fix(chess): migrate ChessBoard to react-chessboard v5 API

react-chessboard v5 moved all props into an `options` object and
renamed several callbacks/style props. The v4-style props were silently
ignored, causing pieces to snap back, no legal-move highlights, and no
WS events on drop. Also adds a custom promotion dialog since v5 removed
the built-in one.

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

panel/src/games/chess/ChessBoard.tsx

@@ -325,7 +325,8 @@ export function ChessBoard({ state, myPlayerId, isSpectator, onAction, players }
         onAction({ type: "move", from, to, ...(promotion ? { promotion } : {}) });
     }
 
-    function onDrop(sourceSquare: string, targetSquare: string): boolean {
+    function onDrop({ sourceSquare, targetSquare }: { piece: any; sourceSquare: string; targetSquare: string | null }): boolean {
+        if (!targetSquare) return false;
         if (isSpectator || !isMyTurn || isGameOver) return false;
         const testGame = new Chess(localFenRef.current);
         const piece = testGame.get(sourceSquare as any);
@@ -347,15 +348,13 @@ export function ChessBoard({ state, myPlayerId, isSpectator, onAction, players }
 
     function handlePromotion(piece: string) {
         if (promotionFrom && promotionTo) {
-            const promotionPiece = piece[1]?.toLowerCase() ?? "q";
+            dispatchMove(promotionFrom, promotionTo, piece);
-            dispatchMove(promotionFrom, promotionTo, promotionPiece);
         }
         setPromotionFrom(null);
         setPromotionTo(null);
-        return true;
     }
 
-    function onSquareClick(square: string) {
+    function onSquareClick({ square }: { piece: any; square: string }) {
         if (isSpectator || isGameOver || !isMyTurn) return;
         if (promotionFrom !== null) return;
         const testGame = new Chess(localFenRef.current);
@@ -397,9 +396,9 @@ export function ChessBoard({ state, myPlayerId, isSpectator, onAction, players }
         if (isBothSides ? color === turn : color === myColor) setSelectedSquare(square);
     }
 
-    function isDraggablePiece({ piece }: { piece: string }): boolean {
+    function canDragPiece({ piece }: { isSparePiece: boolean; piece: { pieceType: string }; square: string | null }): boolean {
         if (isSpectator || !isMyTurn || isGameOver) return false;
-        const pieceColor = piece[0] === "w" ? "white" : "black";
+        const pieceColor = piece.pieceType === piece.pieceType.toUpperCase() ? "white" : "black";
         return isBothSides ? pieceColor === turn : pieceColor === myColor;
     }
 
@@ -472,26 +471,41 @@ export function ChessBoard({ state, myPlayerId, isSpectator, onAction, players }
                 />
 
                 {/* Board wrapper */}
-                <div ref={containerRef} className="relative" style={{ lineHeight: 0 }}>
+                <div ref={containerRef} className="relative" style={{ lineHeight: 0, width: boardWidth, maxWidth: "100%" }}>
                     <Chessboard
-                        position={localFen}
+                        options={{
-                        onPieceDrop={onDrop}
+                            position: localFen,
-                        onPromotionPieceSelect={handlePromotion}
+                            onPieceDrop: onDrop,
-                        onSquareClick={onSquareClick}
+                            onSquareClick: onSquareClick,
-                        boardOrientation={boardOrientation}
+                            boardOrientation: boardOrientation,
-                        isDraggablePiece={isDraggablePiece}
+                            canDragPiece: canDragPiece,
-                        boardWidth={boardWidth}
+                            animationDurationInMs: 150,
-                        showPromotionDialog={promotionFrom !== null}
+                            squareStyles: customSquareStyles,
-                        promotionToSquare={promotionTo as any}
+                            darkSquareStyle: { backgroundColor: DARK_SQUARE },
-                        animationDuration={150}
+                            lightSquareStyle: { backgroundColor: LIGHT_SQUARE },
-                        customSquareStyles={customSquareStyles}
+                            boardStyle: { borderRadius: "0" },
-                        customDarkSquareStyle={{ backgroundColor: DARK_SQUARE }}
+                            dropSquareStyle: { boxShadow: "inset 0 0 1px 6px rgba(20,85,30,0.7)" },
-                        customLightSquareStyle={{ backgroundColor: LIGHT_SQUARE }}
+                        }}
-                        customBoardStyle={{ borderRadius: "0" }}
-                        customDropSquareStyle={{ boxShadow: "inset 0 0 1px 6px rgba(20,85,30,0.7)" }}
-                        customPremoveDarkSquareStyle={{ backgroundColor: "#a04a4a" }}
-                        customPremoveLightSquareStyle={{ backgroundColor: "#d08080" }}
                     />
+                    {promotionFrom !== null && (
+                        <div
+                            className="absolute inset-0 flex items-center justify-center z-20"
+                            style={{ backgroundColor: "rgba(20, 18, 15, 0.7)" }}
+                        >
+                            <div className="flex gap-1 p-2 rounded-lg" style={{ backgroundColor: "#1a1917", border: "1px solid #3a3733" }}>
+                                {["q", "r", "b", "n"].map((p) => (
+                                    <button
+                                        key={p}
+                                        onClick={() => handlePromotion(p)}
+                                        className="w-12 h-12 flex items-center justify-center text-2xl rounded hover:bg-white/10 transition-colors"
+                                        style={{ color: "#f0d9b5" }}
+                                    >
+                                        {{ q: turn === "white" ? "♕" : "♛", r: turn === "white" ? "♖" : "♜", b: turn === "white" ? "♗" : "♝", n: turn === "white" ? "♘" : "♞" }[p]}
+                                    </button>
+                                ))}
+                            </div>
+                        </div>
+                    )}
                     {isGameOver && (
                         <GameOverOverlay
                             status={chess.status}