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/shop/content_pages.py

@@ -8,6 +8,7 @@ No authentication required.
 
 import logging
 from typing import List
+
 from fastapi import APIRouter, Depends, HTTPException, Request
 from pydantic import BaseModel
 from sqlalchemy.orm import Session
@@ -23,8 +24,10 @@ logger = logging.getLogger(__name__)
 # RESPONSE SCHEMAS
 # ============================================================================
 
+
 class PublicContentPageResponse(BaseModel):
     """Public content page response (no internal IDs)."""
+
     slug: str
     title: str
     content: str
@@ -36,6 +39,7 @@ class PublicContentPageResponse(BaseModel):
 
 class ContentPageListItem(BaseModel):
     """Content page list item for navigation."""
+
     slug: str
     title: str
     show_in_footer: bool
@@ -47,25 +51,21 @@ class ContentPageListItem(BaseModel):
 # PUBLIC ENDPOINTS
 # ============================================================================
 
+
 @router.get("/navigation", response_model=List[ContentPageListItem])
-def get_navigation_pages(
-    request: Request,
-    db: Session = Depends(get_db)
-):
+def get_navigation_pages(request: Request, db: Session = Depends(get_db)):
     """
     Get list of content pages for navigation (footer/header).
 
     Uses vendor from request.state (set by middleware).
     Returns vendor overrides + platform defaults.
     """
-    vendor = getattr(request.state, 'vendor', None)
+    vendor = getattr(request.state, "vendor", None)
     vendor_id = vendor.id if vendor else None
 
     # Get all published pages for this vendor
     pages = content_page_service.list_pages_for_vendor(
-        db,
-        vendor_id=vendor_id,
-        include_unpublished=False
+        db, vendor_id=vendor_id, include_unpublished=False
     )
 
     return [
@@ -81,25 +81,21 @@ def get_navigation_pages(
 
 
 @router.get("/{slug}", response_model=PublicContentPageResponse)
-def get_content_page(
-    slug: str,
-    request: Request,
-    db: Session = Depends(get_db)
-):
+def get_content_page(slug: str, request: Request, db: Session = Depends(get_db)):
     """
     Get a specific content page by slug.
 
     Uses vendor from request.state (set by middleware).
     Returns vendor override if exists, otherwise platform default.
     """
-    vendor = getattr(request.state, 'vendor', None)
+    vendor = getattr(request.state, "vendor", None)
     vendor_id = vendor.id if vendor else None
 
     page = content_page_service.get_page_for_vendor(
         db,
         slug=slug,
         vendor_id=vendor_id,
-        include_unpublished=False  # Only show published pages
+        include_unpublished=False,  # Only show published pages
     )
 
     if not page: