fix: resolve Docker build issues

- Update .gitignore to allow moveIndex.json (needed at build time)
- Exclude only eco*.json files (too large for git)
- Add uuid package dependency for sessionManager

Fixes:
- Next.js build error: Module not found moveIndex.json
- Build error: Module not found uuid

package.json

@@ -39,7 +39,8 @@
     "react-dom": "19.2.0",
     "react-markdown": "^10.1.0",
     "stockfish.js": "^10.0.2",
-    "tailwind-merge": "^3.4.0"
+    "tailwind-merge": "^3.4.0",
+    "uuid": "^13.0.0"
   },
   "devDependencies": {
     "@playwright/test": "^1.57.0",