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.

plugins/printers/frontend/views/PrinterForm.vue

@@ -505,14 +505,14 @@ onMounted(async () => {
       assetsApi.statuses.list(),
       vendorsApi.list({ perpage: 100 }),
       modelsApi.listAll({ category: 'Printer' }),
-      locationsApi.list({ perpage: 100 })
+      locationsApi.listAll()  // backend caps perpage at 100; page through all
     ])
 
     printerTypes.value = mtRes.data.data || []
     statuses.value = statusRes.data.data || []
     vendors.value = vendorRes.data.data || []
     models.value = allModels
-    locations.value = locRes.data.data || []
+    locations.value = locRes || []
 
     // Load printer if editing
     if (isEdit.value) {