feat(explorer): mission-control resilience, ops token labels, and CI validate

Add SSE reconnect with backoff, fallback REST polling, visibility-aware refresh,
extended token-list labels on operations pages, validate-on-pr workflow, and smoke coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/common/TokenListSurfaceNote.tsx

@@ -0,0 +1,13 @@
+import { TOKEN_LIST_SURFACE_LABELS, type TokenListSurface } from '@/services/api/tokenListSurfaces'
+
+interface TokenListSurfaceNoteProps {
+  surface?: TokenListSurface
+  className?: string
+}
+
+export default function TokenListSurfaceNote({
+  surface = 'extended',
+  className = 'text-sm text-gray-600 dark:text-gray-400',
+}: TokenListSurfaceNoteProps) {
+  return <p className={className}>{TOKEN_LIST_SURFACE_LABELS[surface]}</p>
+}