Add refresh-cluster button to detect new Proxmox cluster members

When new nodes are added to a Proxmox cluster after Pulse was
initially configured, they weren't showing up in Settings. The
existing "Refresh" button only triggered network discovery, not
cluster membership re-detection.

Changes:
- Add POST /api/config/nodes/{id}/refresh-cluster endpoint
- Add "Refresh" button in cluster node panel in Settings
- Re-detect cluster membership and update stored endpoints

Related to #799

frontend-modern/src/api/nodes.ts

@@ -58,4 +58,22 @@ export class NodesAPI {
       method: 'POST',
     });
   }
+
+  static async refreshClusterNodes(nodeId: string): Promise<{
+    status: string;
+    clusterName?: string;
+    oldNodeCount?: number;
+    newNodeCount?: number;
+    nodesAdded?: number;
+    clusterNodes?: Array<{
+      nodeId: string;
+      nodeName: string;
+      host: string;
+      online: boolean;
+    }>;
+  }> {
+    return apiFetchJSON(`${this.baseUrl}/${nodeId}/refresh-cluster`, {
+      method: 'POST',
+    });
+  }
 }

frontend-modern/src/components/Settings/ConfiguredNodeTables.tsx

@@ -28,6 +28,7 @@ interface PveNodesTableProps {
   onTestConnection: (nodeId: string) => void;
   onEdit: (node: NodeConfigWithStatus) => void;
   onDelete: (node: NodeConfigWithStatus) => void;
+  onRefreshCluster?: (nodeId: string) => void;
 }
 
 type StatusMeta = { dotClass: string; label: string; labelClass: string };
@@ -381,12 +382,29 @@ export const PveNodesTable: Component<PveNodesTableProps> = (props) => {
                               </For>
                             </div>
                           </Show>
-                          <p class="flex items-center gap-1 text-[0.7rem] text-gray-600 dark:text-gray-400">
+                          <div class="flex items-center justify-between gap-2">
-                            <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <p class="flex items-center gap-1 text-[0.7rem] text-gray-600 dark:text-gray-400">
-                              <path d="M5 12h14M12 5l7 7-7 7" />
+                              <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
-                            </svg>
+                                <path d="M5 12h14M12 5l7 7-7 7" />
-                            Automatic failover enabled between cluster nodes
+                              </svg>
-                          </p>
+                              Automatic failover enabled
+                            </p>
+                            <Show when={props.onRefreshCluster}>
+                              <button
+                                type="button"
+                                onClick={() => props.onRefreshCluster?.(node.id)}
+                                class="flex items-center gap-1 px-2 py-1 text-[0.65rem] font-medium text-gray-600 hover:text-gray-800 dark:text-gray-400 dark:hover:text-gray-200 bg-white dark:bg-gray-700 border border-gray-300 dark:border-gray-600 rounded hover:bg-gray-50 dark:hover:bg-gray-600 transition-colors"
+                                title="Re-detect cluster membership (use if nodes were added to the Proxmox cluster)"
+                              >
+                                <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                                  <polyline points="23 4 23 10 17 10"></polyline>
+                                  <polyline points="1 20 1 14 7 14"></polyline>
+                                  <path d="M3.51 9a9 9 0 0 1 14.85-3.36L23 10M1 14l4.64 4.36A9 9 0 0 0 20.49 15"></path>
+                                </svg>
+                                Refresh
+                              </button>
+                            </Show>
+                          </div>
                         </div>
                       </Show>
                     </div>

frontend-modern/src/components/Settings/Settings.tsx

@@ -2208,6 +2208,26 @@ const Settings: Component<SettingsProps> = (props) => {
     }
   };
 
+  const refreshClusterNodes = async (nodeId: string) => {
+    try {
+      notificationStore.info('Refreshing cluster membership...', 2000);
+      const result = await NodesAPI.refreshClusterNodes(nodeId);
+      if (result.status === 'success') {
+        if (result.nodesAdded && result.nodesAdded > 0) {
+          showSuccess(`Found ${result.nodesAdded} new node(s) in cluster "${result.clusterName}"`);
+        } else {
+          showSuccess(`Cluster "${result.clusterName}" membership verified (${result.newNodeCount} nodes)`);
+        }
+        // Refresh nodes list to show updated cluster info
+        await loadNodes();
+      } else {
+        throw new Error('Failed to refresh cluster');
+      }
+    } catch (error) {
+      showError(error instanceof Error ? error.message : 'Failed to refresh cluster membership');
+    }
+  };
+
   const checkForUpdates = async () => {
     setCheckingForUpdates(true);
     try {
@@ -2800,6 +2820,7 @@ const Settings: Component<SettingsProps> = (props) => {
                                 setShowNodeModal(true);
                               }}
                               onDelete={requestDeleteNode}
+                              onRefreshCluster={refreshClusterNodes}
                             />
                           </Show>
 

internal/api/config_handlers.go

@@ -2318,6 +2318,123 @@ func (h *ConfigHandlers) HandleDeleteNode(w http.ResponseWriter, r *http.Request
 	json.NewEncoder(w).Encode(map[string]string{"status": "success"})
 }
 
+// HandleRefreshClusterNodes re-detects cluster membership and updates endpoints
+// This handles the case where nodes are added to a Proxmox cluster after initial configuration
+func (h *ConfigHandlers) HandleRefreshClusterNodes(w http.ResponseWriter, r *http.Request) {
+	// Prevent modifications in mock mode
+	if mock.IsMockEnabled() {
+		http.Error(w, "Cannot refresh cluster in mock mode", http.StatusForbidden)
+		return
+	}
+
+	// Path format: /api/config/nodes/{id}/refresh-cluster
+	path := strings.TrimPrefix(r.URL.Path, "/api/config/nodes/")
+	path = strings.TrimSuffix(path, "/refresh-cluster")
+	nodeID := path
+
+	if nodeID == "" {
+		http.Error(w, "Node ID required", http.StatusBadRequest)
+		return
+	}
+
+	// Parse node ID
+	parts := strings.Split(nodeID, "-")
+	if len(parts) != 2 {
+		http.Error(w, "Invalid node ID", http.StatusBadRequest)
+		return
+	}
+
+	nodeType := parts[0]
+	index := 0
+	if _, err := fmt.Sscanf(parts[1], "%d", &index); err != nil {
+		http.Error(w, "Invalid node ID", http.StatusBadRequest)
+		return
+	}
+
+	// Only PVE nodes can have clusters
+	if nodeType != "pve" {
+		http.Error(w, "Only PVE nodes can be cluster members", http.StatusBadRequest)
+		return
+	}
+
+	if index >= len(h.config.PVEInstances) {
+		http.Error(w, "Node not found", http.StatusNotFound)
+		return
+	}
+
+	pve := &h.config.PVEInstances[index]
+
+	// Create client config for cluster detection
+	clientConfig := config.CreateProxmoxConfig(pve)
+
+	// Force cluster re-detection (ignore existing endpoints)
+	isCluster, clusterName, clusterEndpoints := detectPVECluster(clientConfig, pve.Name, pve.ClusterEndpoints)
+
+	if !isCluster {
+		http.Error(w, "Node is not part of a cluster", http.StatusBadRequest)
+		return
+	}
+
+	if len(clusterEndpoints) == 0 {
+		http.Error(w, "Could not detect cluster nodes", http.StatusInternalServerError)
+		return
+	}
+
+	oldEndpointCount := len(pve.ClusterEndpoints)
+	newEndpointCount := len(clusterEndpoints)
+
+	// Update cluster info
+	pve.IsCluster = true
+	if clusterName != "" && !strings.EqualFold(clusterName, "unknown cluster") {
+		pve.ClusterName = clusterName
+	}
+	pve.ClusterEndpoints = clusterEndpoints
+
+	// Save configuration
+	if err := h.persistence.SaveNodesConfig(h.config.PVEInstances, h.config.PBSInstances, h.config.PMGInstances); err != nil {
+		log.Error().Err(err).Msg("Failed to save nodes configuration after cluster refresh")
+		http.Error(w, "Failed to save configuration", http.StatusInternalServerError)
+		return
+	}
+
+	log.Info().
+		Str("instance", pve.Name).
+		Str("cluster", pve.ClusterName).
+		Int("old_endpoints", oldEndpointCount).
+		Int("new_endpoints", newEndpointCount).
+		Msg("Refreshed cluster membership")
+
+	// Reload monitor with new configuration
+	if h.reloadFunc != nil {
+		if err := h.reloadFunc(); err != nil {
+			log.Error().Err(err).Msg("Failed to reload monitor after cluster refresh")
+			// Don't fail the request, config was saved successfully
+		}
+	}
+
+	// Broadcast update to refresh frontend
+	if h.wsHub != nil {
+		h.wsHub.BroadcastMessage(websocket.Message{
+			Type: "nodes_updated",
+			Data: map[string]interface{}{
+				"nodeType": "pve",
+				"action":   "cluster_refresh",
+			},
+			Timestamp: time.Now().Format(time.RFC3339),
+		})
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"status":        "success",
+		"clusterName":   pve.ClusterName,
+		"oldNodeCount":  oldEndpointCount,
+		"newNodeCount":  newEndpointCount,
+		"nodesAdded":    newEndpointCount - oldEndpointCount,
+		"clusterNodes":  clusterEndpoints,
+	})
+}
+
 func (h *ConfigHandlers) triggerPVEHostCleanup(host string) {
 	client := tempproxy.NewClient()
 	if client == nil || !client.IsAvailable() {

internal/api/router.go

@@ -310,9 +310,11 @@ func (r *Router) setupRoutes() {
 		case http.MethodDelete:
 			RequireAdmin(r.configHandlers.config, RequireScope(config.ScopeSettingsWrite, r.configHandlers.HandleDeleteNode))(w, req)
 		case http.MethodPost:
-			// Handle test endpoint
+			// Handle test endpoint and refresh-cluster endpoint
 			if strings.HasSuffix(req.URL.Path, "/test") {
 				RequireAdmin(r.configHandlers.config, RequireScope(config.ScopeSettingsWrite, r.configHandlers.HandleTestNode))(w, req)
+			} else if strings.HasSuffix(req.URL.Path, "/refresh-cluster") {
+				RequireAdmin(r.configHandlers.config, RequireScope(config.ScopeSettingsWrite, r.configHandlers.HandleRefreshClusterNodes))(w, req)
 			} else {
 				http.Error(w, "Not found", http.StatusNotFound)
 			}