Add store items pagination and fix modal backdrop blur across dashboards.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/business/src/services/storeItemService.ts

@@ -1,6 +1,9 @@
 import { apiRequest } from '../lib/api'
 import { getActiveBusinessId } from '../lib/businessContext'
 
+/** Product cards per page on My Store Items (grid). */
+export const STORE_ITEMS_PER_PAGE = 24
+
 export interface StoreItemSelection {
   variationId: string
   variationName: string