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/analytics.py

@@ -4,13 +4,14 @@ Vendor analytics and reporting endpoints.
 """
 
 import logging
+
 from fastapi import APIRouter, Depends, Query
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_vendor_api
 from app.core.database import get_db
-from middleware.vendor_context import require_vendor_context
 from app.services.stats_service import stats_service
+from middleware.vendor_context import require_vendor_context
 from models.database.user import User
 from models.database.vendor import Vendor
 
@@ -20,10 +21,10 @@ logger = logging.getLogger(__name__)
 
 @router.get("")
 def get_vendor_analytics(
-        period: str = Query("30d", description="Time period: 7d, 30d, 90d, 1y"),
-        vendor: Vendor = Depends(require_vendor_context()),
-        current_user: User = Depends(get_current_vendor_api),
-        db: Session = Depends(get_db),
+    period: str = Query("30d", description="Time period: 7d, 30d, 90d, 1y"),
+    vendor: Vendor = Depends(require_vendor_context()),
+    current_user: User = Depends(get_current_vendor_api),
+    db: Session = Depends(get_db),
 ):
     """Get vendor analytics data for specified time period."""
     return stats_service.get_vendor_analytics(db, vendor.id, period)