Warranty polish: hero badges everywhere, search/pagination, re-check, shared apiError

- Shared utils/apiError.js reads the correct nested error message (with
  fallbacks); swept 37 views/components off the shallow path so real backend
  messages (e.g. in-use 409s) surface instead of generic "Failed".
- useWarrantyBadge composable: warranty hero status/end-date badge now on PC,
  equipment, printer, and network detail heroes (one shared fetch feeds the
  badge + the WarrantyPanel).
- Warranties list: client-side search (vendor/level/tag/asset) + pagination;
  truncate long service levels so they stop blowing out the table width.
- "Re-check all" button + POST /warranty/sync/dell?all=true to re-pull dated
  Dell warranties, not just missing ones.
- Deprecate the standalone pxe-images/warranty_sync.py in favor of the plugin.

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

frontend/src/utils/apiError.js

@@ -0,0 +1,9 @@
+// Extract a human-readable message from an API error. The backend nests the
+// message at data.data.error.message (see error_response); older call sites read
+// shallower paths, so try them all before falling back.
+export function apiError(err, fallback = 'Something went wrong') {
+  return err?.response?.data?.data?.error?.message
+    || err?.response?.data?.error?.message
+    || err?.response?.data?.message
+    || fallback
+}