chore: migrate to @vigdorov/* shared configs (eslint, prettier, typescript, vite)

Replace project-local ESLint, Prettier, TypeScript, and Vite configs
with shared packages from dev-configs monorepo.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/package.json

@@ -30,18 +30,14 @@
     "zustand": "^5.0.9"
   },
   "devDependencies": {
-    "@eslint/js": "^9.39.1",
     "@types/node": "^24.10.1",
     "@types/react": "^19.2.5",
     "@types/react-dom": "^19.2.3",
-    "@vitejs/plugin-react": "^5.1.1",
+    "@vigdorov/eslint-config": "^1.0.1",
+    "@vigdorov/typescript-config": "^1.1.0",
+    "@vigdorov/vite-config": "^1.0.0",
     "eslint": "^9.39.1",
-    "eslint-plugin-react-hooks": "^7.0.1",
-    "eslint-plugin-react-refresh": "^0.4.24",
-    "globals": "^16.5.0",
-    "prettier": "^3.4.2",
     "typescript": "~5.9.3",
-    "typescript-eslint": "^8.46.4",
     "vite": "^7.2.4"
   }
 }