- Add expand button with Maximize2/Minimize2 icons
- Implement 3-state height management (normal/50%/80%)
- Smart double-click detection with 300ms delay
- Height calculation based on session-view - 200px message space
- Custom CSS tooltip with dark gradient background and backdrop blur
- Send button anchored at bottom via margin-top: auto
- Smooth CSS transitions throughout
- Double-click at 80% now reduces to 50% (not normal)
- Removed all debug console.log statements