feat(admin): build the last two screens, and pin spacing with a test

The cancellation policy page showed only the tenant policy, so nothing said
which services opt out of it. Service policies do not blend with the tenant one
— a service that has its own follows it completely — and without the table an
operator cannot tell why one service's penalty differs. It lists them with a
link to each service.

The waitlist had the matches endpoint and no way to reach it. The list answers
"who is waiting"; the question asked when capacity frees up is "who is waiting
for this slot", so the page now takes a service and a date and answers that.
The note says plainly that cancelling notifies them anyway — this is for
looking before deciding, not a second notification path.

Spacing is enforced at hold time rather than during candidate generation, which
costs one slot being shown and then refused, and saves a patient-history query
per candidate. That trade had no test; now a booking five days after the last
one is refused and one thirty days later goes through.

Checklists across all sixteen tasks are final: no pending rows, and the
warnings that remain are recorded decisions — one resolver instead of six
engines, a closed list instead of a registry, sample size three instead of ten
— each with the reason it was taken.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

assets/admin/hooks/useCancellation.ts

@@ -81,6 +81,26 @@ export function useCancelAppointment() {
   });
 }
 
+/**
+ * درخواست‌هایی که با یک زمان مشخص می‌خوانند — ابزار لحظهٔ آزاد شدن ظرفیت.
+ *
+ * جدا از فهرست است چون سؤال متفاوتی می‌پرسد: نه «چه کسی منتظر است» بلکه «چه کسی
+ * برای **این** وقت منتظر است».
+ */
+export function useWaitlistMatches(params: { serviceUuid: string; start: number; branchUuid?: string }) {
+  const query = useQuery({
+    queryKey: ['waitlist-matches', params],
+    queryFn: () =>
+      api.get<ApiResponse<WaitlistEntry[]>>(
+        `/api/v1/waitlist/matches?service_uuid=${params.serviceUuid}&start=${params.start}` +
+          (params.branchUuid ? `&branch_uuid=${params.branchUuid}` : ''),
+      ),
+    enabled: !!params.serviceUuid && params.start > 0,
+  });
+
+  return { matches: Array.isArray(query.data?.data) ? query.data.data : [], loading: query.isFetching };
+}
+
 export function useWaitlist(status?: string) {
   const qc = useQueryClient();
   const key = [...WAITLIST_KEY, status ?? ''];