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>

tests/integration/middleware/conftest.py

@@ -3,6 +3,7 @@
 Fixtures specific to middleware integration tests.
 """
 import pytest
+
 from models.database.vendor import Vendor
 from models.database.vendor_domain import VendorDomain
 from models.database.vendor_theme import VendorTheme
@@ -12,10 +13,7 @@ from models.database.vendor_theme import VendorTheme
 def vendor_with_subdomain(db):
     """Create a vendor with subdomain for testing."""
     vendor = Vendor(
-        name="Test Vendor",
-        code="testvendor",
-        subdomain="testvendor",
-        is_active=True
+        name="Test Vendor", code="testvendor", subdomain="testvendor", is_active=True
     )
     db.add(vendor)
     db.commit()
@@ -30,7 +28,7 @@ def vendor_with_custom_domain(db):
         name="Custom Domain Vendor",
         code="customvendor",
         subdomain="customvendor",
-        is_active=True
+        is_active=True,
     )
     db.add(vendor)
     db.commit()
@@ -38,10 +36,7 @@ def vendor_with_custom_domain(db):
 
     # Add custom domain
     domain = VendorDomain(
-        vendor_id=vendor.id,
-        domain="customdomain.com",
-        is_active=True,
-        is_primary=True
+        vendor_id=vendor.id, domain="customdomain.com", is_active=True, is_primary=True
     )
     db.add(domain)
     db.commit()
@@ -56,7 +51,7 @@ def vendor_with_theme(db):
         name="Themed Vendor",
         code="themedvendor",
         subdomain="themedvendor",
-        is_active=True
+        is_active=True,
     )
     db.add(vendor)
     db.commit()
@@ -69,7 +64,7 @@ def vendor_with_theme(db):
         secondary_color="#33FF57",
         logo_url="/static/vendors/themedvendor/logo.png",
         favicon_url="/static/vendors/themedvendor/favicon.ico",
-        custom_css="body { background: #FF5733; }"
+        custom_css="body { background: #FF5733; }",
     )
     db.add(theme)
     db.commit()
@@ -81,10 +76,7 @@ def vendor_with_theme(db):
 def inactive_vendor(db):
     """Create an inactive vendor for testing."""
     vendor = Vendor(
-        name="Inactive Vendor",
-        code="inactive",
-        subdomain="inactive",
-        is_active=False
+        name="Inactive Vendor", code="inactive", subdomain="inactive", is_active=False
     )
     db.add(vendor)
     db.commit()