fix(multiplayer): promote accepted matches atomically

multiplayer-next.md

@@ -1206,7 +1206,7 @@ production fallback.
 | 8.15 `[D:7.8,8.3]` | **IN PROGRESS.** Pure Go probe validation treats Steam location as opaque, requires nonce/freshness/region and server-computed RTT, and implements discrepancy quarantine/release; authenticated HTTP now accepts only opaque location/nonce input through a server-owned probe provider and records validated RTT into the active player's durable queue ticket; durable queue projections have a server-derived RTT JSON field for matcher reads | `server/domain/probes.go`, `server/migrations/0003_queue_probe_metadata.sql`, adversarial fixtures and `server/api/service.go`/`store/queue_sql.go` cover stale/wrong/forged evidence, the 25 ms/30% threshold, three-sample quarantine, five-clean release, authenticated provider arguments, rejection of client RTT fields, player/ticket/expiry binding, persistence failure, playlist-scoped candidate reads and bounded metadata decoding; Steam coordinator, regional probe adapters and multi-region probe population remain |
 | 8.16 `[D:8.14,8.15]` | **IN PROGRESS.** Pure Go candidate/team selection implements the <=100 ms ceiling, pairwise widening tolerance, anchor inclusion, deterministic set/region scoring and balanced team partitioning; queue-backed formation now consumes the server-owned projection, fences duplicate player identities and rejects playlist/build/protocol mixing; the matcher worker performs bounded formation and delegates the final claim to the durable proposal transaction; the runnable matcher now supports explicitly enabled ranked six-player polling with durable verified-Steam identity lookup. **Fixed a real crash-loop**: `Worker.Run` treated every `RunOnce` error as fatal to the whole loop, including "no compatible candidates" (`FormFromQueue`'s completely routine answer when currently-queued players share no verified region) — found building a live two-player integration attempt (see below): two real players with no common region crashed the entire matcher process, taking matchmaking down for every other player in the playlist, and would crash-loop again on restart since the same incompatible candidates stay queued. Now only genuine static misconfiguration (`ErrWorkerNotConfigured`/`ErrUnsupportedPlaylist`/`ErrInvalidMatcherSize`) stops the loop; everything else retries next interval | `server/domain/matcher.go`, `teams.go`, `server/matcher/worker.go`, `server/store/queue_sql.go` and adversarial fixtures cover no-common-region, tolerance boundaries, lexical ties, mean-rating balance, malformed candidates, duplicate identities, compatibility mismatches, incomplete batches, source failure, durable claim failure, queue-backed oldest-anchor formation and incomplete ranked identity metadata; two new tests cover `Run` (not just `RunOnce`) surviving a per-pass error via a real concurrent goroutine, and still stopping immediately on a real configuration error, both clean across repeated `-race` runs. **A live two-player Godot proposal integration attempt is on disk but not committed**: `Game/tests/control_plane_proposal_smoke.gd`/`.tscn` and `scripts/verify_control_plane_proposal_integration.sh` exist and found the bug above, but the session paused running further concurrent headless Godot processes after discovering they'd been causing native engine crashes (macOS crash reporter, `EXC_BAD_ACCESS`/`SIGBUS`) intermittently all session, confirmed by the user; the two-player script was never itself verified to a clean pass. Arena selection and long-running worker integration remain |
 | 8.17 `[D:8.14,8.16]` | **IN PROGRESS.** Pure Go proposal policy sends a 10-second response window to every selected human, requires unanimous acceptance, applies exact casual/ranked decline and timeout cooldowns with ranked escalation, and exposes revisioned idempotent responses through the authenticated API. Proposal closure now atomically separates offenders from innocents: a decliner's ticket is `CANCELLED`; a timed-out player's ticket is `EXPIRED`; accepted or otherwise innocent participants return to `QUEUED` with their original `enqueued_at` and refreshed expiry. Direct queue cancellation closes the open proposal and requeues remaining participants immediately. Late API responses commit expiry, timeout penalties, and ticket release before returning `ErrProposalClosed`; recovery of an old declined proposal cannot misclassify its pending innocents as timeouts. Cooldown history rejects future, foreign-playlist, and invalid-kind events, and database rows are closed before penalty writes | Domain/store/API fixtures cover partial/unanimous response, expiry, replay/conflict, stale revision, exact cooldown windows/escalation, corrupt history filtering, offender ticket termination, innocent precedence preservation, direct-cancel cascade, and the former late-response rollback. PostgreSQL-tagged regressions compile and assert the durable split and penalty rows; the full local Go suite passes. Live PostgreSQL execution and allocation integration remain |
-| 8.18 `[D:8.5,8.14,8.17]` | **IN PROGRESS.** Go store layer defines PostgreSQL SERIALIZABLE whole-transaction retries and queue candidate/proposal claim SQL using `FOR UPDATE SKIP LOCKED` plus durable uniqueness/revision fences; proposal creation persists matcher-selected region/protocol/team/slot topology before acceptance, and final unanimous acceptance promotes the exact roster into one `ALLOCATING` match. Promotion replay validates immutable playlist/region/protocol/arena, participant, ticket, team, and slot identity but deliberately ignores mutable match state/server ownership, so a retry after a lost response still succeeds after allocation has advanced. Result sets are closed before crossing into promotion writes, avoiding one-connection pool stalls. Redis remains a rebuildable candidate projection over PostgreSQL authority | Store/API tests cover retries, claims, owner/revision fencing, expiry, exact promotion replay/conflict, progressed-match replay, rollback of partial claims, concurrent contested-ticket formation, and lost-cache repair. PostgreSQL-tagged regressions compile; prior live runs covered queue/proposal promotion and races, while this progressed-replay change awaits a live database rerun. Allocation runtime integration remains |
+| 8.18 `[D:8.5,8.14,8.17]` | **IN PROGRESS.** Go store layer defines PostgreSQL SERIALIZABLE whole-transaction retries and queue candidate/proposal claim SQL using `FOR UPDATE SKIP LOCKED` plus durable uniqueness/revision fences; proposal creation persists matcher-selected region/protocol/team/slot topology before acceptance, and the same serializable final-acceptance transaction now promotes the exact roster into one `ALLOCATING` match, closing the process-crash gap that could otherwise strand an accepted proposal before the former second promotion transaction. The API promoter remains a replay check. Promotion replay validates immutable playlist/region/protocol/arena, participant, ticket, team, and slot identity but deliberately ignores mutable match state/server ownership, so a retry after a lost response still succeeds after allocation has advanced. Result sets are closed before crossing into promotion writes, avoiding one-connection pool stalls. Redis remains a rebuildable candidate projection over PostgreSQL authority | Store/API tests cover retries, claims, owner/revision fencing, expiry, exact promotion replay/conflict, progressed-match replay, rollback of partial claims, concurrent contested-ticket formation, and lost-cache repair. PostgreSQL-tagged regressions compile and assert acceptance, ticket transitions, match creation, and roster insertion are one durable outcome; prior live runs covered queue/proposal promotion and races, while this atomic-promotion change awaits a live database rerun. Allocation runtime integration remains |
 | 8.19 `[D:8.18]` | **IN PROGRESS.** Pure Go casual lineup requires 2–6 humans with at least one per team, fills missing slots with explicit bots, permits kickoff-only bot-slot backfill and assigns no backfill penalty/rating update; proposal preparation now derives the lineup from formed teams | `server/domain/casual.go`, `formation.go` cover both-team minimum, bot shape, live-play rejection, zero-penalty backfill and casual proposal composition; queue candidate selection, opt-in 10 s backfill proposals, reconnect/leave penalties and live integration remain |
 | 8.20 `[D:8.18]` | **IN PROGRESS.** Pure Go ranked admission requires six unique verified solo humans, rejects bots/backfill/parties, and allows only random-enabled non-elevated arenas; proposal preparation requires matching metadata for every formed player | `server/domain/ranked.go`, `formation.go` cover count, identity, party, bot/backfill, arena eligibility and formed-player metadata rejection; `ArenaRegistry` integration, allocation wiring and innocent-ticket restoration remain |
 | 8.21 `[D:8.5,8.20]` | **IN PROGRESS.** Pure Go rating core implements canonical Glicko-2, daily inactivity, ranked 1/3 and casual 1/N human-opponent weights, deterministic opponent ordering, and authoritative draw/overtime/abandon scoring; certified result completion now applies per-player updates inside the durable transaction with lexical row locks and revision increments | `server/domain/rating.go`, `server/store/result_sql.go` and tests cover canonical/inactivity/weight/invalid-input, draw/OT/abandon, ordered participant snapshots, lock/value re-read and rating update SQL; live PostgreSQL rating and seasons execution now covered (§8.23), and concurrent result transaction cases are covered: `TestPostgreSQLConcurrentIdenticalResultSubmissionAppliesRatingsExactlyOnce` races 5 identical submissions and confirms one rating application, while `TestPostgreSQLConcurrentConflictingResultSubmissionsKeepOneReceipt` races different payloads and confirms exactly one winner, one conflict, one receipt and one completion event; live maintenance/DB execution remains |