frontend phase 3: geography — addresses, map-pin picker & nurse coverage areas

Three domain services (mirroring the patients/nurse template): services/geography
(cached province→city→district lookups; Infinity staleTime + shared geographyKeys),
services/addresses (address book CRUD + set-primary; single-primary invariant), and
services/serviceAreas (coverage add/remove; areaExists dup-guard, districtId=null = whole city).

Four tested composites in src/components/geography: CascadingRegionSelect (drives the
cascade queries), AddressMapPicker (map-pin stand-in emitting real lat/lng), AddressForm,
AddressCard. Screens: customer address book (/addresses, reached from the profile hub) and
nurse coverage editor (/nurse/coverage, new sidebar tab, inline duplicate block + 409).

Adds geo/address/coverage i18n namespaces (both locales), location/delete/coverage icons,
ADDRESSES/NURSE_COVERAGE routes. Consumes the b4 geography-addresses contract; filed REQ-008
(accept the map pin on create/update) and REQ-009 (provinceId on CustomerAddressDto) for gaps.

Gate: npm run check + npm run test:ci (129, +17) + npm run build all green. A 5-dimension
adversarial review fixed 3 findings (map-marker RTL transform, page_size→pageSize pagination
casing, coverage districts-scope dead-end on district-less cities).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

client/src/services/serviceAreas/hooks/useAddServiceArea.ts

@@ -0,0 +1,19 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { serviceAreasApi } from '../apis';
+import { serviceAreaKeys } from '../keys';
+import type { AddServiceAreaInput } from '../types';
+
+/**
+ * Adds a coverage area, then invalidates the list. A duplicate `(cityId, districtId)` returns
+ * `409` — surfaced via `mutation.error` so the screen shows the inline "already covered" message
+ * (the client-side check is the fast path; this 409 is the belt-and-braces server truth).
+ */
+export function useAddServiceArea() {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: (input: AddServiceAreaInput) => serviceAreasApi.add(input),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: serviceAreaKeys.lists() });
+    },
+  });
+}