Add babel-plugin-module-resolver (required for release JS bundling)

The '@/' import alias needs this plugin; debug builds hid the gap because
they bundle lazily via Metro. Release (standalone) bundling now succeeds.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/package.json

@@ -34,6 +34,7 @@
   },
   "devDependencies": {
     "@types/react": "~19.0.0",
+    "babel-plugin-module-resolver": "^5.0.2",
     "typescript": "~5.4.0"
   }
 }