feat: admin user management (create/search/role) and cluster resource monitoring

- Add POST /users endpoint for admin to create users with hashed passwords
- Add GET /users?search= with ILike search on email/firstName/lastName
- Add PATCH /users/:id/role for role assignment (user/admin)
- Return appCount per user in the users list
- Add GET /clusters/:id/resources for node, CPU, memory, pod monitoring
- Parse K8s node capacity/allocatable with CPU millicores and memory MiB helpers
- Frontend: admin users page with search bar, create form, role dropdown, app count
- Frontend: cluster resource panel with nodes table, CPU/memory bars, summary cards

backend/src/clusters/clusters.service.ts

@@ -348,4 +348,101 @@ export class ClustersService {
     this.logger.log(`Pool "${pool.name}" least-apps → cluster "${selected.name}" (${countMap.get(selected.id) || 0} apps)`);
     return selected;
   }
+
+  /**
+   * Get resource usage for a specific cluster — nodes, total CPU/memory, pod counts.
+   */
+  async getClusterResources(id: string): Promise<{
+    nodes: { name: string; status: string; roles: string; cpuCapacity: string; memoryCapacity: string; cpuAllocatable: string; memoryAllocatable: string; }[];
+    totalCpuCapacity: string;
+    totalMemoryCapacity: string;
+    totalCpuAllocatable: string;
+    totalMemoryAllocatable: string;
+    podCount: number;
+    nodeCount: number;
+    appCount: number;
+  }> {
+    const cluster = await this.findOne(id);
+
+    const kc = new k8s.KubeConfig();
+    kc.loadFromString(cluster.kubeconfig);
+    const coreApi = kc.makeApiClient(k8s.CoreV1Api);
+
+    try {
+      // Get nodes
+      const nodesRes = await coreApi.listNode();
+      const nodes = nodesRes.body.items.map((node) => {
+        const conditions = node.status?.conditions || [];
+        const readyCondition = conditions.find((c) => c.type === 'Ready');
+        const roles = Object.keys(node.metadata?.labels || {})
+          .filter((l) => l.startsWith('node-role.kubernetes.io/'))
+          .map((l) => l.replace('node-role.kubernetes.io/', ''))
+          .join(', ') || 'worker';
+
+        return {
+          name: node.metadata?.name || 'unknown',
+          status: readyCondition?.status === 'True' ? 'Ready' : 'NotReady',
+          roles,
+          cpuCapacity: node.status?.capacity?.cpu || '0',
+          memoryCapacity: node.status?.capacity?.memory || '0',
+          cpuAllocatable: node.status?.allocatable?.cpu || '0',
+          memoryAllocatable: node.status?.allocatable?.memory || '0',
+        };
+      });
+
+      // Total capacity
+      let totalCpuCap = 0;
+      let totalMemCap = 0;
+      let totalCpuAlloc = 0;
+      let totalMemAlloc = 0;
+      for (const node of nodes) {
+        totalCpuCap += this.parseCpuToMillicores(node.cpuCapacity);
+        totalMemCap += this.parseMemoryToMi(node.memoryCapacity);
+        totalCpuAlloc += this.parseCpuToMillicores(node.cpuAllocatable);
+        totalMemAlloc += this.parseMemoryToMi(node.memoryAllocatable);
+      }
+
+      // Get all pods count
+      const podsRes = await coreApi.listPodForAllNamespaces();
+      const podCount = podsRes.body.items.length;
+
+      // Get app count for this cluster
+      const appCountResult = await this.dataSource.query(
+        `SELECT COUNT(*) as count FROM applications WHERE "clusterId" = $1`,
+        [id],
+      );
+      const appCount = parseInt(appCountResult[0]?.count || '0', 10);
+
+      return {
+        nodes,
+        totalCpuCapacity: `${totalCpuCap}m`,
+        totalMemoryCapacity: `${totalMemCap.toFixed(0)}Mi`,
+        totalCpuAllocatable: `${totalCpuAlloc}m`,
+        totalMemoryAllocatable: `${totalMemAlloc.toFixed(0)}Mi`,
+        podCount,
+        nodeCount: nodes.length,
+        appCount,
+      };
+    } catch (err: any) {
+      this.logger.error(`Failed to get cluster resources for "${cluster.name}": ${err.message}`);
+      throw new BadRequestException(`Cannot fetch resources: ${err.message}`);
+    }
+  }
+
+  private parseCpuToMillicores(cpu: string): number {
+    if (!cpu || cpu === '0') return 0;
+    if (cpu.endsWith('n')) return parseFloat(cpu) / 1_000_000;
+    if (cpu.endsWith('u')) return parseFloat(cpu) / 1_000;
+    if (cpu.endsWith('m')) return parseFloat(cpu);
+    return parseFloat(cpu) * 1000;
+  }
+
+  private parseMemoryToMi(memory: string): number {
+    if (!memory || memory === '0') return 0;
+    if (memory.endsWith('Ki')) return parseFloat(memory) / 1024;
+    if (memory.endsWith('Mi')) return parseFloat(memory);
+    if (memory.endsWith('Gi')) return parseFloat(memory) * 1024;
+    if (memory.endsWith('Ti')) return parseFloat(memory) * 1024 * 1024;
+    return parseFloat(memory) / (1024 * 1024); // bytes
+  }
 }