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-lock.json

@@ -23,7 +23,8 @@
         "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",
@@ -13353,6 +13354,19 @@
       "integrity": "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==",
       "license": "MIT"
     },
+    "node_modules/uuid": {
+      "version": "13.0.0",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-13.0.0.tgz",
+      "integrity": "sha512-XQegIaBTVUjSHliKqcnFqYypAd4S+WCYt5NIeRs6w/UAry7z8Y9j5ZwRRL4kzq9U3sD6v+85er9FvkEaBpji2w==",
+      "funding": [
+        "https://github.com/sponsors/broofa",
+        "https://github.com/sponsors/ctavan"
+      ],
+      "license": "MIT",
+      "bin": {
+        "uuid": "dist-node/bin/uuid"
+      }
+    },
     "node_modules/v8-compile-cache-lib": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/v8-compile-cache-lib/-/v8-compile-cache-lib-3.0.1.tgz",