Appointment gains:
- replaceServiceItems(): full replacement that unconditionally syncs the
legacy single serviceItem column. addServiceItem() only fills it when null,
which would leave stale service names in the four consumers that read
service_item (admin lists, public site, desktop app).
- currentServiceUuids(): input-order uuids, falling back to the single column
for appointments created before multi-service support.
- service_total_minutes / service_buffer_minutes (both nullable, NULL in slot
mode). slot_end - slot_start carries the number but cannot say whether it
was intentional, and a reserve entry has slot_start == slot_end so its
duration had nowhere to live.
Existing columns untouched: slot_start, slot_end, active_slot_key, is_reserve
verified unchanged via SHOW COLUMNS.
Task: docs/new_feture/taskes/task-00-service-mode-completion/
Slot-mode contract: unchanged (--group=slot-mode-frozen green)
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
