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/vendor/__init__.py

@@ -13,25 +13,9 @@ IMPORTANT:
 from fastapi import APIRouter
 
 # Import all sub-routers (JSON API only)
-from . import (
-    info,
-    auth,
-    dashboard,
-    profile,
-    settings,
-    products,
-    orders,
-    customers,
-    team,
-    inventory,
-    marketplace,
-    payments,
-    media,
-    notifications,
-    analytics,
-    content_pages,
-)
-
+from . import (analytics, auth, content_pages, customers, dashboard, info,
+               inventory, marketplace, media, notifications, orders, payments,
+               products, profile, settings, team)
 
 # Create vendor router
 router = APIRouter()
@@ -68,7 +52,11 @@ router.include_router(notifications.router, tags=["vendor-notifications"])
 router.include_router(analytics.router, tags=["vendor-analytics"])
 
 # Content pages management
-router.include_router(content_pages.router, prefix="/{vendor_code}/content-pages", tags=["vendor-content-pages"])
+router.include_router(
+    content_pages.router,
+    prefix="/{vendor_code}/content-pages",
+    tags=["vendor-content-pages"],
+)
 
 # Vendor info endpoint - MUST BE LAST! Has catch-all GET /{vendor_code}
 router.include_router(info.router, tags=["vendor-info"])