- Updated admin panel keyboard to match admin_panel.py handlers
- Changed registration button logic: show only for unregistered non-admins
- Added missing methods to IBotController interface
- Updated get_main_keyboard to accept is_registered parameter
- Simplified admin panel structure with proper callback routing
- Removed test callback button from production UI
- Created ADMIN_PANEL_STRUCTURE.md and ADMIN_PANEL_TESTING.md documentation
