fix(deps): Downgrade eslint-plugin-vue to v9 for ESLint 8 compatibility

eslint-plugin-vue v10 only supports flat config (ESLint 9+),
causing lint-staged to fail on commit with "Unexpected top-level property default".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: leomp12

packages/eslint/package.json

@@ -29,8 +29,8 @@
     "eslint-plugin-astro": "^1.5.0",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-tailwindcss": "3.18.2",
-    "eslint-plugin-vue": "^10.7.0",
+    "eslint-plugin-vue": "^9.32.0",
     "tailwindcss": "^3.4.19",
-    "vue-eslint-parser": "^10.2.0"
+    "vue-eslint-parser": "^9.4.3"
   }
 }