fix: close slow event subscribers safely

multiplayer-todo.md

@@ -1227,7 +1227,7 @@ the local/CI/community transport, not a silent production fallback.
 | # | Task | Acceptance |
 |---|---|---|
 | 8.39 `[D:8.3,8.14,8.17]` | **IN PROGRESS.** `MatchmakingState` now projects queue → proposal → allocation/process-ready/assignment-ready/connect/live plus terminal failure states; autoload `ControlPlaneClient` provides authenticated queue create/recovery/heartbeat/cancel and proposal response requests with idempotency/revision headers; `matchmaking.tscn`/`matchmaking.gd` expose the state and authoritative actions from the main menu; authenticated proposal recovery now reconciles missed proposal events and expires them at read time; the Go API now provides targeted authenticated revisioned event publication and the Godot client consumes state/proposal events | `test_matchmaking_state.gd`, `test_control_plane_client.gd`, `test_matchmaking_ui.gd`, `TestProposalRecoveryIsParticipantScopedAndExpiresAtReadBoundary` and `TestAuthenticatedWebSocketDeliversOnlyTargetedRevisionedEvents` reject stale/gapped/conflicting updates, validate endpoint/token/payload normalization, preserve idempotent duplicates, and guarantee visible phase/terminal copy; wiring durable allocation events into the outbox, wait/latency explanations and Godot runtime verification remain |
-| 8.40 `[D:8.3,8.14]` | **IN PROGRESS.** Pure Go revisioned replica reducer rejects gaps for REST resync, makes duplicate/out-of-order events idempotent, and resumes from the authoritative snapshot revision; authenticated queue-ticket recovery now has an owner-checked REST read; Godot client projection persists non-secret ticket/proposal state, forces authoritative recovery after restart, and can replay a lost queue-create response with the original ticket/idempotency key; the Go API now exposes an authenticated `/v1/events` WebSocket with bounded per-player queues, strict upgrade validation and REST-resync-safe slow-client failure; Godot `ControlPlaneClient` can connect to the stream, consume validated events, automatically reconnect with bounded backoff, and trigger REST recovery on projection gaps and stream return | `server/domain/sync.go`, `server/api/events.go`, `server/api/service.go`, `service_test.go`, `matchmaking_state.gd` and `control_plane_client.gd` cover gap, snapshot, replay, same-revision conflict, owner-only ticket recovery, expired-ticket terminal handling, malformed restart snapshots, API-level duplicate-create replay/conflict, authenticated handshake/key rejection and targeted event delivery; durable outbox fan-out and live Godot verification remain |
+| 8.40 `[D:8.3,8.14]` | **IN PROGRESS.** Pure Go revisioned replica reducer rejects gaps for REST resync, makes duplicate/out-of-order events idempotent, and resumes from the authoritative snapshot revision; authenticated queue-ticket recovery now has an owner-checked REST read; Godot client projection persists non-secret ticket/proposal state, forces authoritative recovery after restart, and can replay a lost queue-create response with the original ticket/idempotency key; the Go API now exposes an authenticated `/v1/events` WebSocket with bounded per-player queues, strict upgrade validation and REST-resync-safe slow-client failure; Godot `ControlPlaneClient` can connect to the stream, consume validated events, automatically reconnect with bounded backoff, and trigger REST recovery on projection gaps and stream return | `server/domain/sync.go`, `server/api/events.go`, `server/api/service.go`, `service_test.go`, `matchmaking_state.gd` and `control_plane_client.gd` cover gap, snapshot, replay, same-revision conflict, owner-only ticket recovery, expired-ticket terminal handling, malformed restart snapshots, API-level duplicate-create replay/conflict, authenticated handshake/key rejection, targeted event delivery and exactly-once slow-subscriber closure; durable outbox fan-out and live Godot verification remain |
 | 8.41 `[D:7.8,8.9,8.31,8.40]` | **IN PROGRESS.** Authenticated `GET /v1/assignments/{matchId}` now exposes only a validated, player-scoped assignment view; Godot `AssignmentState`/`ControlPlaneClient.fetch_assignment()` bind the response to the authenticated player, recheck expiry, preserve explicit transport/slot/join authorisation and do not connect before assignment-ready | `server/api/service.go`, `service_test.go`, `assignment_state.gd` and `test_assignment_state.gd` cover participant/identity/expiry/shape/transport boundaries and assignment recovery; signed manifest-to-player persistence, SDR relay-ticket installation, `hello` join-authorisation wiring, fencing integration and live Godot verification remain |
 | 8.42 `[D:8.22,8.23,8.24,8.40]` | **IN PROGRESS.** `RankedProfileState` and `ControlPlaneClient.fetch_ranked_profile()` expose the backend-authoritative rating/RD/volatility/games/tier/provisional/season view; matchmaking UI displays provisional/tier status without client-side rating math | `test_control_plane_client.gd` validates profile shape, numeric safety and provisional display; ranked profile fetch/display, committed revision after reconnect, abandon status and season countdown remain dependent on live auth/backend events and Godot runtime verification |
 | 8.43 `[D:8.39,8.40,8.41]` | **IN PROGRESS.** Matchmaking client now distinguishes expired queue recovery, session expiry, missing records and retryable control-plane outages; a 401 clears the in-memory token, emits `session_expired` and disables retry until a new session is configured; terminal messages remain visible and active searches are not falsely failed on transient errors | `MatchmakingState` and `ControlPlaneClient` tests cover explicit expiry and the existing terminal/retry-safe state paths; decline, version mismatch, regional outage retry UI, failed reconnect, duplicate-action recovery and live Godot verification remain |