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/frontend/cdn-fallback-strategy.md

@@ -189,7 +189,7 @@ app/templates/shared/
 
 ### Shop Frontend
 
-**Template:** `app/templates/shop/base.html`
+**Template:** `app/templates/storefront/base.html`
 
 ```html
 {# Lines 41-42: Tailwind CSS fallback #}