refactor: rename Product Catalog to Vendor Operations

- Rename sidebar section from "Product Catalog" to "Vendor Operations"
- Change section key from 'productCatalog' to 'vendorOps'
- Add placeholder comments for future items (Inventory, Orders, Shipping)
- Update pageSectionMap in init-alpine.js

This prepares the sidebar for expanded vendor management capabilities
including inventory, orders, and shipping management.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/templates/admin/partials/sidebar.html

@@ -75,11 +75,16 @@
         {{ menu_item('customers', '/admin/customers', 'user-group', 'Customers') }}
     {% endcall %}
 
-    <!-- Product Catalog Section -->
-    {{ section_header('Product Catalog', 'productCatalog') }}
-    {% call section_content('productCatalog') %}
+    <!-- Vendor Operations Section -->
+    {{ section_header('Vendor Operations', 'vendorOps') }}
+    {% call section_content('vendorOps') %}
         {{ menu_item('marketplace-products', '/admin/marketplace-products', 'database', 'Marketplace Products') }}
         {{ menu_item('vendor-products', '/admin/vendor-products', 'cube', 'Vendor Products') }}
+        {# Future items - uncomment when implemented:
+        {{ menu_item('inventory', '/admin/inventory', 'archive', 'Inventory') }}
+        {{ menu_item('orders', '/admin/orders', 'clipboard-list', 'Orders') }}
+        {{ menu_item('shipping', '/admin/shipping', 'truck', 'Shipping') }}
+        #}
     {% endcall %}
 
     <!-- Marketplace Section -->

static/admin/js/init-alpine.js

@@ -28,7 +28,7 @@ function data() {
   // Default state: Platform Administration open, others closed
   const defaultSections = {
     platformAdmin: true,
-    productCatalog: false,
+    vendorOps: false,
     marketplace: false,
     contentMgmt: false,
     devTools: false,
@@ -64,9 +64,10 @@ function data() {
     vendors: 'platformAdmin',
     users: 'platformAdmin',
     customers: 'platformAdmin',
-    // Product Catalog
-    'marketplace-products': 'productCatalog',
-    'vendor-products': 'productCatalog',
+    // Vendor Operations (Products, Inventory, Orders, Shipping)
+    'marketplace-products': 'vendorOps',
+    'vendor-products': 'vendorOps',
+    // Future: inventory, orders, shipping will map to 'vendorOps'
     // Marketplace
     'marketplace-letzshop': 'marketplace',
     // Content Management