fix: OpenSearch status field mismatch, adopt RouteFlow flows prop

Fix admin OpenSearch page always showing "Disconnected" by aligning
frontend field names (reachable/nodeCount/host) with backend DTO.

Update design system to v0.1.10 and adopt the new multi-flow RouteFlow
API — error-handler nodes now render as labeled segments with error
variant instead of relying on legacy auto-separation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/api/queries/admin/opensearch.ts

@@ -5,11 +5,11 @@ import { useRefreshInterval } from '../use-refresh-interval';
 // ── Types ──────────────────────────────────────────────────────────────
 
 export interface OpenSearchStatus {
-  connected: boolean;
+  reachable: boolean;
   clusterHealth: string;
   version: string | null;
-  numberOfNodes: number;
-  url: string;
+  nodeCount: number;
+  host: string;
 }
 
 export interface PipelineStats {