scrabble-game/PRERELEASE.md

Pre-release plan — hardening before Stage 18

Living tracker for the pre-release hardening pass that runs before Stage 18 (the prod cutover). Same discipline as PLAN.md: one phase per session, interview the owner on the open details at the start of each phase, bake every decision back into PLAN.md / docs/ / the affected READMEs / Go Doc comments in the same PR, get CI green, then mark the phase done. Phases run as feature/* → development PRs (the Stage 16 branch model); the owner approves+merges.

Why now: the system is feature-complete through Stage 17 and the test contour is green, but there is no prod data yet — schema, wire labels and the dictionary layout can still change for free. These phases spend that one-time freedom and harden the edge before prod. Each phase maps back to the owner's raw pre-release TODO list (numbers in the tracker).

Phase tracker

#	Phase	Raw TODOs	Status
R1	Schema & naming reset	1 + 10	done
R2	Stress harness + contour observability + early run	9a	done
R3	Edge hardening	2 + 8 + 3	done
R4	Push enrichment + kill the last poll	4 + 5	done
R5	Bundle slimming	6	done
R6	Refactor + docs reconciliation + de-staging	7	done
R7	Final stress run + tuning	9b	done
UI	Tab-bar navigation redesign (drop the hamburger)	owner ad-hoc	done
MW	"Multiple words per turn" rule for Russian games (engine v1.1.0)	owner ad-hoc	done
MW2	Single-word rule connectivity fix: the word must run along its own line through an existing tile (perpendicular-only contact no longer connects); single-tile direction picks the best legal word (engine v1.1.1)	owner ad-hoc	done
MW3	Graceful replay degradation: a game whose journalled move became illegal under MW2 is closed as a draw (end_reason='aborted') on open instead of erroring, with an impersonal organizer note in the history + GCG (migration 00002)	owner ad-hoc	done
OW	Open auto-match: enter the game at once and wait inside it (robot after 90–180 s)	owner ad-hoc	done
DA	Dictionary admin: online release-archive upload → word-diff preview → install/activate; versioned dict volume; active version persisted in DB; resident label = release tag	owner ad-hoc	done
AB	Manual account block (admin suspension): permanent/temporary with an editable en+ru reason picklist; a block forfeits the player's active games + cancels their open ones; a backend gate refuses a blocked account with 403 account_blocked; the UI shows a terminal blocked screen and stops all push/poll; manual unblock; temporary blocks self-expire (migration 00003)	owner ad-hoc	done
AI	Honest AI opponent in quick game: an explicit 🤖 AI / 👤 random selector (AI default); the robot is seated and moves at once; 7-day inactivity loss (the per-turn timeout reused); chat/nudge disabled, no statistics; the opponent is shown as 🤖 everywhere	owner ad-hoc	done
AD	Advertising banner ("ad network"): server-driven weighted campaigns (percent weight + validity window; the perpetual default fills the remainder up to 100%), bilingual messages shown by bot (service_language); eligibility = free account + empty hint wallet + no no_banner role (guests included); the resolved feed rides profile.get with a notify banner re-poll on eligibility change; /_gm/banners admin + global display timings; client smooth-weighted-round-robin rotation + fade-out/gap/fade-in UX. A single app.load bootstrap aggregator was considered and deferred (see ARCHITECTURE §10).	owner ad-hoc	done (PR1 backend+admin, PR2 UI rotation)
GL	Simultaneous quick-game cap (10): grey "New Game" + a lobby notice at the cap; backend gate on quick enqueue + invitation creation (409 game_limit_reached), accepting invitations exempt; at_game_limit rides games.list	owner ad-hoc	done
CR	In-game chat read receipts: per-message unread_seats bitmask (migration 00008); a per-viewer unread dot in the lobby + game header (a nudge counts and clears when its recipient moves); reading = opening the move history (the 💬 fade-blinks twice) or the chat, acked (chat.read) only when unread; chat_read_duration + chat_unread_messages metrics + tracing; admin unread-only filter / read column / per-seat read card	owner ad-hoc	done
→	Stage 18 — prod contour deploy	—	see PLAN.md

Key findings (these reshaped the raw list — read before starting a phase)

• R1 (TODO 1 + 10) is one cheap moment, now. Squashing the 12 goose migrations is safe precisely because there is no prod data and the contour DB is wiped. Folding the new variant labels (scrabble_ru/scrabble_en/erudit_ru) into that single baseline makes the rename need no data migration and no back-compat mapping. Today's labels (english/russian_scrabble/erudit) are persisted in games.variant, game_invitations.variant, in pkg/fbs and the UI — ~100 files, but a mechanical sweep on a clean DB.
• R4 (TODO 4 + 5): the app is already push-first. Game state refreshes on your_turn/opponent_moved, the lobby on notify, chat on chat_message. The only genuine periodic server poll is lobby.poll (matchmaking, 2.5 s, ui/src/screens/NewGame.svelte). What remains is killing that one poll and enriching push events to carry payloads so the UI stops re-fetching after each signal.
• R3 (TODO 2): identity forgery is already mitigated. Identity is always derived from the session (Authorization: Bearer → X-User-ID); the client cannot inject identity, the backend re-validates resource ownership, Telegram initData is HMAC-checked. The real gaps are a missing request-body size limit (cheap DoS) and invisible rate-limit rejections (no log/metric/admin view — that is TODO 8). Static landing serving is not covered by the gateway token bucket (it only guards Execute).
• R6 (TODO 7) scale: ~431 Stage N references across ~104 files (incl. the file name backend/internal/inttest/stage6_test.go). Code is the source of truth; docs/ describe current state; PLAN.md keeps the decision history.

Locked decisions (owner interview)

• Stress test (TODO 9): early + final runs. Driver = edge protocol (Connect/FB through the gateway, moves generated by the solver) plus a separate gateway-hammer saturation test. Pacing = realistic (under limits) + saturation (ramp to the knee). Resource metrics = add cAdvisor + postgres_exporter to the contour (today only Go-runtime metrics exist). The harness stays in the repo for repeats.
• Push (TODO 4 + 5): both — kill lobby.poll (use the existing match_found, keep poll as the ws-down fallback) and enrich push events with payloads.
• Refactor (TODO 7): hygiene + structural changes by a reviewed list — behaviour-preserving, test-gated, contentious items surfaced to the owner before applying.
• Landing (TODO 3): separate static container behind the project caddy (/ → landing, /app/ + /telegram/ → gateway); drop landing.html from the gateway go:embed.
• Rate-abuse (TODO 8): metric + Grafana + admin view plus a conservative auto-flag — a soft, reversible "suspected high-rate" marker for operator review, tunable threshold, no auto-ban.
• Open auto-match (owner ad-hoc): a quick game enters a real game at once and waits inside it (status open, the opponent seat empty); a second human searching the same variant+rule joins it, or a robot fills it after a 90 s + random 0–90 s wait, pushing the in-app opponent_joined event. While open, the starter may move on their turn but resign, chat and nudge are disabled, and the lobby + opponent card read "searching for opponent". Matchmaking is now DB-backed open games — the in-memory pool, lobby.poll and lobby.cancel are gone. The schema is edited in the baseline (no prod data); game_players.account_id is nullable for the empty seat.

Phases

Each phase: read this tracker + the relevant docs/, interview the owner on the open details below, implement within scope, then update the tracker + docs/code and get CI green before marking it done.

R1 — Schema & naming reset (TODO 1 + 10) — first

Squash backend/internal/postgres/migrations/00001..00012 into one 00001_baseline.sql (method: pg_dump --schema-only from a fully-migrated DB → wrap as the goose baseline → prove a fresh migrate yields a schema identical to the 12-migration chain via the integration suite → delete the old files; keep goose). Bake the new variant labels into the baseline. Propagate scrabble_ru/scrabble_en/erudit_ru through the backend (engine.Variant/ParseVariant, registry.dictFiles, the CHECK values), the wire (pkg/fbs variant:string, regenerate FB) and the UI (lib/model.ts union, variants.ts, fixtures, premium/alphabet keys, tests); i18n display keys stay display-only. Tidy ../scrabble-dictionary to a single source→dawg build point and align the dawg artifact names to the new labels (crosses into ../scrabble-solver's committed fixtures — keep them byte-identical). After merge, wipe the contour DB (drop the volume) so it re-provisions on the next deploy.

• Critical files: backend/internal/postgres/migrations/, backend/internal/engine/{engine,registry}.go, pkg/fbs/scrabble.fbs, ui/src/lib/{model,variants}.ts, ../scrabble-dictionary/{Makefile,cmd/builddict,…}.
• Open details to interview: the exact dawg filename scheme; whether the dict-repo tidy is one PR or split; how to script the contour DB wipe in the deploy.

R2 — Stress harness + contour observability + early run (TODO 9, part 1)

Build the reusable load harness as a new loadtest module in go.work (reuses pkg/fbs, connect-go, and scrabble-solver for legal-move generation): a seeder that inserts 1000 guest + 10000 durable accounts with pre-created sessions (token hashes) directly in the DB and hands the plaintext tokens to the client; a driver that runs N virtual users, each in 3–5 concurrent 2–4-player games, exercising submit-play / pass / exchange / nudge / chat / check-word / draft-move / profile-save through the edge protocol, in realistic (under rate limits) and saturation (ramp) modes; plus a separate gateway-hammer that deliberately exceeds limits to verify the limiter holds and measure its cost. Add cAdvisor + postgres_exporter to deploy/docker-compose.yml and a Grafana resource dashboard. Run the early pass against the freshly-wiped contour; produce a trip report (logic/concurrency bugs + a resource baseline) that feeds R3 and R6.

• Critical files: new loadtest/, deploy/docker-compose.yml, deploy/observability/*, docs/TESTING.md.
• Open details: the scale ramp steps; the move-selection policy (a mid-ranked solver move for realistic game progress); run duration; the pass/fail bar.

R3 — Edge hardening (TODO 2 + 8 + 3)

Add a request-body size cap at the gateway h2c mux / Execute (e.g. ~1 MB). Add rate-limit observability: a gateway_rate_limited_total{class} counter + a structured log per rejection; an aggregate Grafana panel (request rate + rejection rate — spikes visible without per-user label cardinality, honouring the Stage 12/17 discipline); an admin-console view of recently throttled users/IPs (in-memory ring buffer, single- instance, reset-on-restart, like the active_users gauge). Add the conservative auto-flag: when a user is sustained-throttled past a tunable threshold, set a soft, reversible account.flagged_high_rate_at marker (baked into the R1 baseline) surfaced in the admin user list/detail — no auto-ban; the operator clears it. Split the landing into its own static container (deploy/ + a Caddyfile route / → landing) and drop landing.html from the gateway go:embed.

• Critical files: gateway/internal/connectsrv/server.go, gateway/internal/ratelimit/, gateway/internal/connectsrv/metrics.go, backend/internal/adminconsole/, deploy/caddy/Caddyfile, deploy/docker-compose.yml, gateway/internal/webui/.
• Open details: the auto-flag threshold/window + whether the marker is persisted vs in-memory; the landing image base (caddy vs nginx).

R4 — Push enrichment + kill the last poll (TODO 4 + 5)

Replace lobby.poll with the existing match_found push (keep the poll as a ws-down fallback). Enrich your_turn/opponent_moved/notify to carry the state payload so the UI renders from the event without a follow-up game.state (removes the lobby↔game nav latency the owner noticed). Wire-contract change: pkg/fbs event payloads → backend notify emit → UI stream consumers (ui/src/lib/app.svelte.ts), with the per-game cache as the landing spot; regenerate FB.

• Critical files: pkg/fbs/scrabble.fbs, backend/internal/notify/events.go, ui/src/lib/{app.svelte,transport}.ts, ui/src/screens/NewGame.svelte.
• Open details: which events carry full vs delta payloads; the fallback-poll cadence when the stream is down.

R5 — Bundle slimming (TODO 6) — done

Analysed the bundle against the 100 KB-gzip budget; no code slimming was warranted, and the budget metric was retargeted to measure the app correctly. The build already minifies + tree-shakes; the dominant cost is the Connect/FlatBuffers transport runtime + generated bindings

• the Svelte runtime (≈⅔ of main's source is third-party/generated) — irreducible within scope. Lazy-loading was rejected: bundle-size.mjs sums every emitted chunk, so code-splitting yields no total-size win and adds request latency (+N gateway fetches on first navigation to a split screen). i18n lazy-load was skipped (the catalogs are a sliver of a Svelte-runtime-dominated shared chunk, and en must stay bundled as the MessageKey type source + fallback). Instead, bundle-size.mjs now measures per HTML entry, with three independent gates on the natural chunk boundaries — app entry ≤ 100 KB, the Svelte+i18n shared chunk ≤ 30 KB, the landing's own chunk ≤ 5 KB — since the app's real payload is its entry chunk plus the shared chunk (≈97 KB), while the landing (≈24 KB) is reported separately and kept minimal. Same CLI + exit-code contract, so the CI step is unchanged.

• Critical files: ui/scripts/bundle-size.mjs; no app code changed.

R6 — Refactor + docs reconciliation + de-staging (TODO 7) — done

Behaviour-preserving only. Three separable, separately-committed passes: (a) mechanical de-staging — remove Stage N/TODO-N references from code, comments and service READMEs (rename stage6_test.go); (b) docs↔code reconciliation — reconcile docs/ARCHITECTURE.md / docs/FUNCTIONAL.md(+_ru) against the code-as-truth, fixing drift and Go Doc comments; (c) structural changes by a reviewed list — surface a list of proposed optimizations / test-suite consolidations to the owner, apply only the approved, behaviour-preserving, test-gated ones. The full suite + the final stress run (R7) are the regression gate. Incorporates the early-run (R2) bug fixes not already shipped.

• Open details: the structural-changes list itself (owner-approved before applying); the test consolidation targets.

R7 — Final stress run + tuning (TODO 9, part 2) — done

Re-run the R2 harness against the final, refactored system on a clean contour; analyse resource consumption across all components (gateway, backend, Postgres, the metrics/observability stack, docker log volume) and agree the tuning (pool sizes, rate limits, cache TTLs, container limits, GOMAXPROCS, log levels). Apply the agreed tuning; record the methodology + results in the repo.

→ Stage 18 (prod contour) then proceeds per PLAN.md.

Sequencing rationale

R1 first (cheapest now; everything builds on the final schema/naming and the stress test must run against it). R2 builds the harness and runs the early pass to surface bugs and a resource baseline that feed R3 and R6. R3/R4/R5 harden and improve the system. R6 (de-stage + reconcile + structural) runs near the end so it sweeps settled code once and benefits from all accumulated bug knowledge. R7 validates the final system and tunes it. Then Stage 18.

Regression-safety discipline (cross-cutting)

• Every phase is a feature/* → development PR; CI (unit + integration + ui behind the CI / gate check) must be green before the owner merges; watch the post-merge contour deploy with gitea-ci-watch.py.
• R6 structural changes are behaviour-preserving, test-gated, and split from the mechanical sweeps; contentious items are owner-approved first.
• The two stress runs (R2 early, R7 final) are the system-level regression gate.

Verification (per phase)

• go build ./<module>/..., go vet, gofmt -l . clean, go test -count=1 ./<module>/...; UI: pnpm check && pnpm test:unit && pnpm build; the integration suite (-tags integration) for DB/schema changes; docker compose config for deploy changes; green CI on the PR + a healthy contour deploy.
• R1: prove the squashed baseline yields a schema identical to the 12-migration chain (integration suite on a fresh DB) before deleting the old files.
• R2/R7: the harness runs end-to-end against the contour; the trip report lists concrete defects + a resource profile from the Grafana cAdvisor/postgres_exporter panels.

Refinements logged during implementation

• R1 (interview + implementation):

  • Variant labels english/russian_scrabble/erudit → scrabble_en/scrabble_ru/erudit_ru across the backend (engine.Variant.String/ParseVariant; the games/game_invitations variant CHECK in the baseline; GCG #lexicon and the variant metric attribute both flow from String), the wire (pkg/fbs variant is a string field — values change with no FlatBuffers regen) and the UI (model.ts union, variants.ts records, codec/premiums/mocks/tests, the admin dictionary.gohtml). Kept: the Go enum identifiers (VariantEnglish…, internal) and the i18n display keys (new.english/new.russian/new.erudit, display-only). complaints.variant stays free-text (no CHECK, as before).
  • dawg filenames kept descriptive (en_sowpods/ru_scrabble/ru_erudit) — only the registry's Variant key carries the rename, so registry.go, the published scrabble-solver fixtures and the dictionary release artifact are untouched (decouples the three repos).
  • Migrations squashed 12 → one hand-written 00001_baseline.sql. Verified by a pg_dump --schema-only diff (the chain vs the baseline are identical but for the two intended variant-CHECK values) plus the green integration suite. No data migration (no production data).
  • Done (cross-repo + contour): the scrabble-dictionary tidy merged (PR #2) and was re-cut as the byte-identical v1.0.1 release for clean provenance (the backend stays on v1.0.0 — same bytes, no rewire; the backend pulls a version-pinned release artifact, not master). Post-merge the contour backend schema was wiped (DROP SCHEMA backend CASCADE + restart, not a volume drop) and re-migrated to the baseline — verified the new variant CHECK (scrabble_en/scrabble_ru/erudit_ru), games=0 and a clean boot.

• R2 (interview + implementation):

  • Locked decisions: game assembly via invitations (real path, no robots; not direct game-row inserts); moderate ramp 50 → 200 → 500 at 10 min/step; diagnostic pass bar (no SLO gate); run as a one-shot container on scrabble-internal in this PR.
  • Harness = new scrabble/loadtest module (use ./loadtest + a replace scrabble/gateway for the dot-free edge-proto import). It seeds 1000 guest + 10000 durable accounts + sessions directly in Postgres (token hash mirrors backend/internal/session), drives players over the edge protocol, generates mid-ranked legal moves locally with the embedded scrabble-solver by replaying game.history (the edge carries no board — mirrors engine.ReplayBoard via the public API), and a gateway-hammer. Compact CLI (run / cleanup), distroless Dockerfile (DAWGs baked), Go unit tests.
  • Adding the module broke the other images' builds — backend/gateway/telegram Dockerfiles reduce the workspace but still referenced ./loadtest (not in their context); each now also -dropuse=./loadtest (backend/telegram additionally -dropreplace the gateway replace). Caught by the first deploy run; verified by building all four images.
  • Harness payload fixes found by the smoke pass: the draft DTO's rack_order is a string (was sent as [] → bad_request); the display-name validator forbids digits/colons, so the cleanup marker became a letters-only Zzloadtest so profile.update resends the seeded name. chat_not_your_turn / nudge_own_turn are by-design turn gates, correctly exercised.
  • Observability: added cAdvisor + postgres_exporter + the Scrabble — Resources dashboard + two Prometheus jobs. Finding: cAdvisor yields only the root cgroup on the contour host (separate XFS /var/lib/docker breaks its layer-ID resolution — the existing galaxy deploy has the same limit), so per-container CPU/RSS for the early pass was captured via docker stats. R7: adopt the otelcol docker_stats receiver (already the contrib image) for per-container metrics in Grafana.
  • Early run (2026-06-09): ramped clean to 500 players, no crash/deadlock, cleanup removed all 11000 accounts. 1.2 M edge calls, 48 870 plays, 2 798 games finished; the per-user limiter held under the hammer (99.97 % rejected, p99 2 ms). Top finding: ~14 % transport_error on game.state at 500 players, under CPU saturation (backend/gateway/Postgres each ~1 core) and amplified by the harness's single shared http2.Transport; the harness itself peaked at 86 % of a core on the same host, so the figures are pessimistic. Full trip report in ../loadtest/REPORT-R2.md; it feeds R3 (h2c MaxConcurrentStreams/timeouts, body-size cap), R6 and R7 (per-player transports, separate hardware, pool/limit sizing).
  • CI: ./loadtest/... added to the path filter + vet/build/test; go.work.sum carries the new deps.

• R3 (interview + implementation):

  • Locked decisions: the flag column lands by editing the R1 baseline (+ a contour schema wipe after merge — no migration chain accrues before prod); auto-flag defaults 1000 rejected / 10 min (BACKEND_HIGHRATE_FLAG_THRESHOLD/_WINDOW, rolling window, set-once, operator clears, no auto-ban); landing image = caddy:2-alpine; throttle data flows gateway → backend (a 30 s per-key summary POST to the new /api/v1/internal/ratelimit/report, the existing trusted direction) with the episode window + flag rule in the backend (internal/ratewatch); rejection logging = Warn summary per key per window + Debug per rejection — a deliberate deviation from the phase's "structured log per rejection" (the R2 hammer would have logged ~522k lines in minutes); all three R2-report tails included (explicit h2c sizing, the session-resolve failure cause at Warn, reviving the admin limiter).
  • Body cap: GATEWAY_MAX_BODY_BYTES (default 1 MiB) as both the Connect per-message read limit and an http.MaxBytesReader wrap of the public mux; an oversized Execute is resource_exhausted.
  • Dead config found: AdminPerMinute/AdminBurst were never wired — the gateway /_gm mount is now 429-guarded per IP ahead of its Basic-Auth. The caddy-fronted contour path stays unlimited (stock caddy has no limiter) — an accepted gap, recorded in docs/ARCHITECTURE.md §12.
  • Landing split: a landing target in gateway/Dockerfile (the UI build stage is shared; identical compose build args keep it one cached build); the gateway drops landing.html from the embed and 308-redirects / → /app/; the contour caddy routes /app/, /telegram/ and the Connect path to the gateway and the catch-all to the landing container; the CI deploy probe now checks both / (landing) and /app/ (gateway).
  • Observability: gateway_rate_limited_total{class} (user/public/email/admin, aggregate-only)
    • a rate-vs-rejections panel on the Edge/UX dashboard; the admin console gains the Throttled page (the in-memory episode window, reset-on-restart like active_users, plus the flagged-account queue) and the flag badge / clear action on the user list / card.
  • The jet regen also restored the previously missing game_drafts/game_hidden generated models (their tables were added after the last jetgen run; no behaviour change).

• R4 (interview + implementation):

  • Locked decisions: delta-first, not full snapshots — an event carries only the new move and the UI applies it to its per-game cache, keyed on move_count (idempotent + gap-safe: a gap or the actor's own move falls back to a game.state + game.history refetch). match_found / game_started carry the recipient's initial StateView (instant lobby→game); the fallback refetch stays the existing two calls (no merged endpoint); the matchmaking poll runs only while the stream is down (2.5 s); all UI-state-changing events carry their payload (incl. lobby notify).
  • Enriched events (pkg/fbs trailing fields — backward-compatible, no FB regen of values, only the schema): opponent_moved (+move/game/bag_len), your_turn (+move_count), match_found (+state), game_over (+game), notify (+account/invitation/state). The pre-R4 opponent_moved scalars (seat/action/score/total) stay for wire back-compat, now redundant with move/game — slated for the R6 de-stage.
  • Encoding placement: the notify package keeps ownership of the FlatBuffers encoding (a new encode.go mirrors the gateway transcode but reads wire-agnostic notify.* input structs + engine.MoveRecord); the game/lobby/social services map their domain types to those structs, so the wire schema stays out of the domain. Flagged for R6: this partly duplicates the gateway encoders (different source types) — a candidate consolidation.
  • Actor self-fetch killed too (beyond literal "push"): the submit_play/pass/exchange/resign response (MoveResult) now returns the actor's refilled rack + bag size, so the mover renders the next turn from the response — Game.svelte's commit/pass/exchange/resign drop their await load().
  • match_found enrichment needs a per-seat initial state: lobby.GameCreator gained InitialState, and game.Service.InitialState builds the notify.PlayerState (rack re-encoded to wire indices, the variant alphabet embedded for a first-seen variant).
  • UI: a pure lib/gamedelta.ts reducer (applyMoveDelta / applyGameOver / seedInitialState, unit-tested) advances the cache; app.svelte seeds it on match_found / game_started; Game.svelte applies the delta (falling back to load() while composing, on a gap, or on its own move's new rack); NewGame.svelte polls only when app.streamAlive is false and guards its teardown so a push-delivered match is not cancelled.
  • notify (friends/invitations) scope: the backend carries the full account / invitation payload on the wire (per "all events → push"); the UI seeds the game cache from game_started but keeps its lightweight authoritative badge refresh (refreshNotifications, on the rare notify event + on foreground) rather than adding client-side friend/invitation caches — the per-move hot path is fully de-fetched, which was the goal. Deeper lobby-cache consumption is an easy follow-up.
  • No schema change (no migration); the contour needs no DB wipe. Tests: notify FB round-trips + emitMove delta + the gamedelta reducer; the e2e mock now emits the enriched delta.

• R5 (interview + implementation):

  • No code slimming — by analysis. A gzip measure + sourcemap attribution of the real dist showed the app bundle is already minified + tree-shaken and dominated by the Connect/FlatBuffers transport runtime + generated FB/PB bindings (≈⅔ of main's source) and the Svelte runtime — all third-party/generated, irreducible within R5's scope. App-authored code carries no hand-trimmable fat.
  • Lazy-load rejected (screens and i18n): bundle-size.mjs sums every emitted chunk, so code-splitting moves bytes between chunks for zero total-size win while adding request latency (+N gateway fetches on first navigation to a split screen). i18n lazy-load additionally buys ≤3 KB (en-only users) at the cost of an async t(), and en must stay bundled (it is the MessageKey type source + fallback). Chunk-collapsing rejected too — keeping the near-static Svelte runtime in its own cacheable chunk is the recommended practice (an app deploy then re-busts only main, not the runtime), and HTTP/2 makes the extra preload request negligible.
  • Metric retargeted to the app. The two-entry build (index.html app + landing.html) makes Rollup hoist the code shared by both (Svelte runtime + i18n + aboutContent) into one preloaded chunk, so the app actually loads its entry chunk + the shared chunk (≈74 + ≈23 = ≈97 KB), never landing.js (≈1.6 KB). The old script summed all three chunks (98.8 KB), over-counting the app by landing.js. bundle-size.mjs now parses each built HTML for the JS it eagerly loads and gates three parts independently — app entry ≤ 100 KB, shared (Svelte+i18n) ≤ 30 KB, landing-own ≤ 5 KB — reporting the app total (≈97) and landing total (≈24.5). Same CLI + exit-code contract, so the CI step is unchanged.
  • No app/source/build change (App.svelte, lib/i18n/, vite.config.ts untouched); no schema change, no contour wipe. The stale "~82 KB" figure was corrected in bundle-size.mjs and ui/README.md.

• R6 (interview + implementation):

  • Locked decisions: apply both wire/code structural changes (B + A) and only C1+C2 of the test consolidation (not C3/C5); strip the *(Stage N)* tags from all current-state docs (ARCHITECTURE / FUNCTIONAL+_ru / TESTING / UI_DESIGN), keeping PLAN.md / PRERELEASE.md / CLAUDE.md as history; split stage6_test.go by domain. The h2cMaxConcurrentStreams sizing stays an R7 concern (tuning, not behaviour-preserving); the R2 early run forced no code fix, so nothing was carried in.
  • (a) De-staging: removed the Stage N / TODO-N / (RN) references across code, comments, service READMEs and the current-state docs, rewording narratives to present tense (no technical content lost). Renamed the only stage-named identifiers (registerStage8→registerSocialOps, registerStage11→registerLinkOps) and split stage6_test.go (TestEmailLoginFlow→email_test.go; TestGuestAutoMatchLeavesNoStats+provisionGuest→account_test.go). De-staged the .fbs/.proto comments and regenerated: only the .proto-derived Go docstrings (*_grpc.pb.go, push.pb.go) changed — flatc strips schema comments, so the FB Go/TS bindings were untouched.
  • (b) Reconciliation: the docs were accurate (each R-phase baked its own); the one drift was a stale "guest-reaping deferred (TODO-3)" note in ARCHITECTURE.md §3 — guest reaping is implemented, so the note was replaced with the current behaviour (FUNCTIONAL/TESTING already described it).
  • (c) B — dead opponent_moved scalars: removed seat/action/score/total from OpponentMovedEvent (pkg/fbs/scrabble.fbs + the notify emit + the round-trip test); regenerated FB Go + TS. No reader used them (the UI codec/mock take move/game/bag_len; the gateway forwards the payload verbatim). A pre-release wire-slot renumber — free with no prod data, no DB change.
  • (c) A — shared FB builders: new scrabble/pkg/wire holds the single definition of the nested wire tables (GameView / MoveRecord / StateView / AccountRef / Invitation) shared by the backend notify encoder and the gateway transcode; both map their own source types to neutral wire.* structs and delegate. Honest tradeoff: the verbose Start/Add/End + reverse-prepend boilerplate is now written once, but the field set is still mapped per side, and the new package makes the change net +~145 LOC — a single-source / anti-drift win for the fiddly mechanics rather than a line-count cut. Behaviour- preserving: the two sides' field sets were verified identical and the round-trip tests pass unchanged.
  • (c) C1+C2 — inttest fixtures: moved the cross-file service/game fixtures (newGameService was used by 10 files) into backend/internal/inttest/helpers.go; single-file helpers stay local. Pure relocation.
  • No schema change → no contour DB wipe. Regression gate: the full unit + integration + UI suites plus the R7 stress run.

• R7 (interview + implementation):

  • Locked decisions: run the harness same-host (one-shot container on scrabble-internal, capped --cpus=3 so the contour keeps spare cores); apply container limits + GOMAXPROCS now (not just a prod recommendation); replace cAdvisor with the otelcol docker_stats receiver (it resolved only the root cgroup on this host); keep rate-limit / h2c knobs compiled-in (change values only if the data demands — it did not).
  • Harness refinements (pre-run): each virtual player builds its own edge.Client (its own h2c connection for its Subscribe stream + Execute calls) instead of all players sharing one http2.Transport — the R2 transport_error artifact; and playTurn now reports a finished game so the player drops it from rotation. Effect, measured: game.state transport_error 14 % (R2) → 2.49 %; game_finished on chat ≈ 3 900 → 35.
  • Observability: added the docker_stats receiver to otelcol (api_version: "1.44" — the daemon's minimum is 1.40; the receiver defaults to 1.25 and crash-looped until pinned), mounted the docker socket read-only with group_add (the contrib image runs as UID 10001), dropped the cAdvisor service + its Prometheus job, and retargeted the Scrabble — Resources dashboard to the docker_stats metric names (container_cpu_utilization/100 == cores). Cross-checked against docker stats within sampling error.
  • Profile (final run, 500 players, limits in force): the gateway is the binding constraint — with one connection per player it bursts into its 2-core cap (the residual 2.49 % transport_error); backend ~0.85 core and postgres ~1.4 cores had headroom; tempo reached its 1 GiB cap; the backend pool sat at its MaxOpenConns=25 cap (28 backends); docker logs were unbounded (~14 MiB / 30 min on the backend at info). Full write-up in ../loadtest/REPORT-R7.md.
  • Round-2 tuning (owner-agreed, all in deploy/docker-compose.yml, no code change): gateway 2 → 3 cores + GOMAXPROCS=3; tempo memory 1 → 2 GiB; backend MAX_OPEN_CONNS 25 → 40; a json-file log-rotation default (10m × 3) applied contour-wide via a YAML anchor (level stays info). backend/postgres kept at 2 cores / 512 MiB (headroom is cheap on the shared host).
  • Validation: the same gradual ramp on the tuned contour cut game.state transport_error to 0.72 % (gateway ~2 cores, now under the 3-core cap, no throttle; tempo ~1.27 GiB, under 2 GiB). A separate burst run (a single 100 → 500 jump) pegged the gateway at 3 cores (≈296 % sustained, 9.27 % error), confirming it is connection-CPU-bound — a true arrival spike is a horizontal-scaling lever, not more cores per node (recorded in the prod-sizing recommendation).
  • No schema change → no contour DB wipe. Bake-back: loadtest/REPORT-R7.md (new), loadtest/README.md, docs/TESTING.md, the telemetry/observability section of docs/ARCHITECTURE.md, the repo-layout line in CLAUDE.md.

• UI — Tab-bar navigation redesign (owner ad-hoc, not on the raw TODO list): drop the hamburger Menu.svelte everywhere (it fought the Telegram-fullscreen layout, where it had to be re-centred).

  • Locked decisions (interview): the in-Settings sub-nav is a bottom TabBar with the active tab highlighted (icon-only); Export GCG moves to the left slot of the move-history header (free in a finished game, where 🏁 leave does not apply); the lobby ⚙️ badge counts incoming friend requests only (invitations keep their own lobby section); unread chat is badged on the score bar and the 💬.
  • What shipped: a ⚙️ Settings hub (screens/SettingsHub.svelte) over the existing Settings/Profile/Friends/About bodies and an in-game comms hub (game/CommsHub.svelte) over chat + dictionary, both with in-place tabs and a fixed back target; the game's menu items relocate into the open move history (🏁 leave / 📤 export + 💬 comms header) and the player cards (🤝 add-friend); a shared TapConfirm (components/TapConfirm.svelte, lib/tapconfirm.ts) — tap → fading ✅ → tap — replaces the Skip/Hint press-and-hold popovers and drives the add-friend confirm. Fixed the move-history "jump" bug (the slid board is now inert and the stage can't scroll, so a swipe up genuinely closes it). Menu.svelte + HoldConfirm.svelte removed.
  • No schema/wire change → no contour DB wipe. Bake-back: docs/UI_DESIGN.md, docs/FUNCTIONAL.md (+_ru). Regression gate: UI check + unit (tapconfirm) + build + bundle budget + e2e (Chromium & WebKit), all green.

• UI — Merge Exchange/Pass; drop the dead Tournaments tab (owner ad-hoc, not on the raw TODO list): the lobby's 🏆 Tournaments tab was an inert lobby.soon toast — removed (the lobby is back to three tabs, matching docs/FUNCTIONAL.md). In-game the separate 🥺 Skip (pass) tab folds into the 🔄 tab, now Exchange/Pass, whose dialog passes when no tile is selected and exchanges when tiles are.

  • Decision — a pass is NOT an exchange of zero (verified against the rules + GCG): the merge is UI-only. Pass and exchange stay distinct game actions end-to-end — wire (GameActionRequest vs ExchangeRequest), engine (ActionPass vs ActionExchange), and the GCG Poslfit dialect (a pass is a bare -, an exchange is -TILES). The engine forbids a zero-tile exchange (ErrNothingToExchange) and allows an exchange only with a full rack left in the bag (ErrNotEnoughTilesToExchange), while a pass is always legal — collapsing them would lose a real distinction. The dialog dispatches the existing gateway.pass / gateway.exchange.
  • What shipped: Lobby.svelte (tab removed); Game.svelte (one 🔄 Exchange/Pass tab no longer gated on an empty bag; the dialog disables tile selection while the bag is below a full rack (bagLen >= RACK_SIZE), its confirm button reading Pass without exchanging / Exchange N); i18n (game.draw → Exchange/Pass, new game.passNoExchange, dropped game.skip / lobby.tournaments / lobby.soon). No backend/wire/history/GCG change.
  • No schema/wire change → no contour DB wipe. Bake-back: docs/UI_DESIGN.md, docs/FUNCTIONAL.md (+_ru). Regression gate: UI check + unit + build + bundle budget + e2e (Chromium & WebKit).

• AI — Honest AI opponent in quick game (owner ad-hoc, not on the raw TODO list): a second quick-game opponent the player knowingly chooses, distinct from the disguised robot of the random/open path (which is kept as-is). New Game's quick-game mode replaces the "auto-match" subtitle with a two-button selector 🤖 AI / 👤 Random player (the .seg/.opt segmented style, AI the default); for AI the move-clock line reads "Loss after 7 days of inactivity" and the "searching" hint is hidden.

  • Locked decisions (interview): AI move is event-driven (the robot replies the instant the player's move commits; the 30 s driver is the fallback); AI games do not touch account_stats (practice, like guests); the Stage 5 strength logic is reused unchanged (playToWin 40 % from the seed + margin band); no per-move timeout — a 7-day inactivity loss instead; the 7-day line lives on the New Game screen (the in-game screen has no move-clock line); chat + nudge disabled, word-check kept, add-friend never drawn, opponent shown as 🤖 everywhere.
  • The 7-day rule reuses the existing per-turn timeout: an AI game is created with turn_timeout_secs = AIInactivityTimeout (7 days) and the existing timeout sweeper resigns the overdue seat — since the robot moves at once, only the human is ever on the clock, so the per-turn timeout is the abandon rule (no new column, no new sweeper).
  • One game flag drives everything: games.vs_ai (edited into the R1 baseline — pre-release, so a contour DB wipe after merge). It is set only on AI-started games, so a robot-filled random game keeps vs_ai=false and the disguised opponent is never revealed; the UI derives 🤖 / the gates from the flag, never from the opponent account. New backend path Matchmaker.StartVsAI (picks a pooled robot via the existing Pick, creates an active seated game via game.Service.Create, random seat order) — the AI request never enters the open pool, so the open-game reaper never touches it. The robot driver gains a vs_ai branch (no sleep, no proactive nudge, zero delay) and a focused DriveGame/TriggerMove fast path wired from the game service's after-create/after-commit hook (SetAITrigger, a func value so the game package never imports the robot package). Chat/nudge gated by a new social VsAI check (ErrGameVsAI → 409 ai_game); statistics skipped in commit when vs_ai.
  • Wire: EnqueueRequest += vs_ai, GameView += vs_ai (trailing FB fields, regenerated Go + TS), threaded through the backend DTO, the gateway transcode and the pkg/wire + notify builders.
  • Tests: lobby unit (StartVsAI seats a robot + flags the game; empty pool leaves no game); backend integration (ai_game_test.go: active+seated+vs_ai+7-day clock, robot moves immediately, stats skipped, 7-day timeout resigns the human, chat/nudge rejected); UI codec round-trip (vs_ai on enqueue + game view); e2e (an AI game shows 🤖, no "searching", chat disabled, the dictionary still works) + the existing quick-match e2e updated to pick Random player (the default is now AI).
  • Schema/wire change → a contour DB wipe after merge (DROP SCHEMA backend CASCADE + restart, the R1/R3 pattern). Bake-back: docs/ARCHITECTURE.md, docs/FUNCTIONAL.md (+_ru), docs/UI_DESIGN.md, backend/README.md, Go Doc comments.
  • Post-review refinements (owner, same PR): (1) the GCG export labels the robot seat "AI" rather than its human-like pool name (ExportGCG overrides the name via accounts.IsRobot; the in-app 🤖 is unchanged); (2) honest-AI games emit no your_turn — the robot replies instantly, so the signal would arrive with the move and be pointless; opponent_moved still advances the UI; (3) the admin console surfaces the AI flag — a 🤖 column in /games and an "AI game" line on the game card (GameRow/GameDetailView gain VsAI); (4) games_started_total / games_abandoned_total gain a vs_ai attribute and the Grafana Game domain dashboard splits started/abandoned into human and AI panels.
  • Follow-up (separate PR — strategy deviation): the robot now plays ≈20% of opening/midgame moves against its per-game playToWin intent (toward the opposite margin band — a winning robot eases off, a losing one surges ahead), tapering linearly to 0 over the last 14 bag tiles and 0 once the bag is empty, so the endgame follows the chosen strategy strictly while earlier outcomes can swing the human's way. Deterministic from the seed (mix(seed,"deviate",moveCount)), applied to both robot paths via the shared selectMove; the per-game intent (and the admin card) is unchanged. Tests: robot unit (taper bounds + monotonicity, never-in-endgame, determinism, ~20% distribution). Bake-back: docs/ARCHITECTURE.md §7, docs/FUNCTIONAL.md (+_ru), backend/README.md, PLAN.md Stage 5.

• GL — Simultaneous quick-game cap (owner ad-hoc, not on the raw TODO list): a player may hold at most 10 active quick games; at the cap the lobby greys New Game and shows a plain notice "Вы достигли лимита одновременных партий", both clearing automatically when an active game finishes.

  • Locked decisions (interview): what counts = active + open (searching) quick games, including AI (vs_ai); friend games (invitation-linked) never count. The backend gate refuses all new-game creation at the cap — lobby/enqueue and invitations — with 409 game_limit_reached; accepting an invitation is never gated, so friend games are capped "from the other end". Delivery = a boolean at_game_limit on the existing games.list (no per-event payload: a turn change does not move the count, and the lobby already re-fetches games.list on entry + every game event); the first uncached lobby frame defaults the button enabled (the backend gate is the authority).
  • What shipped: game.MaxActiveQuickGames + Store/Service.CountActiveQuickGames (active/open seats, no game_invitations row; hidden games still count → a dedicated count, not a filter over the lobby list); Server.atGameLimit/ensureUnderGameLimit gating handleEnqueue + handleCreateInvitation; gameListDTO.at_game_limit; the FB GameList trailing at_game_limit (regenerated Go + TS) threaded through the gateway transcode + UI codec; lib/model + lobbycache snapshot + Lobby.svelte (disabled tab + a muted .limit notice); i18n lobby.limitReached (en authoritative + ru).
  • Caveat (logged): the gate is a pre-check, not transaction-atomic — concurrent creates from one account could momentarily exceed by 1–2 (harmless soft cap; the UI disables the button regardless). Strict atomicity was judged a disproportionate diff across the two create paths.
  • No schema change → no contour DB wipe (only a trailing FB field, no migration). Tests: backend integration (game_limit_test.go: count rule + HTTP gate 409 + accept bypass), server unit (error mapping), gateway transcode round-trip, UI codec + lobbycache unit, e2e (gamelimit.spec.ts). Bake-back: docs/FUNCTIONAL.md (+_ru), docs/ARCHITECTURE.md §8, docs/UI_DESIGN.md, backend/README.md.