Add fleet groups, agent screenshots, deploy guards, and Crucible polish.

server/internal/api/websocket.go

@@ -47,8 +47,8 @@ func checkDashboardWSToken(r *http.Request) bool {
 }
 
 var upgrader = websocket.Upgrader{
-	ReadBufferSize:  4096,
-	WriteBufferSize: 4096,
+	ReadBufferSize:  512 * 1024,
+	WriteBufferSize: 512 * 1024,
 	CheckOrigin: func(r *http.Request) bool {
 		return true // Allow all origins for local use
 	},
@@ -246,6 +246,17 @@ func (h *WSHub) isAgentConnected(agentID string) bool {
 	return ok
 }
 
+// writeAgentJSON sends a message to a connected agent using the per-connection
+// write mutex. All post-auth outbound JSON must use this — never conn.WriteJSON
+// from the read loop, or commands and new_job messages can corrupt each other.
+func (h *WSHub) writeAgentJSON(agentID string, msg Message) error {
+	ac := h.getAgentConn(agentID)
+	if ac == nil {
+		return fmt.Errorf("agent %s not connected", agentID)
+	}
+	return ac.SendJSON(msg)
+}
+
 func (h *WSHub) SetPoolManager(manager *pool.Manager, defaultCfg pool.Config) {
 	h.mu.Lock()
 	h.poolManager = manager
@@ -826,12 +837,12 @@ func (h *WSHub) HandleAgentWS(w http.ResponseWriter, r *http.Request) {
 			if proxy != nil {
 				job := proxy.GetCurrentJob()
 				if job != nil {
-					conn.WriteJSON(Message{Type: "new_job", Payload: mustMarshal(job)})
+					_ = h.writeAgentJSON(agentID, Message{Type: "new_job", Payload: mustMarshal(job)})
 				} else {
-					conn.WriteJSON(Message{Type: "new_job", Payload: mustMarshal(map[string]string{"error": "no job available — pool connecting"})})
+					_ = h.writeAgentJSON(agentID, Message{Type: "new_job", Payload: mustMarshal(map[string]string{"error": "no job available — pool connecting"})})
 				}
 			} else {
-				conn.WriteJSON(Message{Type: "new_job", Payload: mustMarshal(map[string]string{"error": "pool connecting — retry shortly"})})
+				_ = h.writeAgentJSON(agentID, Message{Type: "new_job", Payload: mustMarshal(map[string]string{"error": "pool connecting — retry shortly"})})
 			}
 
 		case "log_tail":
@@ -899,6 +910,11 @@ func (h *WSHub) HandleDashboardWS(w http.ResponseWriter, r *http.Request) {
 	// Send initial data
 	agents, _ := h.db.ListAgents()
 	h.enrichAgentsCapabilities(agents)
+	for _, a := range agents {
+		if a != nil && h.isAgentConnected(a.ID) {
+			a.Status = "online"
+		}
+	}
 	stats, _ := h.db.GetFleetStats()
 
 	_ = dc.WriteJSON(Message{Type: "init", Payload: mustMarshal(map[string]interface{}{