feat: add Playwright configuration and initial e2e test for authentication

- Created Playwright configuration file to set up testing environment.
- Added a new e2e test for user authentication in login.spec.ts.
- Updated tsconfig.node.json to include playwright.config.ts.
- Enhanced vite.config.ts to include API proxying for backend integration.
- Added a placeholder for last run test results in .last-run.json.

backend/app/repositories/__init__.py

@@ -1,11 +1,15 @@
 """Repository abstractions for database access."""
 
 from backend.app.repositories.stations import StationRepository
+from backend.app.repositories.train_schedules import TrainScheduleRepository
 from backend.app.repositories.tracks import TrackRepository
 from backend.app.repositories.trains import TrainRepository
+from backend.app.repositories.users import UserRepository
 
 __all__ = [
     "StationRepository",
+    "TrainScheduleRepository",
     "TrackRepository",
     "TrainRepository",
+    "UserRepository",
 ]