refactor(api): introduce UserContext schema for API dependency injection

Replace direct User database model imports in API endpoints with UserContext
schema, following the architecture principle that API routes should not import
database models directly.

Changes:
- Create UserContext schema in models/schema/auth.py with from_user() factory
- Update app/api/deps.py to return UserContext from all auth dependencies
- Add _get_user_model() helper for functions needing User model access
- Update 58 API endpoint files to use UserContext instead of User
- Add noqa comments for 4 legitimate edge cases (enums, internal helpers)

Architecture validation: 0 errors (down from 61), 11 warnings remain

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/api/v1/admin/module_config.py

@@ -22,7 +22,7 @@ from app.exceptions import ValidationException
 from app.modules.registry import MODULES
 from app.modules.service import module_service
 from app.services.platform_service import platform_service
-from models.database.user import User
+from models.schema.auth import UserContext
 
 logger = logging.getLogger(__name__)
 router = APIRouter(prefix="/module-config")
@@ -267,7 +267,7 @@ async def get_module_config(
     platform_id: int = Path(..., description="Platform ID"),
     module_code: str = Path(..., description="Module code"),
     db: Session = Depends(get_db),
-    current_user: User = Depends(get_current_super_admin),
+    current_user: UserContext = Depends(get_current_super_admin),
 ):
     """
     Get configuration for a specific module on a platform.
@@ -311,7 +311,7 @@ async def update_module_config(
     platform_id: int = Path(..., description="Platform ID"),
     module_code: str = Path(..., description="Module code"),
     db: Session = Depends(get_db),
-    current_user: User = Depends(get_current_super_admin),
+    current_user: UserContext = Depends(get_current_super_admin),
 ):
     """
     Update configuration for a specific module on a platform.
@@ -354,7 +354,7 @@ async def update_module_config(
 @router.get("/defaults/{module_code}", response_model=ConfigDefaultsResponse)
 async def get_config_defaults(
     module_code: str = Path(..., description="Module code"),
-    current_user: User = Depends(get_current_super_admin),
+    current_user: UserContext = Depends(get_current_super_admin),
 ):
     """
     Get default configuration for a module.
@@ -386,7 +386,7 @@ async def reset_module_config(
     platform_id: int = Path(..., description="Platform ID"),
     module_code: str = Path(..., description="Module code"),
     db: Session = Depends(get_db),
-    current_user: User = Depends(get_current_super_admin),
+    current_user: UserContext = Depends(get_current_super_admin),
 ):
     """
     Reset module configuration to defaults.