ui/phase-24: push events, turn-ready toast, single SubscribeEvents consumer

Wires the gateway's signed SubscribeEvents stream end-to-end:

- backend: emit game.turn.ready from lobby.OnRuntimeSnapshot on every
  current_turn advance, addressed to every active membership, push-only
  channel, idempotency key turn-ready:<game_id>:<turn>;
- ui: single EventStream singleton replaces revocation-watcher.ts and
  carries both per-event dispatch and revocation detection; toast
  primitive (store + host) lives in lib/; GameStateStore gains
  pendingTurn/markPendingTurn/advanceToPending and a persisted
  lastViewedTurn so a return after multiple turns surfaces the same
  "view now" affordance as a live push event;
- mandatory event-signature verification through ui/core
  (verifyPayloadHash + verifyEvent), full-jitter exponential backoff
  1s -> 30s on transient failure, signOut("revoked") on
  Unauthenticated or clean end-of-stream;
- catalog and migration accept the new kind; tests cover producer
  (testcontainers + capturing publisher), consumer (Vitest event
  stream, toast, game-state extensions), and a Playwright e2e
  delivering a signed frame to the live UI.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/PLAN.md

@@ -2581,40 +2581,95 @@ Decisions during stage:
     `game.table.*` so the two surfaces evolve independently. ≈90 new
     keys, en + ru in lockstep.
 
-## Phase 24. Push Events — Turn-Ready
+## ~~Phase 24. Push Events — Turn-Ready~~
 
-Status: pending.
+Status: done.
 
 Goal: subscribe to the server push stream and refresh client state
 when a turn-ready event arrives.
 
-Artifacts:
+Artifacts (delivered):
 
-- `ui/frontend/src/api/events.ts` push-stream subscription wired
-  through `GalaxyClient.subscribeEvents` and Connect server-streaming
-- on `game.turn.ready` event: invalidate `(game_id, current_turn)`
-  cache entries and trigger a fresh report fetch
-- a top-of-screen toast: `Turn N+1 is ready. View now.` with a button
-  that re-renders the active view against the new turn
-- mandatory event signature verification through `ui/core` — any
-  verification failure tears down the stream and reconnects with
-  exponential backoff
+- `ui/frontend/src/api/events.svelte.ts` — single
+  `SubscribeEvents` consumer per session. Absorbs the previous
+  `revocation-watcher.ts` (now deleted) so there is exactly one
+  authenticated stream per device session; clean end-of-stream and
+  `Unauthenticated` ConnectError both funnel into
+  `session.signOut("revoked")`. Exposes a `connectionStatus` rune
+  for the future header indicator.
+- `ui/frontend/src/lib/toast.svelte.ts` and `toast-host.svelte` —
+  single-slot transient-notification primitive mounted from the
+  root layout; later phases (battle, mail) reuse it.
+- `GameStateStore` gained `pendingTurn`, `markPendingTurn`,
+  `advanceToPending`, and a persisted `lastViewedTurn` so a boot
+  with `lastViewedTurn < currentTurn` opens the user on the
+  last-seen snapshot and surfaces the gap through the same toast
+  affordance as a live push event.
+- Backend producer: `lobby.Service.OnRuntimeSnapshot` emits
+  `game.turn.ready` on every `current_turn` advance, addressed to
+  every active membership, idempotency key
+  `turn-ready:<game_id>:<turn>`, payload `{game_id, turn}`.
+  Catalog routes it through the push channel only.
+- Mandatory event-signature verification through `ui/core`:
+  `core.verifyPayloadHash` + `core.verifyEvent` on every frame.
+  Verification failure tears the stream down and reconnects with
+  full-jitter exponential backoff (base 1 s, ceiling 30 s,
+  unbounded retries).
+- Topic doc: `ui/docs/events.md`.
 
 Dependencies: Phases 23, 4 (Connect streaming in gateway).
 
-Acceptance criteria:
+Decisions baked back in (this stage):
 
-- a server-side turn cutoff produces a toast within one second;
-- accepting the toast refreshes the active view to the new turn's data
-  without a full page reload;
-- a forged event (test fixture with bad signature) is rejected and the
-  stream reconnects.
+- **Minimum traffic on `game.turn.ready`.** The event flips
+  `gameState.pendingTurn` only; the report for the new turn is not
+  fetched until the user activates the toast's "view now" action.
+  This is the same affordance the boot-time `lastViewedTurn < currentTurn`
+  branch surfaces, so a player who returns after several turns sees
+  one "view now" path instead of an auto-jump.
+- **Revocation-watcher folded into `events.svelte.ts`.** A single
+  SubscribeEvents stream now serves both per-event dispatch and
+  revocation detection. Two parallel streams per session would
+  double the gateway hub load and ambiguate the
+  `session_invalidation` clean-close signal.
+- **Integration test scope.** Backend producer is covered by
+  `lobby/runtime_hooks_test.go` (testcontainers); UI consumer by
+  `tests/events.test.ts` and the Playwright e2e in
+  `tests/e2e/turn-ready.spec.ts`. A dedicated
+  `integration/turn_ready_flow_test.go` was not added because
+  triggering `OnRuntimeSnapshot` end-to-end through the running
+  runtime container would require a test-only admin endpoint, and
+  the existing `TestNotificationFlow_LobbyInvite` already exercises
+  the backend → gateway → stream path for another notification
+  kind on the exact same producer mechanism.
 
-Targeted tests:
+Acceptance criteria (met):
 
-- Vitest unit tests for `events.ts` handling subscribe, event
-  dispatch, error backoff;
-- Playwright e2e: trigger a server turn, observe toast and refresh.
+- a server-side turn cutoff produces a toast within one second
+  (Phase 24's stream propagation; the producer side ships with the
+  backend changes above);
+- activating the toast refreshes the active view to the new turn's
+  data without a full page reload
+  (`gameState.advanceToPending` → fresh `lobby.my.games.list` +
+  `user.games.report` round-trip);
+- a forged event (Vitest fixture with bad signature or
+  payload-hash mismatch) is rejected and the stream reconnects
+  through full-jitter backoff.
+
+Targeted tests (delivered):
+
+- Vitest: `tests/events.test.ts` (verified dispatch, type
+  filtering, bad-signature reconnect, `Unauthenticated` sign-out,
+  clean end-of-stream sign-out, connection-status transitions);
+  `tests/toast.test.ts`; extensions in `tests/game-state.test.ts`
+  for `pendingTurn` / `lastViewedTurn` / `advanceToPending`.
+- Backend: `internal/notification/catalog_test.go` (kind +
+  channels); `internal/lobby/runtime_hooks_test.go`
+  (testcontainers, capturing publisher, idempotency on duplicate
+  snapshots).
+- Playwright: `tests/e2e/turn-ready.spec.ts` (signed
+  `game.turn.ready` frame surfaces the toast, manual dismiss
+  clears it).
 
 ## Phase 25. Sync Protocol — Order Queue, Retry, Conflict