Phase 1 - UI Theme Consistency:
- Chat messages now use consistent dark theme (removed jarring white bg)
- Plan cards restyled with rounded borders, fills, colored status badges
- Timeline entries use humanist sans-serif instead of monospace
- Error messages now structured (icon + title + detail + action link)
- Input area unified with dark theme cohesion
Phase 2 - UX Flow:
- Added contextual placeholder text per agent mode in textarea
- Added visual mode indicator badge (Chat/Planning/Writing)
- Simplified welcome screen (single 'Continue' + collapsible history)
- Added slash command/mention discovery hint in empty input
- Added write confirmation when editor has existing content
- Added 30s streaming heartbeat (reassurance when model is slow)
Phase 3 - Error Handling:
- Added DB table health check on sidebar init
- Improved 'no API key' error with settings link
- Shows in-chat warning when provider fallback triggers
- Auto-fallback to registry fallback model on unavailability
- isLoading always resets via try/finally pattern
f7bf1f5153