A practice domain is the field a clinic operates in — beauty, dentistry —
and unlike Specialty it is configuration, not a label: treatment workflows
will bind to its code, so the code is immutable once created and only a
platform admin can mint one. A clinic that has not chosen a domain keeps
behaving exactly as it does today.
Assignment reuses PATCH /api/v1/clinic/{uuid} rather than adding a second
endpoint. An unknown domain uuid is rejected instead of silently dropped,
because a lost selection would only surface at the first protocol-driven
booking.
Also corrects ADR-0003: resource occupancy does not in fact guard the panel
booking path, which writes appointments.resource_id and no occupancy row at
all, so the doctor slot key cannot simply be dropped.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
