Major fixes:
- Fix JSON body parsing in load_products_ajax with type='http' route
* Parse JSON from request.httprequest.get_data() instead of post params
* Correctly read page, search, category from JSON request body
- Fix search and category filter combination
* Use intersection (&) instead of replacement to preserve both filters
* Now respects search AND category simultaneously
- Integrate realtime_search.js with infinite_scroll.js
* Add resetWithFilters() method to reset scroll to page 1 with new filters
* When search/category changes, reload products from server
* Clear grid and load fresh results
- Fix pagination reset logic
* Set currentPage = 0 in resetWithFilters() so loadNextPage() increments to 1
* Prevents loading empty page 2 when resetting filters
Results:
✅ Infinite scroll loads all pages correctly (1, 2, 3...)
✅ Search filters work across all products (not just loaded)
✅ Category filters work correctly
✅ Search AND category filters work together
✅ Page resets to 1 when filters change
