feat(chess): polish UI with SVG pieces, motion animations, sound, and confetti

- Add Cburnett SVG chess pieces from Wikimedia (Lichess set, ~18KB total)
- Add move/capture/check/checkmate/castle/promote sound effects via OGG
- Install motion for layout animations: pieces slide smoothly, captures fade
- Install canvas-confetti: victory celebration on checkmate
- Install sonner: toast notifications
- Install lucide-react: volume icons for mute toggle
- Persist mute state in localStorage
- Animated game-over banner (spring entrance)
- Animated drawer slide-in replacing CSS keyframe
- Lobby and App get polished visual treatment
- Preserve all E2E data-* selectors and drag-drop contract

Co-authored-by: visual-engineering agent

packages/chess/package.json

@@ -16,15 +16,20 @@
   "dependencies": {
     "@paratype/rete": "workspace:*",
     "@tailwindcss/vite": "^4.2.2",
+    "canvas-confetti": "^1.9.4",
+    "lucide-react": "^1.8.0",
+    "motion": "^12.38.0",
     "react-router-dom": "^7.14.1",
+    "sonner": "^2.0.7",
     "tailwindcss": "^4.2.2"
   },
   "devDependencies": {
-    "vite": "^6.0.0",
+    "@types/canvas-confetti": "^1.9.0",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
     "@vitejs/plugin-react": "^4.0.0",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
-    "@types/react": "^19.0.0",
-    "@types/react-dom": "^19.0.0"
+    "vite": "^6.0.0"
   }
 }