Closes the residual tail of the previous commit: when the live stream stays
alive across a brief suspend (Telegram/iOS can pause the socket without tearing
it down), an in-game event shed from a full hub buffer is never recovered by
the reconnect refetch (no reconnect) or the open-game poll (it only runs while
the stream is down). Mirror the lobby's focus re-poll: bump app.resync on a
foreground regain that did not drop the stream, and have Game.svelte refetch
the open game once per resync. Also rescues a missed move/game_over after a
suspend. Add a silent-join mock seam + an e2e isolating this path; extend the
ARCHITECTURE §10 fallback note.
PR #51 moved the auto-match "wait for an opponent" from the lobby matchmaking
screen into the open game but did not carry over that screen's poll fallback.
The notify hub is best-effort and never replays, the live-stream resubscribe
sends no cursor, and the game screen refreshed only from push events — so an
opponent_joined dropped while the stream was down (e.g. a mobile suspend) left
the starter stuck on "searching for opponent" until they re-entered the game.
Unlike opponent_moved/game_over, opponent_joined has no follow-up event to
trigger the existing move-count gap refetch.
Recover it in Game.svelte: (A) refetch once on stream reconnect (covers the
common suspend/resume case and rescues a missed move/game_over too), and
(B) poll game.state every 2.5s while still waiting with the stream down
(mirrors the old matchmaking startPoll). Add a mock-mode __stream e2e seam and
two specs isolating each path, fix the now-stale streamAlive comment, and
document the fallback in ARCHITECTURE §10.
Ilia Denisov