Replace midpoint split with MFA-based splitting for combined/fused segments

Fix var shadowing that broke Animate All button and accordion

Persist accordion open/closed state separately for main view and Animate All

Open Animation Settings accordion by default and persist state in localStorage

Fix special segments (Basmala/Isti'adha) not sent to MFA or animated in mega card

Always show mega styling sliders (text size, word/line spacing)

Optimize applyWindowOpacity with delta updates for large recordings

5B: Extract JS into static files + js_config.py bridge