Add True Shot Ammo (Shopify JSON), Palmetto State Armory (Magento HTML),
Bulk Ammo (Magento HTML), and Natchez Shooters Supply (GraphQL API).
Extends scraper infrastructure with HttpClient.post_json/3 and an
optional fetch/2 callback on the Scraper behaviour for scrapers that
need custom HTTP flows (e.g. GraphQL POST requests).
- Add subsonic boolean field to products with composite filter indexes
- Add TextDetector utility for detecting subsonic/casing from product titles
- Wire TextDetector into SgAmmo (casing + subsonic) and LuckyGunner (subsonic + fallback casing)
- Extend latest_prices_for_caliber with casing, grain_weight, and subsonic filter options
- Add distinct_grain_weights_for_caliber and distinct_casings_for_caliber queries
- Add filter UI with toggleable casing, grain weight, and subsonic buttons
- Add grain weight column and subsonic badge to product table
- Refresh filter options on PubSub price updates for real-time UI
- Implement Target Sports USA scraper with 18 caliber mappings
- Display all prices in dollar format ($0.38 instead of 38¢)