Fix location dropdowns silently truncating at the 100-row backend cap

The backend clamps perpage to MAX_PAGE_SIZE (100), so location selectors that requested a large page received only the first page and still got a 200. Late-alphabet locations (past ~C5W) simply went missing from every module's dropdown, and no error surfaced.

Add locationsApi.listAll, which pages through the full set via fetchAllPages, matching the established machines/printers pattern, and switch every location selector consumer to it.

frontend/src/api/index.js

@@ -273,6 +273,12 @@ export const locationsApi = {
   list(params = {}) {
     return api.get('/locations', { params })
   },
+  // Every location, paged past the backend's 100-row cap. Location selector
+  // dropdowns must use this: list() with a large perpage is clamped to 100 and
+  // still returns a success response, so the tail simply goes missing.
+  listAll(params = {}) {
+    return fetchAllPages('/locations', params)
+  },
   get(id) {
     return api.get(`/locations/${id}`)
   },