Add presence type selection for consultation attendance
This merge request adds attendance presence type selection for student consultation registration.
Implemented:
- added ONLINE / IN_PERSON attendance selection
- added toggle UI for choosing presence type
- locked the toggle when only one attendance type is available
- saved the selected presence type in consultation attendance
- displayed the selected presence type after registration
- updated the email/template display
- fixed null-safe rendering for one-time consultations
Note: This feature also requires the common-model database migration that adds the presence_type column to consultation_attendance. The common-model change was prepared locally, but I cannot push it because I do not have permission to push to the common-model repository.