FIRST JACK - MOBILE LOAD FIX V4

What this fixes:
- Prevents a blank storefront when the main JavaScript bundle is rejected as an ES module or served with the wrong MIME type.
- Uses a versioned classic deferred bundle: assets/storefront-mobile-v4.js
- Forces fresh HTML/PHP responses via root .htaccess to avoid stale index/asset mismatches on phones.
- Keeps static assets cacheable.
- Replaces direct AbortSignal.timeout usage with AbortController + setTimeout for wider Safari/iOS compatibility.
- Adds a visible refresh fallback instead of leaving customers on a completely blank page if the storefront script fails.

Deployment:
1. Upload/extract ALL files into the same document root where firstjack.shop currently points.
2. Confirm /assets/storefront-mobile-v4.js exists after extraction.
3. Replace index.html and root .htaccess with the included versions.
4. Do not delete the ai/ folder/database configuration.
5. Open https://firstjack.shop/?v=4 once on the phone, then refresh.
