fix: chess.js v0.10.3 API compat — use in_check/game_over/in_checkmate

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/js/modules/chess/logic/engine.js

@@ -21,13 +21,13 @@ export function moveUci(uci) {
 
 export function fen() { return game.fen(); }
 export function turn() { return game.turn(); }
-export function isGameOver() { return game.isGameOver(); }
-export function isCheckmate() { return game.isCheckmate(); }
-export function isDraw() { return game.isDraw(); }
-export function isStalemate() { return game.isStalemate(); }
-export function isCheck() { return game.isCheck(); }
-export function isThreefoldRepetition() { return game.isThreefoldRepetition(); }
-export function isInsufficientMaterial() { return game.isInsufficientMaterial(); }
+export function isGameOver() { return game.game_over ? game.game_over() : game.isGameOver(); }
+export function isCheckmate() { return game.in_checkmate ? game.in_checkmate() : game.isCheckmate(); }
+export function isDraw() { return game.in_draw ? game.in_draw() : game.isDraw(); }
+export function isStalemate() { return game.in_stalemate ? game.in_stalemate() : game.isStalemate(); }
+export function isCheck() { return game.in_check ? game.in_check() : game.isCheck(); }
+export function isThreefoldRepetition() { return game.in_threefold_repetition ? game.in_threefold_repetition() : game.isThreefoldRepetition(); }
+export function isInsufficientMaterial() { return game.insufficient_material ? game.insufficient_material() : game.isInsufficientMaterial(); }
 
 export function legalMoves(square) {
   return game.moves({ square, verbose: true });