style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

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

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

app/api/v1/admin/auth.py

@@ -10,16 +10,17 @@ This prevents admin cookies from being sent to vendor routes.
 """
 
 import logging
+
 from fastapi import APIRouter, Depends, Response
 from sqlalchemy.orm import Session
 
+from app.api.deps import get_current_admin_api
 from app.core.database import get_db
 from app.core.environment import should_use_secure_cookies
-from app.services.auth_service import auth_service
 from app.exceptions import InvalidCredentialsException
-from models.schema.auth import LoginResponse, UserLogin, UserResponse
+from app.services.auth_service import auth_service
 from models.database.user import User
-from app.api.deps import get_current_admin_api
+from models.schema.auth import LoginResponse, UserLogin, UserResponse
 
 router = APIRouter(prefix="/auth")
 logger = logging.getLogger(__name__)
@@ -27,9 +28,7 @@ logger = logging.getLogger(__name__)
 
 @router.post("/login", response_model=LoginResponse)
 def admin_login(
-        user_credentials: UserLogin,
-        response: Response,
-        db: Session = Depends(get_db)
+    user_credentials: UserLogin, response: Response, db: Session = Depends(get_db)
 ):
     """
     Admin login endpoint.
@@ -49,7 +48,9 @@ def admin_login(
 
     # Verify user is admin
     if login_result["user"].role != "admin":
-        logger.warning(f"Non-admin user attempted admin login: {user_credentials.email_or_username}")
+        logger.warning(
+            f"Non-admin user attempted admin login: {user_credentials.email_or_username}"
+        )
         raise InvalidCredentialsException("Admin access required")
 
     logger.info(f"Admin login successful: {login_result['user'].username}")