docs: update testing guide and sidebar documentation

- Add Testing Hub (Admin Dashboard) section to testing guide
  - Document features: collection, running tests, statistics
  - Document API endpoints and background execution
- Update sidebar documentation for new structure:
  - Add Product Catalog section
  - Add Platform Health section (Testing Hub, Code Quality, Background Tasks)
  - Update Settings to collapsible section
  - Update page-to-section mappings

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

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

docs/frontend/shared/sidebar.md

@@ -15,11 +15,13 @@ The sidebar is organized into the following sections:
 | Section | Collapsible | Pages |
 |---------|-------------|-------|
 | Dashboard | No | Dashboard |
-| Platform Administration | Yes | Companies, Vendors, Users, Customers, Marketplace |
+| Platform Administration | Yes | Companies, Vendors, Users, Customers |
+| Product Catalog | Yes | Marketplace Products, Vendor Products, Import |
 | Content Management | Yes | Platform Homepage, Content Pages, Vendor Themes |
-| Developer Tools | Yes | Components, Icons, Testing Hub, Code Quality |
+| Developer Tools | Yes | Components, Icons |
+| Platform Health | Yes | Testing Hub, Code Quality, Background Tasks |
 | Platform Monitoring | Yes | Import Jobs, Application Logs |
-| Settings | No | Settings |
+| Settings | Yes | General, Profile, API Keys, Notifications |
 
 ---
 
@@ -37,9 +39,12 @@ Sections can be expanded/collapsed by clicking the section header. The state is
 // Default state: Platform Administration open, others closed
 const defaultSections = {
     platformAdmin: true,
+    productCatalog: false,
     contentMgmt: false,
     devTools: false,
-    monitoring: false
+    platformHealth: false,
+    monitoring: false,
+    settingsSection: false
 };
 
 // State stored in localStorage under this key
@@ -53,9 +58,12 @@ const SIDEBAR_STORAGE_KEY = 'admin_sidebar_sections';
 | `toggleSection(section)` | Toggle a section open/closed |
 | `expandSectionForCurrentPage()` | Auto-expand section containing current page |
 | `openSections.platformAdmin` | Check if Platform Administration is open |
+| `openSections.productCatalog` | Check if Product Catalog is open |
 | `openSections.contentMgmt` | Check if Content Management is open |
 | `openSections.devTools` | Check if Developer Tools is open |
+| `openSections.platformHealth` | Check if Platform Health is open |
 | `openSections.monitoring` | Check if Platform Monitoring is open |
+| `openSections.settingsSection` | Check if Settings is open |
 
 ### CSS Transitions
 
@@ -98,7 +106,10 @@ const pageSectionMap = {
     vendors: 'platformAdmin',
     users: 'platformAdmin',
     customers: 'platformAdmin',
-    marketplace: 'platformAdmin',
+    // Product Catalog
+    'marketplace-products': 'productCatalog',
+    'vendor-products': 'productCatalog',
+    marketplace: 'productCatalog',
     // Content Management
     'platform-homepage': 'contentMgmt',
     'content-pages': 'contentMgmt',
@@ -106,11 +117,18 @@ const pageSectionMap = {
     // Developer Tools
     components: 'devTools',
     icons: 'devTools',
-    testing: 'devTools',
-    'code-quality': 'devTools',
+    // Platform Health
+    testing: 'platformHealth',
+    'code-quality': 'platformHealth',
+    'background-tasks': 'platformHealth',
     // Platform Monitoring
     imports: 'monitoring',
-    logs: 'monitoring'
+    logs: 'monitoring',
+    // Settings
+    settings: 'settingsSection',
+    profile: 'settingsSection',
+    'api-keys': 'settingsSection',
+    'notifications-settings': 'settingsSection'
 };
 ```
 
@@ -125,17 +143,23 @@ const pageSectionMap = {
 | Vendors | `'vendors'` | Platform Administration | `/admin/vendors` |
 | Users | `'users'` | Platform Administration | `/admin/users` |
 | Customers | `'customers'` | Platform Administration | `/admin/customers` |
-| Marketplace | `'marketplace'` | Platform Administration | `/admin/marketplace` |
+| Marketplace Products | `'marketplace-products'` | Product Catalog | `/admin/marketplace-products` |
+| Vendor Products | `'vendor-products'` | Product Catalog | `/admin/vendor-products` |
+| Import | `'marketplace'` | Product Catalog | `/admin/marketplace` |
 | Platform Homepage | `'platform-homepage'` | Content Management | `/admin/platform-homepage` |
 | Content Pages | `'content-pages'` | Content Management | `/admin/content-pages` |
 | Vendor Themes | `'vendor-theme'` | Content Management | `/admin/vendor-themes` |
 | Components | `'components'` | Developer Tools | `/admin/components` |
 | Icons | `'icons'` | Developer Tools | `/admin/icons` |
-| Testing Hub | `'testing'` | Developer Tools | `/admin/testing` |
-| Code Quality | `'code-quality'` | Developer Tools | `/admin/code-quality` |
+| Testing Hub | `'testing'` | Platform Health | `/admin/testing` |
+| Code Quality | `'code-quality'` | Platform Health | `/admin/code-quality` |
+| Background Tasks | `'background-tasks'` | Platform Health | `/admin/background-tasks` |
 | Import Jobs | `'imports'` | Platform Monitoring | `/admin/imports` |
 | Application Logs | `'logs'` | Platform Monitoring | `/admin/logs` |
-| Settings | `'settings'` | (always visible) | `/admin/settings` |
+| General Settings | `'settings'` | Settings | `/admin/settings` |
+| Profile | `'profile'` | Settings | `/admin/profile` |
+| API Keys | `'api-keys'` | Settings | `/admin/api-keys` |
+| Notifications | `'notifications-settings'` | Settings | `/admin/notifications-settings` |
 
 ---