# US-09 — Drop out and come back mid-round

**As a** player on flaky Wi-Fi (or a locked laptop),
**I want to** reconnect and land back in the same kitchen mid-round,
**so that** one dropped socket does not ruin the group's game.

## Acceptance criteria
1. Losing the socket keeps the player's seat for `GUEST_IDLE_TIMEOUT_S` (default 45 s);
   the cook stays in the kitchen and, after 3 s idle, parks and drops what they carried.
2. The other players see a "Cookie disconnected" label, not a vanished cook.
3. Reconnecting with the same token + code mid-round restores the seat and resumes
   snapshots; time-to-playable ≤ 3 s after page load.
4. The client shows a "reconnecting…" overlay with exponential backoff (0.5 s → 8 s cap,
   jittered) and never spams the server.
5. Reconnecting after the grace window releases the seat and the player re-enters as a
   spectator (or joins the lobby if one exists).
6. The server never leaves a ghost connection: a second socket for a token evicts the
   first, and closed rooms reject stale tokens with a clean error.
7. A room whose last seat is gone is closed and its resources freed within one GC cycle.
8. A mid-round server-side room exception aborts only that room and tells its players.

## E2E suite
`tests/e2e/test_us09_disconnect_rejoin.py` — kill the socket (context.close of page B /
server-side `kill_connection` test hook), assert ghost label, reload and rejoin mid-round,
assert playable ≤ 3 s and identical score. Integration: seat grace, GC, stale-token paths.

## Phases
`06_realtime_websocket_protocol`, `08_client_prediction_and_touch`,
`12_reconnect_resilience_and_scale`