The hand-rolled scoring heuristic lost to a random-move baseline 7-7 in
self-play — far below the spec's >=80% acceptance bar. Swap in a real
chess engine (js-chess-engine, MIT, ~400KB, no native deps) for vanilla
mode at level 2 with randomness=30 to break threefold cycles.
- BrainInput.fen added; driver populates it ONLY in vanilla mode.
Blind mode omits the FEN so the engine path can't smuggle opponent
positions past the view filter.
- CasualBrain in vanilla: convert FEN -> EngineGame -> ai({level: 2});
validate the engine's move is in legalCandidates; fall back to
heuristic on miss.
- Blind mode unchanged (engine isn't useful when only own pieces are
visible — that's Phase 2 Recon's territory).
Self-play vs RandomBrain (100 games each direction, vanilla):
- Casual(W) vs Random(B): W=97%
- Random(W) vs Casual(B): B=96%
Casual-vs-Casual vanilla balanced, ~5-30ms/move. All 54 tests still pass.
Refresh .secrets.baseline (stale) to allow new pnpm-lock.yaml hashes.
Track aiOpponent in game store; show a pill badge in the topbar for AI
games, update turn label to "<Brain> is moving…" on the bot's turn,
and suppress the disconnected-opponent banner when the opponent is a bot.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- maybeAbandon Promise no longer floats from setTimeout
- broadcastSinceLast loses dead extra parameter
- bot-slot token is randomized so a third party can't hijack the
bot's color by guessing a fixed placeholder
Replace broadcastNewAnnouncements/broadcastUpdate with watermark-based
broadcastSinceLast; add pokeBot helper; make all state-mutating handlers
async; hook pokeBot after every mutation so the CasualBrain fires on
each turn without oracle access.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Extract endGame/finalizeIfEnded to game-end.ts so driver.ts can call
finalizeIfEnded after an applied move (fix: bot checkmate was not
setting game.status='finished'). Wrap entire dispatch() call in
try/catch for exception safety. Move lastSeenAnnouncementCount advance
to after successful dispatch so retry attempts see FSM rejection
announcements. Add checkmate-finalize test; lock retry-cap at 5 calls.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Wires Brain to Game: init/onStateChange/dispose lifecycle, in-flight
mutex, 5-attempt retry loop with attemptHistory, resign-on-cap. Also
adds Game.aiOpponent? field to state.ts for Task 5.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Svelte 5 $effect tracks every $state read inside its body. The
lifecycle effect that calls game.connect(gameId) implicitly read
state.ws (inside connect()) and then wrote to it, producing an
effect_update_depth_exceeded loop. Symptom in production: the
browser opened ~12 WS connections/sec, none completed the upgrade
handshake, and the lobby flow appeared stuck on 'waiting for
opponent' (the opponent's WS never stabilized long enough for the
server to send 'joined'). untrack() opts the call out of dep tracking.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Svelte 5 runes ($state, $derived, $effect) only run through the
compiler in .svelte and .svelte.ts/js files. A plain .ts file leaves
$state(...) as a literal call at runtime, causing
"ReferenceError: $state is not defined" and a blank page.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>