Single separated circle in tab bar (like Photos search icon):
- Home/Fitness: shows + icon, taps opens food assistant
- Reader idle: shows play icon, taps starts auto-scroll
- Reader playing: shows pause icon, taps stops auto-scroll
Icon updates dynamically via computed actionIcon property.
handleActionTap() routes the tap based on selectedTab.
After action, selectedTab returns to the previous tab (doesn't
stay on the invisible "action" tab).
Speed controls still appear as glass capsule overlay when playing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
e2fc87b6aa