.gitea/workflows/ci.yaml

@@ -26,6 +26,13 @@ on:
   push:
     branches: [development]
 
+# The dictionary release the test suite validates against — the current
+# scrabble-dictionary release. Centralised here so a release bump is one edit; the
+# unit/integration jobs inherit it. The deploy job overrides it per contour with
+# vars.TEST_DICT_VERSION (the seed for a fresh volume), see deploy/README.md.
+env:
+  DICT_VERSION: v1.2.1
+
 jobs:
   # changes detects which areas a PR/push touched, so the test jobs can skip when
   # irrelevant. It defaults to running everything when the diff cannot be computed.
@@ -86,7 +93,6 @@ jobs:
       # The engine consumes the published scrabble-solver module from this Gitea;
       # GOPRIVATE makes go fetch it directly (skipping the public proxy/checksum DB).
       GOPRIVATE: gitea.iliadenisov.ru/*
-      DICT_VERSION: v1.0.0
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -134,7 +140,6 @@ jobs:
       # suite's TestMain terminates its own container, so disable it.
       TESTCONTAINERS_RYUK_DISABLED: "true"
       GOPRIVATE: gitea.iliadenisov.ru/*
-      DICT_VERSION: v1.0.0
     steps:
       - name: Checkout
         uses: actions/checkout@v4

PRERELEASE.md

@@ -38,6 +38,7 @@ the edge before prod. Each phase maps back to the owner's raw pre-release TODO l
 | BX | Asymmetric per-user block + in-game controls: a block now silently suppresses everything **from** the blocked user (chat, nudge, friend requests, invitations are kept but never delivered/surfaced, born-read) while they notice nothing, **without** deleting the friendship (unblock restores it); auto-match excludes a block-related pair (either direction); in-game opponent card gains a ✖️ **block** control (mirroring 🤝, red "Block?" confirm, mutual-hide, struck name + hidden chat composer when blocked); optimistic apply + `user_blocked`/`user_unblocked` event confirm + rollback; admin user card gains **blocks / blocked-by / friends** cross-linked lists. Blocking a disguised-robot opponent is recorded per-game in a separate **`robot_blocks`** table (migration `00011`), keyed on game+seat with the seen name — never the shared robot account — so the matchmaker keeps giving robots; it shows in the blocked list and re-marks the in-game card | owner ad-hoc | **done** |
 | FM | First-move tile draw (official rules): each seated player draws a tile, the one closest to "A" leads (a blank beats every letter), ties re-drawing until a single leader; **honest per-draw `crypto/rand` entropy**, not the bag seed, so the **record** (`game_setup_draws`, migration `00013`) — not a seed — is the only account of the outcome, kept for future **tournaments** (designed as a discrete per-tile "player N draws" step). Friend/AI draws at create; **auto-match draws at *open*** against a synthetic `uuid.Nil` opponent whose draw rows are back-filled on join, so the opener's seat is fixed up front and the existing open-game pre-move is preserved (no reseating, no play-gating). Admin `/_gm/games/:id` gains the recorded draw list + a simple **step-by-step board replay** (`ReplayTimeline`). | owner ad-hoc | **done** |
 | SB | Single Telegram bot + per-user variant preferences: the two per-language bots collapse into **one** (drop `accounts.service_language`, `supported_languages`, the `*_EN`/`*_RU` env vars and game-language push routing — the single bot renders in the recipient's `preferred_language`); New Game variant gating moves to a profile **`variant_preferences`** set (default Erudit only, Erudit-first, server-enforced on the caller's auto-match/vs-AI/invitation-create paths, an invited friend may accept any variant); env vars collapse to unsuffixed `TELEGRAM_BOT_TOKEN`/`TELEGRAM_GAME_CHANNEL_ID`/`VITE_TELEGRAM_LINK`/`VITE_TELEGRAM_GAME_CHANNEL_NAME` and `GATEWAY_DEFAULT_SUPPORTED_LANGUAGES` is removed; wire drops `service_language`/`supported_languages` (Session, ValidateInitDataResponse) + the push `language` routing field and adds `variant_preferences` to Profile/UpdateProfile. | owner ad-hoc | **done** |
+| DV | Dictionary version hygiene: CI + image/compose seed track the current release (`v1.2.1`); a **seed-drift guard** records the flat dir's seed in a `.seed_version` marker and refuses to boot when a bumped build seed would relabel a live volume (silently serving the wrong dictionary + voiding games pinned to the prior label); `DICT_VERSION` is the fresh-volume seed only, a live contour migrates through the admin console | owner ad-hoc | **done** |
 | → | Stage 18 — prod contour deploy | — | see [`PLAN.md`](PLAN.md) |
 
 ## Key findings (these reshaped the raw list — read before starting a phase)

backend/Dockerfile

@@ -12,7 +12,7 @@
 
 # --- dictionary artifact -----------------------------------------------------
 FROM alpine:3.20 AS dawg
-ARG DICT_VERSION=v1.0.0
+ARG DICT_VERSION=v1.2.1
 RUN apk add --no-cache curl tar
 RUN mkdir -p /dawg \
  && curl -fsSL -o /tmp/dawg.tar.gz \
@@ -40,7 +40,7 @@ FROM gcr.io/distroless/static-debian12:nonroot
 # Re-declare the build arg in this stage so it labels the seed dictionary. One
 # DICT_VERSION drives both the artifact the dawg stage downloads and the version
 # label the binary pins, so the resident version equals the release tag.
-ARG DICT_VERSION=v1.0.0
+ARG DICT_VERSION=v1.2.1
 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

backend/README.md

@@ -190,7 +190,7 @@ internal/ratewatch/  # gateway rate-limit reports: episode window for the consol
 | `BACKEND_OTEL_TRACES_EXPORTER` | `none` | `none`, `stdout` or `otlp` (gRPC; endpoint from the standard `OTEL_EXPORTER_OTLP_*`). |
 | `BACKEND_OTEL_METRICS_EXPORTER` | `none` | `none`, `stdout` or `otlp`. |
 | `BACKEND_DICT_DIR` | — | **Required.** Directory of committed `.dawg` dictionaries. |
-| `BACKEND_DICT_VERSION` | `v1` | Dictionary version new games pin. |
+| `BACKEND_DICT_VERSION` | `v1` | Seed dictionary version new games pin (the flat dir's label). Recorded in a `.seed_version` marker on first boot; the backend refuses to start if a later value drifts from it — the seed-drift guard (ARCHITECTURE.md §5). |
 | `BACKEND_GAME_TIMEOUT_SWEEP_INTERVAL` | `1m` | How often the turn-timeout sweeper runs. |
 | `BACKEND_GAME_CACHE_TTL` | `24h` | Idle window before a live game is evicted from cache. |
 | `BACKEND_LOBBY_ROBOT_WAIT` | `10s` | Auto-match wait before a robot is substituted for a missing human. |
@@ -212,7 +212,7 @@ internal/ratewatch/  # gateway rate-limit reports: episode window for the consol
 ```sh
 docker run -d --name scrabble-pg -e POSTGRES_PASSWORD=dev -p 5432:5432 postgres:17-alpine
 # DAWGs: extract the dictionary release artifact (or point at a local scrabble-solver/dawg):
-mkdir -p /tmp/dawg && curl -fsSL https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/v1.0.0/scrabble-dawg-v1.0.0.tar.gz | tar xz -C /tmp/dawg
+mkdir -p /tmp/dawg && curl -fsSL https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/v1.2.1/scrabble-dawg-v1.2.1.tar.gz | tar xz -C /tmp/dawg
 BACKEND_POSTGRES_DSN='postgres://postgres:dev@localhost:5432/postgres?search_path=backend&sslmode=disable' \
   BACKEND_DICT_DIR=/tmp/dawg \
   GOPRIVATE='gitea.iliadenisov.ru/*' \
@@ -251,7 +251,13 @@ local solver co-development you may add a temporary replace — see `go.work`).
 from the [`scrabble-dictionary`](https://gitea.iliadenisov.ru/developer/scrabble-dictionary)
 repo (one semver per set); the engine loads them by `(variant, dict_version)` from
 `BACKEND_DICT_DIR`. The backend loads them at startup as a hard dependency
-(a missing dictionary aborts the boot).
+(a missing dictionary aborts the boot). The flat directory is the seed version,
+labelled `BACKEND_DICT_VERSION`; uploaded versions live in `<version>/`
+subdirectories the admin console writes and a restart re-loads. Because the DAWGs
+carry no embedded version, the first boot records the seed in a `.seed_version`
+marker and a later boot **refuses to start** if `BACKEND_DICT_VERSION` no longer
+matches it (the seed-drift guard), so a live contour's dictionary is changed through
+the console, never by bumping the build seed (ARCHITECTURE.md §5).
 
 ## Tests
 

backend/internal/engine/registry.go

@@ -71,13 +71,21 @@ func Open(dir, version string, variants ...Variant) (*Registry, error) {
 // version V, the variants whose committed DAWG it carries. This is the
 // restart-side of the admin dictionary reload — a version reloaded into dir/<V>/
 // at runtime is resident again after a restart. A subdirectory named like the
-// boot version is skipped (the flat dir already is the boot version). A partially
+// boot version is skipped (the flat dir already is the boot version). It records
-// loaded registry is closed before any error is returned.
+// and enforces a seed-version marker on the flat dir (see checkSeedMarker), failing
+// when the build seed was bumped on an already-seeded volume. A partially loaded
+// registry is closed before any error is returned.
 func OpenWithVersions(dir, bootVersion string) (*Registry, error) {
 	r, err := Open(dir, bootVersion)
 	if err != nil {
 		return nil, err
 	}
+	// Guard the seed-drift footgun before scanning for additional versions: refuse
+	// to boot when the flat dir was seeded under a different version than bootVersion.
+	if err := checkSeedMarker(dir, bootVersion); err != nil {
+		_ = r.Close()
+		return nil, err
+	}
 	entries, err := os.ReadDir(dir)
 	if err != nil {
 		_ = r.Close()

backend/internal/engine/reload_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -112,6 +113,59 @@ func TestOpenWithVersionsSkipsDotDirs(t *testing.T) {
 	}
 }
 
+// TestOpenWithVersionsRecordsSeedMarker verifies the first boot records the seed
+// version in the flat dir's marker, the marker is not mistaken for a version, and a
+// reboot at the same seed version succeeds.
+func TestOpenWithVersionsRecordsSeedMarker(t *testing.T) {
+	dir := t.TempDir()
+	for _, v := range Variants() {
+		copyDawg(t, testDictDir(), dir, v)
+	}
+
+	reg, err := OpenWithVersions(dir, "v1")
+	if err != nil {
+		t.Fatalf("first open: %v", err)
+	}
+	if got := reg.Versions(VariantEnglish); len(got) != 1 || got[0] != "v1" {
+		t.Errorf("versions = %v, want only [v1] (marker not a version)", got)
+	}
+	_ = reg.Close()
+
+	data, err := os.ReadFile(filepath.Join(dir, seedMarkerFile))
+	if err != nil {
+		t.Fatalf("read seed marker: %v", err)
+	}
+	if got := strings.TrimSpace(string(data)); got != "v1" {
+		t.Fatalf("seed marker = %q, want v1", got)
+	}
+
+	reg2, err := OpenWithVersions(dir, "v1")
+	if err != nil {
+		t.Fatalf("reboot at same seed: %v", err)
+	}
+	_ = reg2.Close()
+}
+
+// TestOpenWithVersionsRejectsSeedDrift verifies the guard refuses to boot a directory
+// seeded as one version when BACKEND_DICT_VERSION (bootVersion) names another — the
+// seed-drift footgun a bumped build seed on a live volume would cause.
+func TestOpenWithVersionsRejectsSeedDrift(t *testing.T) {
+	dir := t.TempDir()
+	for _, v := range Variants() {
+		copyDawg(t, testDictDir(), dir, v)
+	}
+
+	reg, err := OpenWithVersions(dir, "v1")
+	if err != nil {
+		t.Fatalf("seed open: %v", err)
+	}
+	_ = reg.Close()
+
+	if _, err := OpenWithVersions(dir, "v2"); err == nil {
+		t.Fatal("open after seed bump: want error, got nil")
+	}
+}
+
 // TestReloadRegistersNewVersion verifies Load adds a second version to a variant
 // already resident, moves the latest pointer and keeps the earlier version.
 func TestReloadRegistersNewVersion(t *testing.T) {

backend/internal/engine/seedmarker.go

@@ -0,0 +1,52 @@
+package engine
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// seedMarkerFile names the file, in the flat dictionary directory, that records the
+// version the directory was first seeded as. It is dot-prefixed so OpenWithVersions'
+// version scan skips it (like the .staging upload area).
+const seedMarkerFile = ".seed_version"
+
+// checkSeedMarker reconciles the flat dictionary directory's recorded seed version
+// with bootVersion, guarding the seed-drift footgun.
+//
+// The contour's dictionary lives on a named volume seeded from the image once and
+// never re-seeded (deploy/docker-compose.yml). The flat directory's DAWG files carry
+// no embedded version, so their version is only the label BACKEND_DICT_VERSION gives
+// them. Bumping the build seed on a live volume would therefore relabel the already
+// seeded bytes: games that pinned the old label become unreplayable (voided) and new
+// games would silently use the wrong dictionary. checkSeedMarker records the seed
+// version on a fresh directory and, on every later boot, returns an error when
+// bootVersion no longer matches the recorded seed — so an operator changes a live
+// dictionary by uploading the new release through the admin console, or wipes the
+// volume to re-seed, never by bumping the build seed (docs/ARCHITECTURE.md §5).
+//
+// A directory that cannot be written makes the first record fail; that already breaks
+// the admin console (which writes version subdirectories here), so the error is
+// returned rather than swallowed, matching the package's fail-loud dictionary setup.
+func checkSeedMarker(dir, bootVersion string) error {
+	path := filepath.Join(dir, seedMarkerFile)
+	data, err := os.ReadFile(path)
+	switch {
+	case err == nil:
+		if recorded := strings.TrimSpace(string(data)); recorded != bootVersion {
+			return fmt.Errorf("engine: dictionary volume was seeded as %q but BACKEND_DICT_VERSION is %q; "+
+				"change a live dictionary by uploading the release through the admin console, or wipe the "+
+				"volume to re-seed — do not bump the build seed (docs/ARCHITECTURE.md §5)", recorded, bootVersion)
+		}
+		return nil
+	case errors.Is(err, os.ErrNotExist):
+		if err := os.WriteFile(path, []byte(bootVersion+"\n"), 0o644); err != nil {
+			return fmt.Errorf("engine: record dictionary seed marker %s: %w", path, err)
+		}
+		return nil
+	default:
+		return fmt.Errorf("engine: read dictionary seed marker %s: %w", path, err)
+	}
+}

deploy/.env.example

@@ -10,12 +10,13 @@ POSTGRES_USER=scrabble
 POSTGRES_PASSWORD=change-me            # required
 
 # --- Dictionary -------------------------------------------------------------
-# scrabble-dictionary release tag baked into the image as the SEED dictionary
+# scrabble-dictionary release tag baked into the image as the SEED dictionary for a
-# (image build-arg; also labels the resident seed version). After first boot the
+# FRESH volume (image build-arg; also labels the resident seed version). After first
-# dawg-data volume preserves versions uploaded through the admin console, and the
+# boot the dawg-data volume preserves versions uploaded through the admin console and
-# active version lives in the DB — so bumping this on a later deploy does NOT change
+# the active version lives in the DB. On a live volume the backend refuses to start if
-# a running contour; update the dictionary through /_gm/dictionary instead.
+# this no longer matches the recorded seed (the seed-drift guard) — change a running
-DICT_VERSION=v1.0.0
+# contour's dictionary through /_gm/dictionary, not by bumping this (ARCHITECTURE.md §5).
+DICT_VERSION=v1.2.1
 
 # --- Logging ----------------------------------------------------------------
 LOG_LEVEL=info

deploy/README.md

@@ -71,7 +71,7 @@ compose, but the connector **fails at boot** when it is empty.
 | --- | --- | --- | --- |
 | `POSTGRES_DB` | variable | `scrabble` | Database name. |
 | `POSTGRES_USER` | variable | `scrabble` | Database user. |
-| `DICT_VERSION` | variable | `v1.0.0` | `scrabble-dictionary` release tag baked into the backend image (build-arg). |
+| `DICT_VERSION` | variable | `v1.2.1` | `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; the backend refuses to boot if it drifts from the volume's recorded `.seed_version` (the seed-drift guard, ARCHITECTURE.md §5). Set per contour as `TEST_`/`PROD_DICT_VERSION`. |
 | `LOG_LEVEL` | variable | `info` | Shared log level for backend / gateway / connector (`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. |

deploy/docker-compose.yml

@@ -66,7 +66,9 @@ services:
       context: ..
       dockerfile: backend/Dockerfile
       args:
-        DICT_VERSION: ${DICT_VERSION:-v1.0.0}
+        # Seed dictionary for a FRESH volume; the per-contour value comes from the
+        # deploy env (Gitea TEST_/PROD_DICT_VERSION). See the volume note below.
+        DICT_VERSION: ${DICT_VERSION:-v1.2.1}
     restart: unless-stopped
     logging: *default-logging
     depends_on:
@@ -94,9 +96,11 @@ services:
     # (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
     # volume preserves them — and the versions in-progress games pin — across
-    # redeploys. Once seeded the volume is not re-seeded, so bumping DICT_VERSION on a
+    # redeploys. Once seeded the volume is not re-seeded: DICT_VERSION is the seed for
-    # later deploy has no effect on an existing contour; update via the console
+    # a FRESH volume only. On a live volume the backend refuses to start if DICT_VERSION
-    # instead (docs/ARCHITECTURE.md §5).
+    # no longer matches the recorded seed (the seed-drift guard), so a running contour's
+    # dictionary is changed through the admin console, never by bumping the seed
+    # (docs/ARCHITECTURE.md §5).
     volumes:
       - dawg-data:/opt/dawg
     # No container healthcheck: the distroless image has no shell/wget. Readiness

docs/ARCHITECTURE.md

@@ -273,9 +273,18 @@ Key points:
   skipping the `.staging/` upload area) and restores the active pointer from
   `dictionary_state`. The volume preserves uploaded versions across redeploys;
   once seeded it is not re-seeded, so after bootstrap dictionary changes go through
-  the console rather than a rebuild. (The dictionaries ship as a versioned
+  the console rather than a rebuild. Because the flat DAWGs carry no embedded
-  **release artifact** from the `scrabble-dictionary` repo; the build's
+  version, `OpenWithVersions` records the version the flat directory was first
-  `DICT_VERSION` selects only the seed.)
+  opened at in a `.seed_version` marker on the volume and **refuses to boot** when a
+  later `BACKEND_DICT_VERSION` disagrees — the **seed-drift guard**: it stops a
+  bumped build seed on a live volume from relabelling the already-seeded bytes,
+  which would silently serve the wrong dictionary and void games pinned to the prior
+  label. A running contour therefore moves to a new release **through the console**
+  (the prior version stays resident, so its games keep replaying); `DICT_VERSION` is
+  the seed for a **fresh** volume only, set per contour from the deploy's
+  `TEST_`/`PROD_DICT_VERSION`. (The dictionaries ship as a versioned **release
+  artifact** from the `scrabble-dictionary` repo; the build's `DICT_VERSION` selects
+  only the seed.)
 - 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**

loadtest/Dockerfile

@@ -12,7 +12,7 @@
 
 # --- dictionary artifact -----------------------------------------------------
 FROM alpine:3.20 AS dawg
-ARG DICT_VERSION=v1.0.0
+ARG DICT_VERSION=v1.2.1
 RUN apk add --no-cache curl tar
 RUN mkdir -p /dawg \
  && curl -fsSL -o /tmp/dawg.tar.gz \