fix(admin): make catalog CRUD management visible

- Add management toolbar on /catalog with links to /locations and /categories
- Expand catalog tree by default (all levels visible, no collapsed accordion)
- Add Back to Catalog link on /locations and /categories pages
- Edit/toggle/delete buttons for locations/categories/subcategories now immediately accessible

src/admin/views/locations.ejs

@@ -1,3 +1,4 @@
+<a href="/catalog" class="btn btn-sm btn-outline-secondary mb-2">« Back to Catalog</a>
 <div class="panel panel-icon mb-3">
     <div class="panel-hdr">
         <h2 class="d-flex align-items-center gap-2">