V39 RECOVERY BUILD

Restored the original working application boot chain from V34:
- Original .htaccess DirectoryIndex and SPA fallback
- Original index.php bootstrap flow
- Original index.html main bundle reference
- Original service worker
- Removed V36 renamed main bundle

The remaining V37 backend fixes are retained. This build specifically removes the API-popup/boot-chain changes that caused the updated packages to fail on shared hosting.
