fix(appointments): preload clinic + keep saved time on edit

The appointment-edit form opened with clinic/time blank even for
well-formed appointments because the pipeline never carried clinicId
end-to-end. Four-layer audit + fix:

1. APPOINTMENTS_QUERY now fetches clinicId + clinic { id clinicName }
   + doctor.fullName (was only doctor.id).
2. transformAppointments populates real clinicId + clinicName from the
   relation instead of faking clinicName=department.
3. Appointment type gets clinicId: string | null.
4. context-panel passes clinicId through to AppointmentForm's
   existingAppointment prop; form initial-states clinic from it.

Also on edit: if the saved timeSlot isn't in the fresh slot list
(past-slot filter, schedule change, clinic mismatch) we inject it as
"HH:MM (current)" so the dropdown displays the existing value instead
of looking cleared.

Historical appointments with clinicId=null on the platform still fall
through to the auto-select-from-slot logic; a maint backfill for those
is a separate task.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/call-desk/appointment-form.tsx

@@ -18,6 +18,7 @@ type ExistingAppointment = {
     doctorName: string;
     doctorId?: string;
     department: string;
+    clinicId?: string;
     reasonForVisit?: string;
     status: string;
 };
@@ -82,7 +83,11 @@ export const AppointmentForm = ({
     const [patientPhone, setPatientPhone] = useState(callerNumber ?? '');
     const [age, setAge] = useState('');
     const [gender, setGender] = useState<string | null>(null);
-    const [clinic, setClinic] = useState<string | null>(null);
+    // Preload clinic from the existing appointment when editing — so the
+    // select lands on the right branch instead of being empty and forcing
+    // the agent to re-pick. Only historical rows that predate clinicId
+    // persistence will fall through to the auto-select-from-slot logic.
+    const [clinic, setClinic] = useState<string | null>(existingAppointment?.clinicId ?? null);
     const [clinicItems, setClinicItems] = useState<Array<{ id: string; label: string }>>([]);
     const [department, setDepartment] = useState<string | null>(existingAppointment?.department ?? null);
     const [doctor, setDoctor] = useState<string | null>(existingAppointment?.doctorId ?? null);
@@ -113,14 +118,29 @@ export const AppointmentForm = ({
         ).then(slots => {
             // Filter by selected clinic — doctor may visit multiple branches
             const filtered = clinic ? slots.filter(s => s.clinicId === clinic) : slots;
-            setTimeSlotItems(filtered.map(s => ({ id: s.time, label: s.label })));
+            let items = filtered.map(s => ({ id: s.time, label: s.label }));
+
+            // In edit mode, the saved timeSlot may have been filtered out
+            // (past-slot filter, schedule change, clinic mismatch). Inject
+            // it as a synthetic option so the dropdown still shows the
+            // existing value — otherwise the agent sees a cleared field
+            // and assumes the save-time was lost.
+            if (timeSlot && !items.some(i => i.id === timeSlot)) {
+                items = [{ id: timeSlot, label: `${timeSlot} (current)` }, ...items];
+            }
+
+            setTimeSlotItems(items);
             // Auto-select clinic from the slot's clinic only if no clinic chosen
             if (filtered.length === 0 && slots.length > 0 && !clinic) {
                 setClinic(slots[0].clinicId);
-                setTimeSlotItems(slots.filter(s => s.clinicId === slots[0].clinicId).map(s => ({ id: s.time, label: s.label })));
+                const autoItems = slots.filter(s => s.clinicId === slots[0].clinicId).map(s => ({ id: s.time, label: s.label }));
+                if (timeSlot && !autoItems.some(i => i.id === timeSlot)) {
+                    autoItems.unshift({ id: timeSlot, label: `${timeSlot} (current)` });
+                }
+                setTimeSlotItems(autoItems);
             }
         }).catch(() => setTimeSlotItems([]));
-    }, [doctor, date, clinic]);
+    }, [doctor, date, clinic, timeSlot]);
 
     // Availability state
     const [bookedSlots, setBookedSlots] = useState<string[]>([]);