Add authentication system and admin panel

- Implement JWT-based authentication with login/logout
- Add user management routes and middleware
- Create admin panel for managing words and categories
- Add authentication store and API client
- Update database schema with User model
- Configure CORS and authentication middleware
- Add login page and protected routes

packages/backend/package.json

@@ -14,6 +14,9 @@
     "prisma:studio": "prisma studio",
     "prisma:seed": "tsx prisma/seed.ts"
   },
+  "prisma": {
+    "seed": "tsx prisma/seed.ts"
+  },
   "dependencies": {
     "express": "^4.18.2",
     "cors": "^2.8.5",