- Record moves in standard algebraic notation (GameState.SanHistory), built at
move time in ChessService (captures, disambiguation, castling, promotion,
en passant, and the check/mate suffix)
- Add PgnExporter.ToPgn (seven-tag header + movetext + result) and a
GET /api/chess/{gameId}/pgn endpoint
- Show a Copy PGN button when a game ends on both the play and watch pages,
prefetching the PGN so it works during the post-game cleanup window
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
