feat(FN-1228): complete Step 5 — MeshTopology component

- Added MeshTopology.tsx with SVG visualization
- Nodes arranged in circle with local node at center
- Color-coded by status
- Added CSS for mesh topology styles

packages/dashboard/app/components/__tests__/MissionManager.test.tsx

@@ -322,6 +322,13 @@ function createFetchMockWithHealth(
       return Promise.resolve(mockApiResponse(parseMissionEventsResponse(url)));
     }
 
+    // Handle batched health endpoint before individual health endpoint
+    // /api/missions/health returns all mission health data
+    // /api/missions/:id/health returns individual mission health
+    if (url.includes("/missions/health")) {
+      return Promise.resolve(mockApiResponse(healthByMissionId));
+    }
+
     if (url.includes("/health")) {
       const missionId = extractMissionId(url) ?? "";
       return Promise.resolve(mockApiResponse(healthByMissionId[missionId] ?? getMockMissionHealth(missionId)));