Gameplay (legal moves, move application, pressure maps, PGN parsing) now runs
entirely in the browser via a chess.js port of engine.py (static/engine.js +
vendored chess.min.js). The app no longer calls the server during play, so it
stays instant and works even when the backend is scaled to zero or offline.
- engine.js: line-for-line port of engine.py; parity-verified identical output
(pressure, FEN, status, SAN/UCI) across all 10 built-in games / 829 frames.
- app.js: replace all /api fetches with local engine calls; graceful PGN parse
errors; asset paths moved to root for static serving.
- Save games to localStorage + load from the game dropdown; export any game as
a .pgn file. Minimal additive UI in the existing export row.
- games.json generated from games.py (scripts/export_games.py).
- Production Dockerfile -> static-web-server (~9MB image, was ~150MB python).
- make dev -> bun static server; add make games / make parity targets.
- app.py kept as optional fallback (serves static app + /api routes).
- parity/: automated JS-vs-python engine parity test.
git diff stat:
16 files changed, 722 insertions(+), 128 deletions(-)
doMove only truncated moves/frames on the first divergence (forkPoint===null).
Subsequent rewind+move appended to the end of the line, corrupting the game
state irrecoverably. Always truncate to the current point before pushing.
Drop the dead forkedMoves state.
- btn-prev/next now use |◄ / ►| (single triangle + bar, was btn-start/end)
- btn-start/end now use |◄◄ / ►►| (double triangle + bar)
- playback-buttons row fills full width with flex:1 on all buttons
- outer two buttons (start/end) slightly smaller via flex:0.65 + 13px SVG
- All 5 playback buttons now use inline SVG triangles/bars — no more
emoji rendering on iOS/Android
- Pause icon in togglePlay() also switches to SVG
- Radio mode toggle becomes a segmented pill control (own row, full width)
- Piece/Board checkboxes each get their own tap-friendly row (min 2.5rem tall)
