Fix import error: move AuthResult and User imports to module level

- Move AuthResult, User imports from method level to module level
- Fixes NameError: name 'AuthResult' is not defined at import time
- Remove redundant imports inside _create_oauth_user method
- Ensures all type hints are properly resolved during module loading

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

digipal/ui/gradio_interface.py

@@ -16,7 +16,7 @@ import io
 from ..core.digipal_core import DigiPalCore, PetState
 from ..core.enums import EggType, LifeStage
 from ..auth.auth_manager import AuthManager
-from ..auth.models import AuthStatus
+from ..auth.models import AuthStatus, AuthResult, User
 from ..storage.database import DatabaseConnection
 
 logger = logging.getLogger(__name__)
@@ -641,7 +641,6 @@ class GradioInterface:
     def _create_oauth_user(self, user_id: str, username: str, oauth_info: Dict) -> Optional[AuthResult]:
         """Create or update user from OAuth information."""
         try:
-            from ..auth.models import User, AuthResult, AuthStatus
             from datetime import datetime
             
             # Extract user data from OAuth info