fix: chess pieces now ACTUALLY animate — call board.animateMove() before setPosition

The animateMove method existed on the board but was never called.
Game scene was still doing board.setPosition() instantly.

Fixed:
- Player moves: animateMove(from, to) → piece slides 200ms → then setPosition
- Bot moves: same — piece slides smoothly before board updates
- Initial position: stays instant (correct — no animation needed on load)

The animation method uses requestAnimationFrame to interpolate piece
position linearly from source square to destination over 200ms.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

public/js/modules/chess/scenes/game.js

@@ -280,8 +280,11 @@ function executeMove(el, from, to, promotion) {
   if (!m) return;
 
   gameState.moveCount++;
-  board.setPosition(engine.fen());
-  board.setLastMove(from, to);
+  // Animate piece sliding from → to, THEN update board state
+  board.animateMove(from, to, () => {
+    board.setPosition(engine.fen());
+    board.setLastMove(from, to);
+  });
 
   // Sound + Juice
   if (m.san.includes('#')) {
@@ -374,8 +377,11 @@ async function requestBotMove(el) {
 
       const m = engine.move(from, to, promo);
       if (m) {
-        board.setPosition(engine.fen());
-        board.setLastMove(from, to);
+        // Animate bot's piece sliding smoothly
+        board.animateMove(from, to, () => {
+          board.setPosition(engine.fen());
+          board.setLastMove(from, to);
+        });
 
         if (m.san.includes('#')) audio.play('gameOver', 'game');
         else if (m.san.includes('+')) audio.play('check', 'game');