feat(node-dashboard): add MVP dashboard API endpoint

- services/city-service: add /api/v1/nodes/{id}/dashboard endpoint
- services/city-service: add legacy /api/v1/node/dashboard?nodeId=...
- apps/web: update route.ts to use city-service first
- apps/web: fallback to node-registry if city-service fails

Response structure:
  node_id, name, kind, status, tags, agents_total,
  agents_online, uptime (null), metrics_available (false)

Closes TASK_PHASE_NODE_DASHBOARD_API_MVP

apps/web/src/app/api/node/dashboard/route.ts

@@ -1,25 +1,39 @@
 import { NextRequest, NextResponse } from 'next/server';
 
-const NODE_REGISTRY_URL = process.env.NODE_REGISTRY_URL || 'http://dagi-node-registry:9205';
+// Primary: city-service (has /api/v1/nodes/{id}/dashboard)
+// Fallback: node-registry (legacy, if configured)
+const CITY_SERVICE_URL = process.env.INTERNAL_API_URL || 'http://daarion-city-service:7001';
+const NODE_REGISTRY_URL = process.env.NODE_REGISTRY_URL || '';
 
 export async function GET(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url);
     const nodeId = searchParams.get('nodeId');
     
-    // Build URL - either specific node or self
-    const endpoint = nodeId 
-      ? `${NODE_REGISTRY_URL}/api/v1/nodes/${nodeId}/dashboard`
-      : `${NODE_REGISTRY_URL}/api/v1/nodes/self/dashboard`;
+    if (!nodeId) {
+      return NextResponse.json(
+        { error: 'nodeId query parameter is required' },
+        { status: 400 }
+      );
+    }
     
-    const response = await fetch(endpoint, {
-      headers: {
-        'Content-Type': 'application/json',
-      },
-      // Revalidate every 10 seconds
+    // Try city-service first (MVP dashboard)
+    const cityServiceEndpoint = `${CITY_SERVICE_URL}/api/v1/nodes/${nodeId}/dashboard`;
+    
+    let response = await fetch(cityServiceEndpoint, {
+      headers: { 'Content-Type': 'application/json' },
       next: { revalidate: 10 }
     });
     
+    // If city-service fails and node-registry is configured, try it as fallback
+    if (!response.ok && NODE_REGISTRY_URL) {
+      const nodeRegistryEndpoint = `${NODE_REGISTRY_URL}/api/v1/nodes/${nodeId}/dashboard`;
+      response = await fetch(nodeRegistryEndpoint, {
+        headers: { 'Content-Type': 'application/json' },
+        next: { revalidate: 10 }
+      });
+    }
+    
     if (!response.ok) {
       return NextResponse.json(
         { error: `Failed to fetch dashboard: ${response.status}` },
@@ -38,4 +52,3 @@ export async function GET(request: NextRequest) {
     );
   }
 }
-