tiviLux V15 — Web + Mobile Operating Overhaul

Preserved:
- Opening playlist update screen
- Provider/profile/account flow
- Live TV + unified guide
- Sports Zone
- Movies, Series, Favorites, Search
- Fullscreen/PiP/remote controls
- Existing server/database structure

Major improvements:
- Progressive TV-guide loading instead of building every channel row at once
- Lazy EPG loading with mobile-aware request concurrency
- Infinite/progressive movie and series browsing (no heavy page rebuilds)
- New responsive layout and larger/tighter mobile touch controls
- Reduced mobile rendering work and improved large-library scrolling
- Adaptive HLS buffer sizing for phones/lower-memory devices
- Stronger HLS retry tuning and faster recovery behavior
- Sports source selector for All Sports / NFL / MLB / PPV
- NFL, MLB and PPV source modes restrict scanning to matching Live TV categories
- Improved startup/update screen mobile layout
- New service-worker cache namespace so V15 assets replace V14.2 cleanly