Avatars:
- Add avatar_path column to USERS table (migration 006)
- Upload API endpoint /api/asteroid/user/avatar/upload
- Profile page shows avatar with hover-to-change overlay
- Default SVG avatar for users without uploaded image
- Avatars stored in static/avatars/ directory
Fixes:
- 401 errors now return proper JSON instead of 500
- SQL escaping for history recording (single quotes)
- Added debug logging for history/record API
- Avatar container has background color for visibility
For production: run migrations/006-user-avatars.sql