feat: publish assignment rosters atomically

multiplayer-todo.md

@@ -1228,7 +1228,7 @@ the local/CI/community transport, not a silent production fallback.
 |---|---|---|
 | 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 publishes targeted authenticated revisioned queue/proposal/assignment events and the Godot client consumes state/proposal/assignment events, fetching the authoritative assignment after assignment readiness; the API can now use the durable participant-scoped proposal provider for both recovery and accept/decline mutations | `test_matchmaking_state.gd`, `test_control_plane_client.gd`, `test_matchmaking_ui.gd`, `TestProposalRecoveryIsParticipantScopedAndExpiresAtReadBoundary`, `TestAuthenticatedWebSocketDeliversOnlyTargetedRevisionedEvents`, `TestStateChangingAPIActionsPublishTargetedEvents`, `TestProposalRecoveryUsesDurableBackendAndRemainsParticipantScoped` and store proposal SQL tests 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/vocabulary 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, exactly-once slow-subscriber closure and invalid-event rejection; 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; migration 0002 and the Go store adapter now persist/recover the complete player-scoped assignment projection with conflict-safe identical replay; `AssignmentProviderFromStore` wires that durable projection into the API injection point | `server/api/service.go`, `store_adapters.go`, `service_test.go`, `assignment_state.gd`, `test_assignment_state.gd`, `server/migrations/0002_assignments.sql` and `server/store/assignment_sql.go` cover participant/identity/expiry/shape/transport boundaries, player-scoped schema keys, expiry-filtered reads, assignment upsert conflict handling and nil-store fail-closed behavior; signed manifest-to-player persistence wiring, SDR relay-ticket installation, `hello` join-authorisation wiring, fencing integration and live Godot/PostgreSQL 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; migration 0002 and the Go store adapter now persist/recover the complete player-scoped assignment projection with conflict-safe identical replay; `AssignmentProviderFromStore` wires that durable projection into the API injection point; `SaveAssignments` publishes a complete signed roster atomically instead of allowing partial player visibility | `server/api/service.go`, `store_adapters.go`, `service_test.go`, `assignment_state.gd`, `test_assignment_state.gd`, `server/migrations/0002_assignments.sql` and `server/store/assignment_sql.go` cover participant/identity/expiry/shape/transport boundaries, player-scoped schema keys, expiry-filtered reads, assignment upsert conflict handling, atomic batch validation and nil-store fail-closed behavior; signed manifest-to-player caller wiring, SDR relay-ticket installation, `hello` join-authorisation wiring, fencing integration and live Godot/PostgreSQL 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 |
 

server/store/assignment_sql.go

@@ -86,6 +86,44 @@ func SaveAssignment(ctx context.Context, db *sql.DB, assignment DurableAssignmen
 	return nil
 }
 
+// SaveAssignments publishes a complete signed roster atomically. Assignment
+// readiness is a match boundary: exposing only some players would let the
+// control plane tell different participants incompatible stories after a
+// transient database failure.
+func SaveAssignments(ctx context.Context, db *sql.DB, assignments []DurableAssignment) error {
+	if db == nil || len(assignments) == 0 {
+		return fmt.Errorf("invalid assignment batch")
+	}
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	seen := make(map[string]struct{}, len(assignments))
+	for _, assignment := range assignments {
+		if err := validateDurableAssignment(assignment); err != nil {
+			return err
+		}
+		key := assignment.MatchID + "\x00" + assignment.PlayerID
+		if _, ok := seen[key]; ok {
+			return fmt.Errorf("duplicate assignment in batch")
+		}
+		seen[key] = struct{}{}
+		result, err := tx.ExecContext(ctx, AssignmentUpsertSQL, assignment.MatchID, assignment.PlayerID, assignment.AllocationID, assignment.ServerID, assignment.Slot, assignment.Region, assignment.ClientBuild, assignment.ProtocolVersion, assignment.Transport, assignment.Endpoint, assignment.JoinAuthorisation, assignment.ManifestDigest, assignment.ExpiresAt, assignment.Revision)
+		if err != nil {
+			return err
+		}
+		changed, err := result.RowsAffected()
+		if err != nil {
+			return err
+		}
+		if changed != 1 {
+			return fmt.Errorf("assignment persistence conflict")
+		}
+	}
+	return tx.Commit()
+}
+
 func GetAssignment(ctx context.Context, db *sql.DB, playerID, matchID string, now time.Time) (DurableAssignment, error) {
 	if db == nil || playerID == "" || matchID == "" || now.IsZero() {
 		return DurableAssignment{}, fmt.Errorf("invalid assignment recovery arguments")

server/store/assignment_sql_test.go

@@ -29,3 +29,12 @@ func TestAssignmentStoreRejectsInvalidRecoveryAndManifestInputs(t *testing.T) {
 		t.Fatal("out-of-range slot accepted")
 	}
 }
+
+func TestAssignmentStoreRejectsInvalidBatches(t *testing.T) {
+	if err := SaveAssignments(nil, nil, nil); err == nil {
+		t.Fatal("nil database/empty batch accepted")
+	}
+	if err := SaveAssignments(nil, nil, []DurableAssignment{{MatchID: "match-1", PlayerID: "player-1"}}); err == nil {
+		t.Fatal("invalid assignment batch accepted")
+	}
+}