docs: add consolidated dev URL reference and migrate /shop to /storefront

- Add Development URL Quick Reference section to url-routing overview
  with all login URLs, entry points, and full examples
- Replace /shop/ path segments with /storefront/ across 50 docs files
- Update file references: shop_pages.py → storefront_pages.py,
  templates/shop/ → templates/storefront/, api/v1/shop/ → api/v1/storefront/
- Preserve domain references (orion.shop) and /store/ staff dashboard paths
- Archive docs left unchanged (historical)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/backend/overview.md

@@ -14,13 +14,13 @@ app/
 │   ├── v1/                # Version 1 API
 │   │   ├── admin/        # Admin API endpoints
 │   │   ├── store/       # Store API endpoints
-│   │   └── shop/         # Shop API endpoints
+│   │   └── storefront/   # Storefront API endpoints
 │   └── main.py           # API router configuration
 │
 ├── routes/               # Page routes (HTML)
 │   ├── admin_pages.py   # Admin page routes
 │   ├── store_pages.py  # Store page routes
-│   └── shop_pages.py    # Shop page routes
+│   └── storefront_pages.py    # Storefront page routes
 │
 ├── services/            # Business logic layer
 │   ├── admin_service.py
@@ -84,7 +84,7 @@ class ProductService:
 
 product_service = ProductService()
 
-# Step 3: API Route (app/api/v1/shop/products.py)
+# Step 3: API Route (app/api/v1/storefront/products.py)
 from fastapi import APIRouter, Depends
 from sqlalchemy.orm import Session
 from app.core.database import get_db