refactor: rename shop to storefront throughout codebase

Rename "shop" to "storefront" as not all platforms sell items -
storefront is a more accurate term for the customer-facing interface.

Changes:
- Rename app/api/v1/shop/ → app/api/v1/storefront/
- Rename app/routes/shop_pages.py → app/routes/storefront_pages.py
- Rename app/modules/cms/routes/api/shop.py → storefront.py
- Rename tests/integration/api/v1/shop/ → storefront/
- Update API prefix from /api/v1/shop to /api/v1/storefront
- Update route tags from shop-* to storefront-*
- Rename get_shop_context() → get_storefront_context()
- Update architecture rules to reference storefront paths
- Update all test API endpoint paths

This is Phase 2 of the storefront module restructure plan.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/cms/routes/api/storefront.py

@@ -0,0 +1,84 @@
+# app/modules/cms/routes/api/storefront.py
+"""
+Storefront Content Pages API (Public)
+
+Public endpoints for retrieving content pages in storefront.
+No authentication required.
+"""
+
+import logging
+
+from fastapi import APIRouter, Depends, Request
+from sqlalchemy.orm import Session
+
+from app.core.database import get_db
+from app.modules.cms.schemas import (
+    PublicContentPageResponse,
+    ContentPageListItem,
+)
+from app.modules.cms.services import content_page_service
+
+router = APIRouter()
+logger = logging.getLogger(__name__)
+
+
+# ============================================================================
+# PUBLIC ENDPOINTS
+# ============================================================================
+
+
+@router.get("/navigation", response_model=list[ContentPageListItem])
+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_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
+    )
+
+    return [
+        {
+            "slug": page.slug,
+            "title": page.title,
+            "show_in_footer": page.show_in_footer,
+            "show_in_header": page.show_in_header,
+            "display_order": page.display_order,
+        }
+        for page in pages
+    ]
+
+
+@router.get("/{slug}", response_model=PublicContentPageResponse)
+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_id = vendor.id if vendor else None
+
+    page = content_page_service.get_page_for_vendor_or_raise(
+        db,
+        slug=slug,
+        vendor_id=vendor_id,
+        include_unpublished=False,  # Only show published pages
+    )
+
+    return {
+        "slug": page.slug,
+        "title": page.title,
+        "content": page.content,
+        "content_format": page.content_format,
+        "meta_description": page.meta_description,
+        "meta_keywords": page.meta_keywords,
+        "published_at": page.published_at.isoformat() if page.published_at else None,
+    }