- Add display_metrics JSON field to servers table
- Update server edit form with metric checkboxes
- ServerDetailController now uses server's display_metrics setting
- If no metrics selected - show all (backward compatibility)
- Removed hardcoded metric names from queries
- Remove server_id auto-resolution from validateAndGetToken()
- Links in edit.twig now use token instead of server_id
- Add agent_token retrieval in ServerController::edit()