feat(admin): separate platform CRUD from CMS, add entity selector macro

- Move platforms menu from CMS to Platform Admin section with create/edit
- Add platform create page, API endpoint, and service method
- Remove CMS-specific content from platform list and detail pages
- Create shared entity_selector + entity_selected_badge Jinja macros
- Create entity-selector.js generalizing store-selector.js for any entity
- Add Tom Select merchant filter to stores page with localStorage persistence
- Migrate store-products page to use shared macros (remove 53 lines of duped CSS)
- Fix broken icons: puzzle→puzzle-piece, building-storefront→store, language→translate, server→cube

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

app/modules/tenancy/static/admin/js/stores.js

@@ -28,11 +28,16 @@ function adminStores() {
         showDeleteStoreModal: false,
         storeToDelete: null,
 
+        // Merchant filter (Tom Select)
+        selectedMerchant: null,
+        merchantSelectInstance: null,
+
         // Search and filters
         filters: {
             search: '',
             is_active: '',
-            is_verified: ''
+            is_verified: '',
+            merchant_id: ''
         },
 
         // Pagination state (server-side)
@@ -62,9 +67,16 @@ function adminStores() {
                 this.pagination.per_page = await window.PlatformSettings.getRowsPerPage();
             }
 
+            // Initialize merchant selector (Tom Select)
+            this.$nextTick(() => {
+                this.initMerchantSelect();
+            });
+
             storesLog.group('Loading stores data');
-            await this.loadStores();
-            await this.loadStats();
+            await Promise.all([
+                this.loadStores(),
+                this.loadStats(),
+            ]);
             storesLog.groupEnd();
 
             storesLog.info('=== STORES PAGE INITIALIZATION COMPLETE ===');
@@ -163,6 +175,9 @@ function adminStores() {
                 if (this.filters.is_verified !== '') {
                     params.append('is_verified', this.filters.is_verified);
                 }
+                if (this.filters.merchant_id !== '') {
+                    params.append('merchant_id', this.filters.merchant_id);
+                }
 
                 const url = `/admin/stores?${params}`;
                 window.LogConfig.logApiCall('GET', url, null, 'request');
@@ -230,6 +245,64 @@ function adminStores() {
             }
         },
 
+        // Initialize merchant selector (Tom Select autocomplete)
+        initMerchantSelect() {
+            if (!window.initEntitySelector) {
+                storesLog.warn('initEntitySelector not available yet, retrying...');
+                setTimeout(() => this.initMerchantSelect(), 200);
+                return;
+            }
+
+            this.merchantSelectInstance = initEntitySelector(this.$refs.merchantSelect, {
+                apiEndpoint: '/admin/merchants',
+                responseKey: 'merchants',
+                searchFields: ['name'],
+                codeField: null,
+                placeholder: 'Filter by merchant...',
+                noResultsText: 'No merchants found',
+                onSelect: (merchant) => {
+                    storesLog.info('Merchant selected:', merchant);
+                    this.selectedMerchant = merchant;
+                    this.filters.merchant_id = merchant.id;
+                    this.pagination.page = 1;
+                    localStorage.setItem('stores_selected_merchant_id', merchant.id);
+                    localStorage.setItem('stores_selected_merchant_data', JSON.stringify(merchant));
+                    this.loadStores();
+                },
+                onClear: () => {
+                    this.clearMerchantFilter();
+                }
+            });
+
+            // Restore from localStorage
+            const savedMerchantId = localStorage.getItem('stores_selected_merchant_id');
+            if (savedMerchantId) {
+                const savedData = JSON.parse(localStorage.getItem('stores_selected_merchant_data') || 'null');
+                if (savedData) {
+                    this.selectedMerchant = savedData;
+                    this.filters.merchant_id = parseInt(savedMerchantId);
+                    // Wait for Tom Select to init, then set value
+                    setTimeout(() => {
+                        this.merchantSelectInstance?.setValue(parseInt(savedMerchantId), savedData);
+                    }, 500);
+                }
+            }
+        },
+
+        // Clear merchant filter
+        clearMerchantFilter() {
+            storesLog.info('Clearing merchant filter');
+            this.selectedMerchant = null;
+            this.filters.merchant_id = '';
+            this.pagination.page = 1;
+            localStorage.removeItem('stores_selected_merchant_id');
+            localStorage.removeItem('stores_selected_merchant_data');
+            if (this.merchantSelectInstance) {
+                this.merchantSelectInstance.clear();
+            }
+            this.loadStores();
+        },
+
         // Pagination: Go to specific page
         goToPage(pageNum) {
             if (pageNum === '...' || pageNum < 1 || pageNum > this.totalPages) {