refactor(pricing): make the service the only price source

Price lists, annual tariffs and per-branch price overrides each answered
"what does this service cost?" differently, so a single date could carry
several answers and nobody could say which one was right. Price now lives
only on ServiceItem.price_rials, edited from the services page.

- drop PriceList/PriceListItem, their repositories and the seven
  /api/v1/price-list(s) endpoints; PricingController keeps only quote and
  the appointment price snapshot
- drop Tariff, TariffRepository, TariffService and the two
  /service-items/{uuid}/tariffs endpoints; creating or repricing a service
  no longer upserts a current-year tariff
- drop price_rials from ServiceBranchOverride; the entity stays for its
  duration columns, which DurationCalculator and ServiceSelectionValidator
  still read
- InvoiceService reads the item price directly
- PricingEngine collapses to a single source; breakdown.sources always
  reports service_item, keeping the response contract intact
- remove the price-lists admin page, its route and settings-menu entry, the
  tariff modal and the service detail tariffs tab; useAppointmentInvoice
  moves to its own hook file

Migration drops price_lists, price_list_items, service_tariffs and the
override price column.

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

assets/admin/hooks/useAppointmentInvoice.ts

@@ -0,0 +1,38 @@
+import { useQuery } from '@tanstack/react-query';
+import { api, type ApiResponse } from '../lib/api';
+
+export interface PriceSnapshotLine {
+  label: string;
+  rials: number;
+  kind?: string;
+}
+
+export interface PriceSnapshot {
+  base_rials: number;
+  items_rials: number;
+  discount_rials: number;
+  insurance_base_rials: number;
+  insurance_supplementary_rials: number;
+  tax_rials: number;
+  final_rials: number;
+  deposit_rials: number;
+  created_at?: number;
+  breakdown: {
+    discounts: PriceSnapshotLine[];
+    sources: Record<string, unknown>;
+  };
+}
+
+/** فاکتور یک نوبت — همان اعداد لحظهٔ ثبت، حتی اگر قیمت سرویس بعداً عوض شده باشد. */
+export function useAppointmentInvoice(appointmentUuid: string | undefined) {
+  const query = useQuery({
+    queryKey: ['appointment-invoice', appointmentUuid],
+    queryFn: () =>
+      api.get<ApiResponse<PriceSnapshot>>(`/api/v1/appointment/${appointmentUuid}/price-snapshot`),
+    enabled: !!appointmentUuid,
+    // نوبتِ بدون فاکتور ۴۰۴ می‌دهد و آن خطا نیست، یعنی «هنوز ثبت نشده».
+    retry: false,
+  });
+
+  return { invoice: query.data?.data, loading: query.isLoading, missing: query.isError };
+}