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/pages/Admin/OpenSearchAdminPage.tsx

@@ -23,10 +23,10 @@ export default function OpenSearchAdminPage() {
       <h2 style={{ marginBottom: '1rem' }}>OpenSearch Administration</h2>
 
       <div style={{ display: 'flex', gap: '1rem', marginBottom: '1.5rem', flexWrap: 'wrap' }}>
-        <StatCard label="Status" value={status?.connected ? 'Connected' : 'Disconnected'} accent={status?.connected ? 'success' : 'error'} />
+        <StatCard label="Status" value={status?.reachable ? 'Connected' : 'Disconnected'} accent={status?.reachable ? 'success' : 'error'} />
         <StatCard label="Health" value={status?.clusterHealth ?? '—'} accent={status?.clusterHealth === 'green' ? 'success' : 'warning'} />
         <StatCard label="Version" value={status?.version ?? '—'} />
-        <StatCard label="Nodes" value={status?.numberOfNodes ?? 0} />
+        <StatCard label="Nodes" value={status?.nodeCount ?? 0} />
       </div>
 
       {pipeline && (