- Added functionality to update participant attendance status, allowing for 'excused' and 'cancelled' states. - Enhanced the participant model to include a default attendance status and validation for status values. - Updated participant routes to support status updates and integrated new status handling in the participant controller. - Modified the DiaryParticipantsPanel to visually indicate participant status and added a toggle for changing status. - Expanded localization files to include new keys for participant status, improving accessibility for users in both English and German.