Surface real API error on warranty refresh

Error messages nest at data.data.error.message; the warranty handlers read one
level too shallow so every failure showed a generic "failed". Read the correct
path (with fallbacks) so the actual reason shows - e.g. Dell's rate-limit
cooldown - and confirm the pulled coverage on a successful refresh.

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

frontend/src/views/warranty/WarrantiesList.vue

@@ -228,6 +228,14 @@ function openModal(item = null) {
 }
 function closeModal() { showModal.value = false; editing.value = null }
 
+// API errors nest the message at data.data.error.message (see error_response).
+function apiError(err, fallback) {
+  return err.response?.data?.data?.error?.message
+    || err.response?.data?.error?.message
+    || err.response?.data?.message
+    || fallback
+}
+
 async function save() {
   error.value = ''
   saving.value = true
@@ -241,7 +249,7 @@ async function save() {
     closeModal()
     loadData()
   } catch (err) {
-    error.value = err.response?.data?.error?.message || err.response?.data?.message || 'Failed to save'
+    error.value = apiError(err, 'Failed to save')
   } finally {
     saving.value = false
   }
@@ -253,16 +261,18 @@ async function deleteWarranty(w) {
     await warrantyApi.remove(w.warrantyid)
     loadData()
   } catch (err) {
-    alert(err.response?.data?.error?.message || 'Failed to delete')
+    alert(apiError(err, 'Failed to delete'))
   }
 }
 
 async function refresh(w) {
   try {
-    await warrantyApi.refresh(w.warrantyid)
+    const response = await warrantyApi.refresh(w.warrantyid)
     loadData()
+    const updated = response.data?.data
+    if (updated) alert(`Refreshed: ${updated.vendor} - ${updated.servicelevel || 'coverage'} ends ${updated.enddate || 'unknown'}`)
   } catch (err) {
-    alert(err.response?.data?.error?.message || err.response?.data?.message || 'Refresh failed')
+    alert(apiError(err, 'Refresh failed'))
   }
 }
 </script>