Removed the restriction that required Evil Mode to be active before
enabling Bipolar Mode. Users can now toggle Bipolar Mode at any time.
Changes:
- Bipolar Mode toggle button now always visible in web UI
- Removed auto-disable of Bipolar Mode when Evil Mode is turned off
- Updated CSS to work in both normal and evil mode states
- Simplified updateBipolarToggleVisibility() to always show button
This allows for more flexible usage where users can have Regular Miku
and Evil Miku argue without needing Evil Mode to be the active persona.