Fix model naming conventions: remove user- prefix from rotation/autoselect model IDs, fetch live provider models

- Add user_id parameter to ContextManager
- Check database for user-specific prompts before filesystem
- Pass user_id from RequestHandler to ContextManager
- Update autoselect prompt loading to respect user-specific prompts
- All authenticated requests get user-specific prompts when available
- Global tokens skip database lookup entirely

- Make user_rotations.html and user_autoselects.html identical to admin templates
- Remove global config fallback for database users in handlers
- Separate provider/rotation visibility: users only see their own, admin only global
- Update version to 0.99.38