StatusBadRequest, "bad sign")

backend/internal/server/handlers_link.go

@@ -285,6 +285,12 @@ func (s *Server) handleLinkVKMerge(c *gin.Context) {
 // or a completed link (the active account's refreshed profile).
 func (s *Server) confirmResultResponse(c *gin.Context, activeID uuid.UUID, res link.ConfirmResult) linkResultResponse {
 	ctx := c.Request.Context()
+	if res.Merged {
+		// A guest initiator's merge ran inline (the guest-primary rule; no confirmation step),
+		// so render the completed merge — the client adopts the switched session and lands on
+		// the surviving durable account as if it simply logged in.
+		return s.mergeResultResponse(c, res.Merge)
+	}
 	if res.MergeRequired {
 		out := linkResultResponse{Status: "merge_required", SecondaryUserID: res.SecondaryID.String()}
 		if acc, err := s.accounts.GetByID(ctx, res.SecondaryID); err == nil {

backend/internal/server/server.go

@@ -115,9 +115,9 @@ type Deps struct {
 	// Renderer is the image-render sidecar client for the PNG export artifact. A
 	// nil Renderer makes the PNG download answer 404 (the GCG artifact still works).
 	Renderer *render.Client
-	// Robokassa configures the direct-rail (RUB) provider; an empty MerchantLogin leaves the
+	// Robokassa configures the direct-rail (RUB) provider — one merchant shop per channel; an empty
-	// order and Result-callback endpoints unregistered.
+	// set leaves the order and Result-callback endpoints unregistered.
-	Robokassa robokassa.Config
+	Robokassa robokassa.Shops
 }
 
 // Server owns the gin engine, the underlying HTTP server and the readiness
@@ -146,7 +146,7 @@ type Server struct {
 	ads         *ads.Service
 	payments    *payments.Service
 	gamelimits  *gamelimits.Service
-	robokassa   robokassa.Config
+	robokassa   robokassa.Shops
 	notifier    notify.Publisher
 	console     *adminconsole.Renderer
 	exportKey   []byte

backend/internal/telemetry/middleware.go

@@ -56,6 +56,9 @@ func Middleware(logger *zap.Logger) gin.HandlerFunc {
 			zap.String("path", route),
 			zap.Int("status", status),
 			zap.Duration("latency", elapsed),
+			// The gateway forwards the real caller as X-Forwarded-For (and Caddy does for /_gm), which
+			// gin resolves here — so the access log carries the client IP, not the gateway's connection.
+			zap.String("client_ip", c.ClientIP()),
 		}
 		fields = append(fields, TraceFieldsFromContext(ctx)...)
 

deploy/.env.example

@@ -142,6 +142,18 @@ ROBOKASSA_MERCHANT_LOGIN=
 ROBOKASSA_PASSWORD1=
 ROBOKASSA_PASSWORD2=
 ROBOKASSA_TEST=
+# Multi-shop direct rail (D42): the vars above seed the "web" channel; add per-channel shops here.
+# ROBOKASSA_WEB_* overrides the web shop; ROBOKASSA_ANDROID_* adds the android (RuStore) shop. Each
+# credits the one direct wallet; an empty login drops that channel (routing falls back to web). The
+# Robokassa cabinet points each shop's Result URL at /pay/robokassa/result/web and .../android.
+ROBOKASSA_WEB_MERCHANT_LOGIN=
+ROBOKASSA_WEB_PASSWORD1=
+ROBOKASSA_WEB_PASSWORD2=
+ROBOKASSA_WEB_TEST=
+ROBOKASSA_ANDROID_MERCHANT_LOGIN=
+ROBOKASSA_ANDROID_PASSWORD1=
+ROBOKASSA_ANDROID_PASSWORD2=
+ROBOKASSA_ANDROID_TEST=
 
 # --- Gateway anti-abuse ------------------------------------------------------
 # Planted honeytoken bearer value: any request presenting it is flagged — a 24h IP ban

deploy/README.md

@@ -79,6 +79,7 @@ compose binds from this directory.
 | `BACKEND_ROBOKASSA_MERCHANT_LOGIN` | secret | Robokassa shop login for the direct RUB rail. Empty leaves the rail off. |
 | `BACKEND_ROBOKASSA_PASSWORD1` / `…_PASSWORD2` | secret | Robokassa pass phrases: Password1 signs the launch request, Password2 signs/verifies the Result callback. Use the shop's **test** pair while `…_ROBOKASSA_TEST=1`, the **live** pair for real money. (Password3 — Robokassa's JWT-invoice API — is unused.) |
 | `BACKEND_ROBOKASSA_TEST` | **variable** | `1` runs test payments against the test pass phrases (no real money); empty/`0` is live. A variable, not a secret, so go-live is a flag flip + redeploy, not a secret rotation. |
+| `BACKEND_ROBOKASSA_{WEB,ANDROID}_{MERCHANT_LOGIN,PASSWORD1,PASSWORD2,TEST}` | secret / variable | Multi-shop direct rail (D42): per-channel Robokassa shops. The legacy `BACKEND_ROBOKASSA_*` seeds the **web** shop; `…_WEB_*` overrides it, `…_ANDROID_*` adds the **android** (RuStore) shop. Each credits the one `direct` wallet; the cabinet Result URL per shop is `/pay/robokassa/result/{web,android}`. Empty login ⇒ that channel unconfigured (order routing falls back to the web shop). |
 
 **Plus the bot token** — `TELEGRAM_BOT_TOKEN` (secret), shared by the validator (HMAC
 secret) and the bot (Bot API). It defaults to empty in compose, but both **fail at
@@ -97,7 +98,7 @@ without it Docker's resolver handles `otelcol`, `gateway` and `api.telegram.org`
 | --- | --- | --- | --- |
 | `POSTGRES_DB` | variable | `scrabble` | Database name. |
 | `POSTGRES_USER` | variable | `scrabble` | Database user. |
-| `DICT_VERSION` | variable (shared) | `v1.3.1` | `scrabble-dictionary` release tag baked into the backend image as the **seed for a fresh volume** (build-arg). A live contour changes dictionary through the admin console, not this; on a seeded volume a changed value is ignored (the recorded `.seed_version` marker wins — the seed-drift guard, ARCHITECTURE.md §5). One shared unprefixed Gitea variable seeds both contours and pins the CI test suite. |
+| `DICT_VERSION` | variable (shared) | `v1.3.1` | `scrabble-dictionary` release tag baked into the backend image (build-arg). **Deploy-authoritative**: a redeploy that bumped it **delivers** the version onto the volume (add-only) and **activates** it for new games — old games keep the version they pin, and a newer out-of-band console upload is never downgraded (ARCHITECTURE.md §5). The `.seed_version` marker still guards the flat seed's label (a bump is delivered as a new subdirectory, never a relabel). One shared unprefixed Gitea variable seeds both contours and pins the CI test suite. |
 | `LOG_LEVEL` | variable | `info` | Shared log level for backend / gateway / validator / bot (`debug\|info\|warn\|error`). |
 | `CADDY_SITE_ADDRESS` | variable | `:80` | Caddy site address. Test: `:80` (host caddy terminates TLS). Prod: a domain, so caddy does its own ACME. |
 | `GM_BASICAUTH_USER` | variable | `gm` | Username for the `/_gm` Basic-Auth. |
@@ -175,10 +176,14 @@ For local builds set `DICT_VERSION` in `deploy/.env` (template: `.env.example`);
 `docker build` needs `--build-arg DICT_VERSION=vX.Y.Z`. The Dockerfiles and `compose` carry no
 default — a missing value fails loudly instead of baking a stale tag.
 
-Bumping the seed is a **no-op on a live volume** (the `.seed_version` marker wins — the
+Bumping `DICT_VERSION` and **redeploying** takes a live contour/prod to the new dictionary:
-seed-drift guard). A running contour/prod moves to a new release **through the admin console**
+on boot the backend **delivers** the build's version onto the volume (add-only, into
-`/_gm/dictionary` (upload the tarball, preview the per-variant diff, confirm); in-flight games
+`BACKEND_DICT_DIR/<version>/` from the unshadowed `BACKEND_DICT_SEED_DIR`) and **activates** it,
-keep their pinned version, new games use the new one (ARCHITECTURE.md §5).
+so new games pin it while in-flight games keep the version they started on. The `.seed_version`
+marker still guards the flat seed's label (the delivery is a new subdirectory, never a relabel).
+The admin console `/_gm/dictionary` (upload the tarball, preview the per-variant diff, confirm)
+remains for an **out-of-band** update without a redeploy; a console version newer than the build
+survives a later restart on an older image (ARCHITECTURE.md §5).
 
 ## Production rollout
 
@@ -256,8 +261,8 @@ web/prod rollout — a signed APK uploaded to RuStore by hand. The build/release
   the SDK is missing or unreadable.
 - **Release keystore** (create once, **back up off-host** — losing it means the app can never be updated):
   `keytool -genkeypair -v -keystore erudit-release.jks -alias erudit -keyalg RSA -keysize 4096 -validity 10000`,
-  then set the Gitea **secrets** `ANDROID_KEYSTORE_BASE64` (`base64 -w0 erudit-release.jks`),
+  then set the Gitea **secrets** `ANDROID_RUSTORE_KEYSTORE_BASE64` (`base64 -w0 erudit-release.jks`),
-  `ANDROID_KEYSTORE_PASSWORD`, `ANDROID_KEY_ALIAS`, `ANDROID_KEY_PASSWORD`. Set the `ANDROID_RUSTORE_URL`
+  `ANDROID_RUSTORE_KEYSTORE_PASSWORD`, `ANDROID_RUSTORE_KEY_ALIAS`, `ANDROID_RUSTORE_KEY_PASSWORD`. Set the `ANDROID_RUSTORE_URL`
   variable to the store listing once published (empty until then — the in-app update button no-ops).
 - **Wire-break discipline:** the prod deploy that ships an incompatible wire change **also** bumps
   `GATEWAY_MIN_CLIENT_VERSION` to that release (see Optional variables), so an old installed APK is turned

deploy/ansible/roles/common/tasks/main.yml

@@ -150,6 +150,13 @@
     enabled: true
     state: started
 
+# Pin every host to UTC so host-level timestamps (journald, file mtimes, cron) line up
+# across the fleet — some VPS images ship a local zone (the tg host came up on MSK). The
+# services themselves run in UTC regardless; this is about host-side log correlation.
+- name: Set the system timezone to UTC
+  community.general.timezone:
+    name: Etc/UTC
+
 # --- Swap file (OOM cushion) ---------------------------------------------------
 # The prod main host is tight (1.9 GiB) and the per-container memory caps
 # (docker-compose.prod.yml) sum to more than RAM, so a simultaneous spike could hit

deploy/docker-compose.yml

@@ -171,6 +171,18 @@ services:
       BACKEND_ROBOKASSA_PASSWORD1: ${ROBOKASSA_PASSWORD1:-}
       BACKEND_ROBOKASSA_PASSWORD2: ${ROBOKASSA_PASSWORD2:-}
       BACKEND_ROBOKASSA_TEST: ${ROBOKASSA_TEST:-}
+      # Per-channel shops for the multi-shop direct rail (D42): the legacy ROBOKASSA_* above seeds
+      # the "web" channel; ROBOKASSA_WEB_* overrides it and ROBOKASSA_ANDROID_* adds the android
+      # shop. Each shop credits the one direct wallet; an empty login drops that channel (order
+      # routing falls back to the web shop). Result URLs: /pay/robokassa/result/{web,android}.
+      BACKEND_ROBOKASSA_WEB_MERCHANT_LOGIN: ${ROBOKASSA_WEB_MERCHANT_LOGIN:-}
+      BACKEND_ROBOKASSA_WEB_PASSWORD1: ${ROBOKASSA_WEB_PASSWORD1:-}
+      BACKEND_ROBOKASSA_WEB_PASSWORD2: ${ROBOKASSA_WEB_PASSWORD2:-}
+      BACKEND_ROBOKASSA_WEB_TEST: ${ROBOKASSA_WEB_TEST:-}
+      BACKEND_ROBOKASSA_ANDROID_MERCHANT_LOGIN: ${ROBOKASSA_ANDROID_MERCHANT_LOGIN:-}
+      BACKEND_ROBOKASSA_ANDROID_PASSWORD1: ${ROBOKASSA_ANDROID_PASSWORD1:-}
+      BACKEND_ROBOKASSA_ANDROID_PASSWORD2: ${ROBOKASSA_ANDROID_PASSWORD2:-}
+      BACKEND_ROBOKASSA_ANDROID_TEST: ${ROBOKASSA_ANDROID_TEST:-}
     # The dictionary lives on a named volume seeded from the image on first boot
     # (the image's /opt/dawg is owned by the nonroot UID, which the fresh volume
     # inherits). The admin console writes new version subdirectories here, and the

docs/ARCHITECTURE.md

@@ -151,7 +151,10 @@ dropped). Horizontal scaling is explicit future work.
   and GCG are unaffected** (they stay decoded concrete characters, §9.1).
 - **gateway ↔ backend (sync)**: plain HTTP REST/JSON. The gateway injects
   `X-User-ID` (and the session's trusted `X-Platform`, §3) for authenticated
-  requests; `backend` never re-derives identity or platform from the body. Because every sync call targets the one backend host, the
+  requests, plus the caller's real IP as **`X-Forwarded-For`** on **every** call
+  (carried on the request context), so the backend records the real caller — the
+  account's last-login IP, chat/feedback moderation, the access log — rather than
+  the gateway's own connection address; `backend` never re-derives identity or platform from the body. Because every sync call targets the one backend host, the
   gateway's REST client widens its keep-alive pool well past the stdlib default
   of 2 idle connections per host; otherwise the per-request connection churn
   exhausts ephemeral ports and burns gateway CPU under load (see
@@ -443,22 +446,27 @@ Key points:
   version while new games use the new one. A restart re-loads every resident
   version via `engine.OpenWithVersions` (the flat seed plus each subdirectory,
   skipping the `.staging/` upload area) and restores the active pointer from
-  `dictionary_state`. The volume preserves uploaded versions across redeploys;
+  `dictionary_state`. The volume preserves uploaded versions across redeploys, so
-  once seeded it is not re-seeded, so after bootstrap dictionary changes go through
+  in-flight games keep replaying on the version they pin. The build's
-  the console rather than a rebuild. Because the flat DAWGs carry no embedded
+  `BACKEND_DICT_VERSION` is **deploy-authoritative**: on boot `engine.DeliverVersion`
-  version, `OpenWithVersions` records the version the flat directory was first seeded
+  copies the image's DAWGs — kept unshadowed at `BACKEND_DICT_SEED_DIR`, since the
-  at in a `.seed_version` marker on the volume and treats that marker as
+  volume mount hides the image's `BACKEND_DICT_DIR` copy — into
-  **authoritative** (the **seed-drift guard**): on an already-seeded volume a later
+  `BACKEND_DICT_DIR/<version>/` when that version is not already resident (**add-only**:
-  `BACKEND_DICT_VERSION` is ignored, so a bumped build seed cannot relabel the
+  the flat seed and prior uploads are never touched), and `InitActiveVersion` makes it
-  already-seeded bytes — which would otherwise silently serve the wrong dictionary
+  the active version. So a redeploy that bumped `DICT_VERSION` moves new games to the
-  and void games pinned to the prior label. A running contour therefore moves to a
+  new dictionary automatically, while old games stay on theirs — no console step. The
-  new release **through the console** (the prior version stays resident, so its games
+  one exception: a version installed out-of-band through the console that is **newer**
-  keep replaying), and `DICT_VERSION` is the seed for a **fresh** volume only:
+  than the build version and still resident is kept, so a restart on an older image never
-  bumping it on a live contour is a harmless no-op that takes effect on the next
+  downgrades a hotfix (versions compare numerically). Because the flat DAWGs carry no
-  fresh volume. Set it per contour from the deploy's `TEST_`/`PROD_DICT_VERSION`.
+  embedded version, `OpenWithVersions` records the version the flat directory was first
-  (The dictionaries ship as a versioned **release artifact** from the
+  seeded at in a `.seed_version` marker and treats it as authoritative for **that flat
-  `scrabble-dictionary` repo; the build's `DICT_VERSION` selects
+  directory** (the **seed-drift guard**): a later `BACKEND_DICT_VERSION` never relabels
-  only the seed.)
+  the already-seeded flat bytes — it is delivered as a **new subdirectory** instead — so
+  the guard still prevents mis-serving a game pinned to the flat label. The console
+  remains the way to update a dictionary **without** a redeploy (an out-of-band upload).
+  Set `DICT_VERSION` per contour from the deploy's `TEST_`/`PROD_DICT_VERSION`. (The
+  dictionaries ship as a versioned **release artifact** from the `scrabble-dictionary`
+  repo.)
 - Move generation/validation/scoring use `Solver.GenerateMoves` (ranked),
   `Solver.ValidatePlay` and `Solver.ScorePlay`; board mutation uses
   `scrabble.Apply`. The engine adds its own deterministic, seeded tile **bag**
@@ -1496,7 +1504,8 @@ Two contours, two secret/variable prefixes (`TEST_` / `PROD_`):
   forwards the domain to `scrabble:80`, so the in-compose caddy serves plain HTTP
   (`CADDY_SITE_ADDRESS=:80`). The in-compose caddy **trusts X-Forwarded-For from
   private-range upstreams** (`trusted_proxies private_ranges`), so the real client IP —
-  used for chat-moderation logging and the gateway's per-IP rate limiting — survives the
+  used for the gateway's per-IP rate limiting and, forwarded on to the backend, the account's
+  last-login IP, chat/feedback moderation and the access log — survives the
   host-caddy hop; in prod (no host caddy) public clients are untrusted and Caddy uses the
   real peer, so the single config is correct and spoof-safe in both contours. The
   **bot-link mTLS material** (a private CA + gateway/bot leaves, CN=`gateway`) is

docs/FUNCTIONAL.md

@@ -50,7 +50,7 @@ tail — at a real control, and a **tap anywhere** advances to the next; after t
 overlay is gone for good. Two independent series run. The **lobby** series points at the
 ⚙️ settings, ✏️ statistics and 🎲 new-game tabs. The **game** series, on the player's first game
 board, points at the scoreboard header (move history / chat / word-check), the 🔄 pass-and-exchange,
-🛟 hints and 🔀 shuffle controls, and the rack. A series counts as seen only **after its last hint**,
+✨ hints and 🔀 shuffle controls, and the rack. A series counts as seen only **after its last hint**,
 so leaving mid-way replays it from the start next time; it is remembered per device. Arriving at the
 lobby is the lobby trigger, so a player who deep-links straight into Settings → Friends still gets the
 lobby walk-through on their first trip back. Both series work the same in portrait and landscape (the
@@ -117,12 +117,15 @@ First platform contact auto-provisions a durable account. From the profile a pla
 links an email (via a confirm code) or their Telegram (via the web sign-in); a guest
 who links their first identity becomes a durable account. The "already taken" status
 of an identity is never revealed before the code/sign-in is verified. If the linked
-identity already belongs to another account, the player is shown an explicit,
+identity already belongs to another account, the two accounts are merged into one
-**irreversible** confirmation and the two accounts are merged into the one they are
+(statistics summed, games and friends transferred, wallet folded, duplicates removed).
-using (statistics summed, games and friends transferred, duplicates removed) — except
+A **durable** initiator is shown an explicit, **irreversible** confirmation first —
-when a guest links an identity that already has a durable account, where the durable
+consolidating two real accounts is consequential. A **guest** initiator is not: the
-account is kept and the guest's games move into it. A merge is blocked only while the
+durable account that owns the identity is kept, and the ephemeral guest — with its games,
-two accounts share a game still in progress.
+wallet and stats folded in — is retired **seamlessly**, so from the player's side it is
+simply signing into their account (the app switches to it with no prompt). A merge is
+blocked only while the two accounts share a game still in progress; a guest is then asked
+to finish that shared game before signing in.
 
 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

docs/FUNCTIONAL_ru.md

@@ -52,7 +52,7 @@ Telegram-бот, который документы указывают как к
 следующей; после последней подсказки оверлей убирается навсегда. Серий две. Серия **лобби**
 указывает на вкладки ⚙️ настроек, ✏️ статистики и 🎲 новой игры. Серия **игры**, на первой партии
 игрока, указывает на шапку со счётом (история ходов / чат / проверка слова), кнопки 🔄 пас-и-обмен,
-🛟 подсказок и 🔀 перемешивания, и на стойку с фишками. Серия считается просмотренной только
+✨ подсказок и 🔀 перемешивания, и на стойку с фишками. Серия считается просмотренной только
 **после последней подсказки**, поэтому выход на середине в следующий раз покажет её с начала;
 запоминается она по устройству. Триггер серии лобби — попадание в лобби, так что игрок, пришедший
 по deeplink сразу в Настройки → Друзья, всё равно получит проводку по лобби при первом возврате.
@@ -121,12 +121,14 @@ Telegram держит **единого бота**: все игроки поль
 привязывает email (по confirm-коду) или свой Telegram (через веб-вход); гость,
 привязавший первую личность, становится постоянным аккаунтом. Факт «личность уже
 занята» не раскрывается до проверки кода/входа. Если привязываемая личность уже
-принадлежит другому аккаунту, игроку показывают явное **необратимое**
+принадлежит другому аккаунту, два аккаунта сливаются в один (статистика суммируется,
-подтверждение, и два аккаунта сливаются в тот, под которым он сейчас работает
+игры и друзья переносятся, кошелёк складывается, дубликаты убираются). **Постоянному**
-(статистика суммируется, игры и друзья переносятся, дубликаты убираются), — кроме
+инициатору сначала показывают явное **необратимое** подтверждение — объединение двух
-случая, когда гость привязывает личность с уже существующим постоянным аккаунтом:
+настоящих аккаунтов важно. **Гостю** — нет: сохраняется постоянный аккаунт-владелец
-тогда сохраняется постоянный аккаунт, а игры гостя переходят в него. Слияние
+личности, а эфемерный гость (с его играми, кошельком и статистикой) ретайрится
-запрещено, только пока у аккаунтов есть общая незавершённая игра.
+**бесшовно**, так что со стороны игрока это просто вход в свой аккаунт (приложение
+переключается на него без запроса). Слияние запрещено, только пока у аккаунтов есть
+общая незавершённая игра; гостя тогда просят сперва доиграть эту общую партию.
 
 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

docs/ICONS.md

@@ -54,7 +54,10 @@ already fill the 108 dp canvas (foreground inside the 61 % safe zone, background
 full-bleed), so they must be placed with **no inset**, and we add the **monochrome**
 themed layer, neither of which `capacitor-assets` does. Per density mdpi→xxxhdpi (+ldpi):
 
-- `mipmap-*/ic_launcher.png` / `ic_launcher_round.png` — legacy square / round (composite)
+- `mipmap-*/ic_launcher.png` — legacy square (< API 26): the **full-bleed master** (large
+  mark), so old square launchers do not shrink it into the safe zone
+- `mipmap-*/ic_launcher_round.png` — legacy round (< API 26): the safe-zone **composite**,
+  circle-clipped (a round mask would clip the master's corner ✻)
 - `mipmap-*/ic_launcher_foreground.png` + `ic_launcher_background.png` — adaptive layers
 - `mipmap-*/ic_launcher_monochrome.png` — themed layer
 - `mipmap-anydpi-v26/ic_launcher.xml` + `ic_launcher_round.xml` — **no `<inset>`**, with

docs/ICON_BRANDBOOK.md

@@ -123,12 +123,13 @@ So Android is **not** the full-bleed master — it is built as two layers:
   and square** (no rounded corners; the OS supplies the shape). It fills the whole 108 dp
   layer, so the sacrificial outer ring is just more wood.
 - **Foreground** — **only the «Э» + ✻**, transparent, **re-placed** to sit safely inside
-  the mask:
+  the mask. The whole mark is the master's optical placement (nudged right 8 % / down 3 %)
-  - «Э»: box height **53.9 %**, box center **52.3 % / 49.5 %**.
+  scaled **0.75 about the icon centre** — **25 % smaller**, its «Э» ↔ ✻ arrangement
-  - ✻: outer diameter **13.2 %** (smaller than the master's), center **76.3 % / 72.7 %**,
+  unchanged — so the ✻ that used to graze the round mask now sits well inside the **61 %
+  safe zone** with margin to spare:
+  - «Э»: box height **40.4 %**, box center **51.8 % / 49.6 %**.
+  - ✻: outer diameter **9.9 %** (smaller than the master's), center **69.7 % / 67.0 %**,
     tucked closer to the letter.
-  - The mark is centred, then nudged **right 8 % / down 3 %** so it reads optically
-    centred under the round mask, and the whole group fits within the **61 % safe zone**.
 
 Everything else (palette, grain, gradients, star construction) is identical to the master.
 

docs/PAYMENTS.md

@@ -57,6 +57,21 @@ for outside the store's own cash desk. Chips funded inside VK (Votes) may only b
 the VK context; Stars only inside Telegram; Robokassa-funded (`direct`) chips only outside
 the stores. See §4.
 
+**Multi-shop direct rail (D42).** The `direct` rail routes to one Robokassa **merchant shop per
+channel** — `web` and `android` (RuStore), `ios` later — chosen by the trusted `X-Platform` subtype;
+every shop credits the one `direct` wallet (no per-channel wallet). This is merchant-account
+separation for accounting / receipts only: the order records its `shop` (shown in the admin report),
+and each shop's Result callback is verified by its own Password2 at `/pay/robokassa/result/<channel>`.
+Standalone apps (Android/iOS) sign in by email only, so a direct purchase always has the D36 email
+anchor (D43). Fiscalization (54-ФЗ via the Robokassa cabinet under one ИП) is a single source
+regardless of the number of shops (D41).
+
+**Payment availability kill switch (D45/D46).** An operator can disable purchases on a rail/channel
+(`direct:web` / `direct:android` / `vk` / `telegram`) or for one account, live from `/_gm`, and the
+user sees a localized reason on their next attempt (`payment_unavailable`, carried on the additive
+`ExecuteResponse.message`). **Fail-open:** a rail with no status row is enabled. A per-account
+`allow` override bypasses only this operational switch, never the security gates (D46).
+
 ## 3. Three operations, kept distinct
 
 Do not conflate these — they use different keys:

docs/PAYMENTS_DECISIONS_ru.md

@@ -234,11 +234,53 @@ web+PWA / native Android+iOS через Capacitor). Владелец (самоз
 - **D40. Финансовый отчёт per-user в `/_gm`** — балансы сегментов, платежи, траты,
   гранты, возвраты, полная история — расширение существующей карточки
   (`UserDetailView`, `handlers_admin_console.go:343`). Плюс экспорт журнала (D27).
-- **D41. Налоги/чеки — авто через провайдера.** **Robokassa** (direct) — авточек НПД
+- **D41. Налоги/чеки — авто через провайдера (ревизия: владелец переходит на ИП).**
-  (режим самозанятого). **VK** — сам процессит Голоса через налоговую (владельцу делать
+  **Robokassa** (direct) — фискальный чек по **54-ФЗ** через облачную кассу Robokassa
-  нечего). **TG Stars** — налоговой стороны нет (для РФ-самозанятого невыводимы легально
+  (провайдер как фискальный агент): чек формирует касса, не банк (банковский слип об оплате —
-  = не доход по НПД; принимаем, чек не формируем). ОРД по VK-рекламе — на стороне VK.
+  отдельный документ, не фискальный чек). Настраивается владельцем в ЛКК Robokassa
-  *(Не юридическая консультация — точную схему НПД владелец сверяет с налоговой стороной.)*
+  (касса + ОФД + СНО). Код — опционально: слать детализированный `Receipt` + `Email`
+  покупателя (берём подтверждённый email-якорь D36) → чек с точным названием пакета и ставкой
+  по СНО; иначе — обобщённый дефолт-чек из кабинета. `Receipt` входит в подпись
+  (`MerchantLogin:OutSum:InvId:Receipt:Пароль#1`, URL-кодируется), одна позиция влезает в
+  текущий GET-redirect (POST-форма — фолбэк на длину URL). Источник чеков один — ИП/касса,
+  независимо от числа магазинов Robokassa. **VK** — процессит Голоса через налоговую сам.
+  **TG Stars** — вне рублёвого фискального контура (принимаем, чек не формируем). ОРД по
+  VK-рекламе — на стороне VK. *(Не юрконсультация — схему по 54-ФЗ/СНО владелец сверяет с
+  бухгалтером.)*
+- **D42. Direct-рельс — несколько магазинов Robokassa = маршрутизация merchant-аккаунтов по
+  каналу при едином кошельке.** Кошелёк `direct` остаётся один. Отдельные магазины Robokassa
+  (web, android; ios — позже) различаются только кредами / Return-URL / учётом и **все
+  зачисляют в сегмент `direct`**. Модель кошельков, стенка трат и origin бенефитов не меняются.
+  Магазин выбирается по трастовому сигналу канала (`X-Platform` вида `<kind>/<subtype>`:
+  `direct/web`, `direct/android`), а не по подделываемому клиентскому полю; неизвестный подтип
+  → магазин `web` (безопасный дефолт). Зачисление от выбора магазина не зависит (всегда
+  `direct`), поэтому ошибка маршрутизации влияет максимум на учёт, не на деньги.
+- **D43. Standalone-приложения (Android, iOS) — вход только по email; покупка требует
+  email-якорь.** В нативной сборке доступны только guest + email: VK ID-логин (full-page
+  redirect на `id.vk.com`) не возвращается в Capacitor, TG Login Widget в WebView ненадёжен —
+  это уже действующая реальность сборки, не новое ограничение. Direct-покупка требует
+  подтверждённого email-якоря (D36) — он же адрес фискального чека (D41); гость не покупает.
+  Отдельный сегмент `apple` НЕ заводим: iOS-standalone — тот же `direct`-контекст, внешний гейт
+  (Robokassa) фондирует единый `direct`. Сегмент `apple` со стенкой (по образцу vk/tg)
+  понадобился бы только при Apple IAP (StoreKit) — отложено до решения по iOS; и identity-kind
+  `apple→direct`, и отдельный сегмент — аддитивны, без риска, делаются на месте.
+- **D44. Канал платежа хранится на заказе для раздельного учёта/отчёта.** Заказ получает поле
+  `shop` (web/android/…) — аддитивная колонка. Используется в финансовом отчёте (D40) для
+  разбивки «из какого магазина/канала платёж». На зачисление и на сегмент кошелька не влияет
+  (всегда `direct`, D42).
+- **D45. Рубильник платежей per-rail + локализованное сообщение.** Оператор выключает покупки на
+  рельсе/канале (`direct:web`/`direct:android`/`vk`/`telegram`) живьём из `/_gm` (таблица
+  `payments.rail_status`, редактируется на странице каталога). **Fail-open:** нет строки → рельс
+  включён (случайно не убить платежи). Выключенный рельс на попытке покупки возвращает
+  `payment_unavailable` + сообщение админа на языке юзера (RU/EN; пусто → встроенное «временно
+  недоступно»). Сообщение едет клиенту через аддитивное `ExecuteResponse.message` (envelope-слой,
+  frozen-contract-safe). Гейт ортогонален security-гейтам.
+- **D46. Per-user override покупок (allow/deny/default).** На карточке юзера (`/_gm`) —
+  переопределение на аккаунт: `allow` (всегда разрешить), `deny` (всегда запретить), `default` (по
+  рельс-рубильнику). Хранится в `payments.account_payment_override` строкой только для не-default
+  (нет строки = default; снять = удалить строку). **`allow` обходит ТОЛЬКО ops-рубильник, НЕ
+  security-гейты** (D36 email-якорь, VK-iOS-фриз, trusted-платформа, min-client-version) — те
+  проверяются отдельно в CreateOrder.
 
 ## Заметки к оформлению документов
 
@@ -254,10 +296,17 @@ web+PWA / native Android+iOS через Capacitor). Владелец (самоз
   ведёт к пропускам. Текст — только для фиксации решённого и пояснений. Усилить
   feedback-память `prefer-interview-mode` после plan mode.
 
-## Все развилки закрыты (D1-D41)
+## Все развилки закрыты (D1-D46)
 
 Интервью завершено. Дальше — оформление документов и реализация по релизам.
 
+**Дополнение 2026-07-14 (интервью с владельцем).** D41 ревизована (владелец переходит на
+ИП: 54-ФЗ через облачную кассу Robokassa вместо авточека НПД); добавлены D42-D44 — сплит
+`direct`-рельса Robokassa на магазины по каналу (web/android; ios позже) при едином кошельке
+`direct` и входе email-only в standalone-приложениях (этап E10 в `PLAN.md`). Плюс D45-D46 —
+рубильник платежей per-rail + локализованное сообщение + per-user override (этап E11). Фискализация
+(B4) — кабинетная на стороне Robokassa, itemized-код не делаем (решение владельца).
+
 ## План внедрения (черновик PLAN.md — «слоями»)
 
 Владелец выбрал слоёную стратегию: сначала вся механика без реальных денег (обкатка

docs/PAYMENTS_ru.md

@@ -57,6 +57,21 @@
 в контексте VK; Stars — только внутри Telegram; Фишки от Robokassa (`direct`) — только вне
 сторов. См. §4.
 
+**Мультимагазинный direct-рельс (D42).** Рельс `direct` маршрутизирует в отдельный магазин
+Robokassa **на канал** — `web` и `android` (RuStore), позже `ios` — по трастовому подтипу
+`X-Platform`; каждый магазин зачисляет в единый кошелёк `direct` (отдельных кошельков на канал нет).
+Это разделение merchant-аккаунтов только для учёта / чеков: заказ хранит свой `shop` (виден в
+админ-отчёте), а Result-колбэк каждого магазина проверяется своим Password2 по
+`/pay/robokassa/result/<channel>`. В standalone-приложениях (Android/iOS) вход только по email, поэтому
+у direct-покупки всегда есть email-якорь D36 (D43). Фискализация (54-ФЗ через кабинет Robokassa под
+одним ИП) — один источник независимо от числа магазинов (D41).
+
+**Рубильник платежей (D45/D46).** Оператор выключает покупки на рельсе/канале (`direct:web` /
+`direct:android` / `vk` / `telegram`) или для одного аккаунта, живьём из `/_gm`, и юзер на следующей
+попытке видит локализованную причину (`payment_unavailable`, едет на аддитивном
+`ExecuteResponse.message`). **Fail-open:** рельс без строки статуса — включён. Per-account `allow`
+обходит только этот ops-рубильник, не security-гейты (D46).
+
 ## 3. Три операции, которые нельзя путать
 
 Не смешивать — у них разные ключи:

docs/UI_DESIGN.md

@@ -53,7 +53,7 @@ dismisses as soon as the lobby is ready. The pure layout and timing live in `lib
 
 A one-time **coachmark overlay** introduces the interface to a new player. Like the splash it is an
 **App-level overlay**; it runs two independent series chosen by the route — **lobby** (⚙️ settings →
-✏️ stats → 🎲 new game) and **game** (scoreboard header → 🔄 pass/exchange → 🛟 hints → 🔀 shuffle →
+✏️ stats → 🎲 new game) and **game** (scoreboard header → 🔄 pass/exchange → ✨ hints → 🔀 shuffle →
 rack). It draws **one bubble at a time** over a light scrim (`rgba(0,0,0,0.32)`); the whole layer
 captures pointer events, so a **tap anywhere advances** and the UI underneath stays inert. After the
 last hint the series is recorded done (`session.ts` `onboarding` key) and the overlay removes itself;
@@ -284,7 +284,7 @@ e2e and the screenshots.
   opens a dialog — pick tiles to **Exchange N**, or pick
   none to **Pass without exchanging**; pass is always available on your turn, exchange only
   while the bag still holds a full rack, below which the tiles disable and only the pass
-  remains), 🛟 Hint (with a remaining-count badge, disabled at zero); 🔀 Shuffle (no label,
+  remains), ✨ Hint (with a remaining-count badge, disabled at zero); 🔀 Shuffle (no label,
   no confirm), which
   **animates** — tiles hop along a low parabola to their new slots (duration scaled by the
   distance, the longest ≤ 0.3 s; off under reduce-motion) with a short haptic shake. A **thin strip

gateway/internal/backendclient/api.go

@@ -312,11 +312,12 @@ func (c *Client) ChatAccessByUser(ctx context.Context, userID string) (ChatAcces
 }
 
 // GuestAuth provisions a guest account and mints a session, seeding its time zone
-// from browserTz (the client's detected "±HH:MM" UTC offset).
+// from browserTz (the client's detected "±HH:MM" UTC offset) and its interface
-func (c *Client) GuestAuth(ctx context.Context, browserTz, subtype string) (SessionResp, error) {
+// language from language (the client's detected locale; best-effort).
+func (c *Client) GuestAuth(ctx context.Context, browserTz, subtype, language string) (SessionResp, error) {
 	var out SessionResp
 	err := c.do(ctx, http.MethodPost, "/api/v1/internal/sessions/guest", "", "",
-		map[string]string{"browser_tz": browserTz, "subtype": subtype}, &out)
+		map[string]string{"browser_tz": browserTz, "subtype": subtype, "language": language}, &out)
 	return out, err
 }
 
@@ -498,10 +499,15 @@ type robokassaResultResp struct {
 
 // RobokassaResult forwards a Robokassa Result callback's parameters to the backend intake (the
 // single writer, which verifies the signature and credits) and returns the body to echo to
-// Robokassa ("OK<InvId>"). params carries the provider's raw form fields.
+// Robokassa ("OK<InvId>"). params carries the provider's raw form fields; channel selects the
-func (c *Client) RobokassaResult(ctx context.Context, params map[string]string) (string, error) {
+// per-shop signature verifier (empty → the web shop).
+func (c *Client) RobokassaResult(ctx context.Context, channel string, params map[string]string) (string, error) {
 	var out robokassaResultResp
-	err := c.do(ctx, http.MethodPost, "/api/v1/internal/payments/robokassa/result", "", "", params, &out)
+	path := "/api/v1/internal/payments/robokassa/result"
+	if channel != "" {
+		path += "?channel=" + url.QueryEscape(channel)
+	}
+	err := c.do(ctx, http.MethodPost, path, "", "", params, &out)
 	return out.Response, err
 }
 

gateway/internal/backendclient/client.go

@@ -139,6 +139,26 @@ func platformFromContext(ctx context.Context) string {
 	return p
 }
 
+// clientIPCtxKey types the request-context slot the originating client IP rides in.
+type clientIPCtxKey struct{}
+
+// WithClientIP returns a copy of ctx carrying the originating client IP that do injects as
+// X-Forwarded-For on every downstream backend request — so the backend records the real caller
+// (the account's last-login IP, chat/feedback moderation, the access log) rather than the gateway's
+// own connection. An empty IP leaves ctx unchanged, so no header is sent.
+func WithClientIP(ctx context.Context, ip string) context.Context {
+	if ip == "" {
+		return ctx
+	}
+	return context.WithValue(ctx, clientIPCtxKey{}, ip)
+}
+
+// clientIPFromContext returns the client IP stored by WithClientIP, or an empty string when none.
+func clientIPFromContext(ctx context.Context) string {
+	ip, _ := ctx.Value(clientIPCtxKey{}).(string)
+	return ip
+}
+
 // do performs one REST call. userID, when non-empty, is forwarded as X-User-ID;
 // clientIP, when non-empty, as X-Forwarded-For (for chat moderation); the trusted
 // platform carried on ctx (see WithPlatform), when present, as X-Platform. A non-2xx
@@ -160,6 +180,13 @@ func (c *Client) do(ctx context.Context, method, path, userID, clientIP string,
 	if userID != "" {
 		req.Header.Set("X-User-ID", userID)
 	}
+	// The client IP rides X-Forwarded-For so the backend records the real caller. It comes from the
+	// explicit param (chat/feedback) or, for every other call, the request context (WithClientIP, set
+	// once per request in the Connect edge) — so the backend never falls back to the gateway's own
+	// connection address.
+	if clientIP == "" {
+		clientIP = clientIPFromContext(ctx)
+	}
 	if clientIP != "" {
 		req.Header.Set("X-Forwarded-For", clientIP)
 	}

gateway/internal/backendclient/client_test.go

@@ -122,3 +122,44 @@ func TestXPlatformInjection(t *testing.T) {
 		}
 	})
 }
+
+// TestXForwardedForInjection verifies the client IP carried on the context (WithClientIP) rides every
+// backend call as X-Forwarded-For — not just chat/feedback, which pass it explicitly — so the backend
+// records the real caller (e.g. the account's last-login IP on the profile fetch) rather than the
+// gateway's own connection. Absent when no client IP is set.
+func TestXForwardedForInjection(t *testing.T) {
+	var gotXFF string
+	var hadHeader bool
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotXFF = r.Header.Get("X-Forwarded-For")
+		_, hadHeader = r.Header["X-Forwarded-For"]
+		_, _ = w.Write([]byte(`{}`))
+	}))
+	defer srv.Close()
+
+	c, err := backendclient.New(srv.URL, "localhost:9090", 2*time.Second)
+	if err != nil {
+		t.Fatalf("backendclient: %v", err)
+	}
+	defer func() { _ = c.Close() }()
+
+	t.Run("client IP on ctx rides a non-chat call", func(t *testing.T) {
+		ctx := backendclient.WithClientIP(context.Background(), "203.0.113.7")
+		if _, err := c.Profile(ctx, "user-1"); err != nil {
+			t.Fatalf("Profile: %v", err)
+		}
+		if gotXFF != "203.0.113.7" {
+			t.Fatalf("X-Forwarded-For = %q, want 203.0.113.7", gotXFF)
+		}
+	})
+
+	t.Run("no client IP omits the header", func(t *testing.T) {
+		hadHeader = true
+		if _, err := c.Profile(context.Background(), "user-1"); err != nil {
+			t.Fatalf("Profile: %v", err)
+		}
+		if hadHeader {
+			t.Fatal("X-Forwarded-For must be absent when no client IP is set")
+		}
+	})
+}

gateway/internal/connectsrv/cors.go

@@ -0,0 +1,47 @@
+package connectsrv
+
+import "net/http"
+
+// nativeWebViewOrigins are the browser Origins of the packaged native apps. Capacitor serves the
+// bundled SPA from a localhost scheme, so its Connect calls to the gateway are cross-origin; the web
+// app is same-origin and needs no entry. Requests carry Authorization, so the allowlist reflects the
+// exact origin rather than "*".
+var nativeWebViewOrigins = map[string]bool{
+	"https://localhost":     true, // Capacitor Android (default https scheme)
+	"http://localhost":      true, // Capacitor with the http scheme
+	"capacitor://localhost": true, // Capacitor iOS default scheme
+}
+
+// withNativeCORS answers the CORS preflight and adds the CORS response headers for the packaged
+// native apps' cross-origin calls to the Connect edge. Without it the WebView blocks every RPC on the
+// preflight (the gateway otherwise returns 405 with no Access-Control-Allow-Origin), so a native
+// build can never reach the gateway and stays stuck offline. Same-origin (web) and any non-native
+// origin are untouched.
+func withNativeCORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		origin := r.Header.Get("Origin")
+		if nativeWebViewOrigins[origin] {
+			h := w.Header()
+			h.Set("Access-Control-Allow-Origin", origin)
+			h.Add("Vary", "Origin")
+			h.Set("Access-Control-Allow-Credentials", "true")
+			// The client interceptor reads the soft-tier update signal off the response.
+			h.Set("Access-Control-Expose-Headers", "X-Update-Recommended")
+			if r.Method == http.MethodOptions {
+				h.Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
+				// Reflect the requested headers (the origin is already allowlisted): the Connect client
+				// sends Connect-Protocol-Version / Connect-Timeout-Ms plus X-Client-Version and
+				// Authorization, and the exact set varies by call.
+				if reqHeaders := r.Header.Get("Access-Control-Request-Headers"); reqHeaders != "" {
+					h.Set("Access-Control-Allow-Headers", reqHeaders)
+				} else {
+					h.Set("Access-Control-Allow-Headers", "Content-Type, Connect-Protocol-Version, X-Client-Version, Authorization")
+				}
+				h.Set("Access-Control-Max-Age", "86400")
+				w.WriteHeader(http.StatusNoContent)
+				return
+			}
+		}
+		next.ServeHTTP(w, r)
+	})
+}

gateway/internal/connectsrv/cors_test.go

@@ -0,0 +1,54 @@
+package connectsrv
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestWithNativeCORS(t *testing.T) {
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) })
+	h := withNativeCORS(next)
+
+	// Native-origin preflight → 204 with the CORS headers, reflecting the requested headers, without
+	// reaching the inner handler.
+	req := httptest.NewRequest(http.MethodOptions, "/scrabble.edge.v1.Gateway/Execute", nil)
+	req.Header.Set("Origin", "https://localhost")
+	req.Header.Set("Access-Control-Request-Method", "POST")
+	req.Header.Set("Access-Control-Request-Headers", "content-type,connect-protocol-version,x-client-version")
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNoContent {
+		t.Fatalf("preflight status = %d, want 204", rec.Code)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Origin"); got != "https://localhost" {
+		t.Errorf("Allow-Origin = %q, want https://localhost", got)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Headers"); got != "content-type,connect-protocol-version,x-client-version" {
+		t.Errorf("Allow-Headers = %q, want the reflected set", got)
+	}
+
+	// Native-origin POST → the CORS headers are set and the inner handler runs.
+	req = httptest.NewRequest(http.MethodPost, "/scrabble.edge.v1.Gateway/Execute", nil)
+	req.Header.Set("Origin", "capacitor://localhost")
+	rec = httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("POST status = %d, want 200 (passed through)", rec.Code)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Origin"); got != "capacitor://localhost" {
+		t.Errorf("POST Allow-Origin = %q, want capacitor://localhost", got)
+	}
+
+	// A non-native origin gets no CORS headers and still passes through (web is same-origin anyway).
+	req = httptest.NewRequest(http.MethodPost, "/scrabble.edge.v1.Gateway/Execute", nil)
+	req.Header.Set("Origin", "https://evil.example")
+	rec = httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("non-native POST status = %d, want 200", rec.Code)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Origin"); got != "" {
+		t.Errorf("non-native Allow-Origin = %q, want empty", got)
+	}
+}

gateway/internal/connectsrv/robokassa_channel_test.go

@@ -0,0 +1,17 @@
+package connectsrv
+
+import "testing"
+
+func TestRobokassaChannel(t *testing.T) {
+	cases := map[string]string{
+		"/pay/robokassa/result":         "", // legacy bare path → the backend defaults to the web shop
+		"/pay/robokassa/result/":        "", // trailing slash, no channel → the web default
+		"/pay/robokassa/result/web":     "web",
+		"/pay/robokassa/result/android": "android",
+	}
+	for path, want := range cases {
+		if got := robokassaChannel(path); got != want {
+			t.Errorf("robokassaChannel(%q) = %q, want %q", path, got, want)
+		}
+	}
+}

gateway/internal/connectsrv/server.go

@@ -274,8 +274,11 @@ func (s *Server) HTTPHandler() http.Handler {
 	mux.Handle("/dict/", s.dictBytesHandler())
 	mux.Handle("/dl/", s.exportDownloadHandler())
 	// Direct-rail (Robokassa) return + callback routes: the server Result callback (the single
-	// crediting signal, proxied to the backend intake) and the browser Success/Fail redirects.
+	// crediting signal, proxied to the backend intake) and the browser Success/Fail redirects. The
+	// per-shop callback rides a channel suffix (/pay/robokassa/result/<channel>); the bare path is
+	// the legacy web shop. Caddy's /pay/* matcher already forwards both, so no Caddyfile change.
 	mux.Handle("/pay/robokassa/result", s.robokassaResultHandler())
+	mux.Handle("/pay/robokassa/result/", s.robokassaResultHandler())
 	mux.Handle("/pay/vk/callback", s.vkCallbackHandler())
 	mux.Handle("/pay/robokassa/success", s.robokassaReturnHandler("Оплата принята."))
 	mux.Handle("/pay/robokassa/fail", s.robokassaReturnHandler("Оплата не завершена."))
@@ -299,7 +302,7 @@ func (s *Server) HTTPHandler() http.Handler {
 	// honeypot hit is turned away before the body cap and the mux. Every request
 	// body on the public listener is then capped (the admin proxy POSTs included);
 	// the h2c server carries explicit stream/idle sizing.
-	return h2c.NewHandler(s.abuseGuard(maxBodyHandler(s.maxBodyBytes, mux)), &http2.Server{
+	return h2c.NewHandler(s.abuseGuard(withNativeCORS(maxBodyHandler(s.maxBodyBytes, mux))), &http2.Server{
 		MaxConcurrentStreams: h2cMaxConcurrentStreams,
 		IdleTimeout:          h2cIdleTimeout,
 	})
@@ -418,6 +421,10 @@ func (s *Server) Execute(ctx context.Context, req *connect.Request[edgev1.Execut
 		return nil, connect.NewError(connect.CodeNotFound, errUnknownMessageType(msgType))
 	}
 	clientIP := peerIP(req.Peer().Addr, req.Header())
+	// Carry the client IP on the context so the backend client injects it as X-Forwarded-For on every
+	// downstream REST call for this request — the account's last-login IP, chat/feedback moderation and
+	// the backend access log, not only the chat/feedback calls that pass it explicitly.
+	ctx = backendclient.WithClientIP(ctx, clientIP)
 
 	tr := transcode.Request{Payload: req.Msg.GetPayload(), ClientIP: clientIP}
 	if op.Auth {
@@ -465,6 +472,7 @@ func (s *Server) Execute(ctx context.Context, req *connect.Request[edgev1.Execut
 			return connect.NewResponse(&edgev1.ExecuteResponse{
 				RequestId:  req.Msg.GetRequestId(),
 				ResultCode: code,
+				Message:    transcode.DomainMessage(err),
 			}), nil
 		}
 		s.log.Error("execute failed", zap.String("message_type", msgType), zap.Error(err))
@@ -633,6 +641,21 @@ func (s *Server) exportDownloadHandler() http.Handler {
 	})
 }
 
+// robokassaResultPrefix is the channel-suffixed Result path; the segment after it names the
+// per-shop channel (matches the direct-rail X-Platform subtype: "web", "android").
+const robokassaResultPrefix = "/pay/robokassa/result/"
+
+// robokassaChannel extracts the shop channel from a Result callback path: the segment after
+// robokassaResultPrefix, or "" for the legacy bare /pay/robokassa/result (the backend then defaults
+// to the web shop). The backend selects the per-shop signature verifier from it.
+func robokassaChannel(path string) string {
+	rest := strings.TrimPrefix(path, robokassaResultPrefix)
+	if rest == path {
+		return ""
+	}
+	return rest
+}
+
 // robokassaResultHandler proxies the Robokassa Result callback to the backend intake (the single
 // writer). It rate-limits per IP, forwards the provider's form parameters, and echoes the backend's
 // "OK<InvId>" to Robokassa on success; any error tells Robokassa the notification was not accepted,
@@ -657,7 +680,7 @@ func (s *Server) robokassaResultHandler() http.Handler {
 		for k := range r.Form {
 			params[k] = r.Form.Get(k)
 		}
-		resp, err := s.backend.RobokassaResult(r.Context(), params)
+		resp, err := s.backend.RobokassaResult(r.Context(), robokassaChannel(r.URL.Path), params)
 		if err != nil {
 			s.log.Warn("robokassa result proxy failed", zap.Error(err))
 			http.Error(w, "not accepted", http.StatusBadGateway)

gateway/internal/transcode/transcode.go

@@ -189,6 +189,17 @@ func (r *Registry) Lookup(messageType string) (Op, bool) {
 	return op, ok
 }
 
+// DomainMessage returns the human-readable, already-localized reason a backend domain error carries
+// for the user (e.g. an operator's payment-unavailable explanation), or "" when it carries none. It
+// rides the Execute envelope's message field alongside the result code.
+func DomainMessage(err error) string {
+	var apiErr *backendclient.APIError
+	if errors.As(err, &apiErr) {
+		return apiErr.Message
+	}
+	return ""
+}
+
 // DomainCode maps an error to a stable result code to surface in the Execute
 // envelope, reporting false for an unexpected error the caller should treat as a
 // transport-level internal failure.
@@ -259,13 +270,14 @@ func authGuestHandler(backend *backendclient.Client) Handler {
 		// The guest bootstrap historically carried no payload; the detected zone is
 		// optional, so an absent or empty one simply yields no time-zone seed (rather
 		// than panicking in GetRootAs* on a zero-length buffer).
-		var browserTz, subtype string
+		var browserTz, subtype, locale string
 		if len(req.Payload) > 0 {
 			g := fb.GetRootAsGuestLoginRequest(req.Payload, 0)
 			browserTz = string(g.BrowserTz())
 			subtype = string(g.Subtype())
+			locale = string(g.Locale())
 		}
-		sess, err := backend.GuestAuth(ctx, browserTz, subtype)
+		sess, err := backend.GuestAuth(ctx, browserTz, subtype, locale)
 		if err != nil {
 			return nil, err
 		}

gateway/proto/edge/v1/edge.pb.go

@@ -98,6 +98,10 @@ type ExecuteResponse struct {
 	RequestId  string                 `protobuf:"bytes,1,opt,name=request_id,json=requestId,proto3" json:"request_id,omitempty"`
 	ResultCode string                 `protobuf:"bytes,2,opt,name=result_code,json=resultCode,proto3" json:"result_code,omitempty"`
 	Payload    []byte                 `protobuf:"bytes,3,opt,name=payload,proto3" json:"payload,omitempty"`
+	// message is an optional, already-localized human-readable reason a domain outcome may carry for
+	// the user (e.g. a payment-unavailable explanation set by an operator). Additive and
+	// frozen-contract-safe; empty for the common case where result_code alone suffices.
+	Message       string `protobuf:"bytes,4,opt,name=message,proto3" json:"message,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -153,6 +157,13 @@ func (x *ExecuteResponse) GetPayload() []byte {
 	return nil
 }
 
+func (x *ExecuteResponse) GetMessage() string {
+	if x != nil {
+		return x.Message
+	}
+	return ""
+}
+
 // SubscribeRequest opens the live stream. It is empty: the session is taken from
 // the Authorization header.
 type SubscribeRequest struct {
@@ -262,13 +273,14 @@ const file_edge_v1_edge_proto_rawDesc = "" +
 	"\fmessage_type\x18\x01 \x01(\tR\vmessageType\x12\x18\n" +
 	"\apayload\x18\x02 \x01(\fR\apayload\x12\x1d\n" +
 	"\n" +
-	"request_id\x18\x03 \x01(\tR\trequestId\"k\n" +
+	"request_id\x18\x03 \x01(\tR\trequestId\"\x85\x01\n" +
 	"\x0fExecuteResponse\x12\x1d\n" +
 	"\n" +
 	"request_id\x18\x01 \x01(\tR\trequestId\x12\x1f\n" +
 	"\vresult_code\x18\x02 \x01(\tR\n" +
 	"resultCode\x12\x18\n" +
-	"\apayload\x18\x03 \x01(\fR\apayload\"\x12\n" +
+	"\apayload\x18\x03 \x01(\fR\apayload\x12\x18\n" +
+	"\amessage\x18\x04 \x01(\tR\amessage\"\x12\n" +
 	"\x10SubscribeRequest\"P\n" +
 	"\x05Event\x12\x12\n" +
 	"\x04kind\x18\x01 \x01(\tR\x04kind\x12\x18\n" +

gateway/proto/edge/v1/edge.proto

@@ -35,6 +35,10 @@ message ExecuteResponse {
   string request_id = 1;
   string result_code = 2;
   bytes payload = 3;
+  // message is an optional, already-localized human-readable reason a domain outcome may carry for
+  // the user (e.g. a payment-unavailable explanation set by an operator). Additive and
+  // frozen-contract-safe; empty for the common case where result_code alone suffices.
+  string message = 4;
 }
 
 // SubscribeRequest opens the live stream. It is empty: the session is taken from