feat: session busy indicator — daemon tracks mid-turn state (agent_start/settled), busy field on session rows + live broadcast; pulsing pip in sidebar and cards (265 web tests, daemon 95.4%)

daemon/hub.go

@@ -100,6 +100,7 @@ type SessionView struct {
 	Repo        *string `json:"repo"`
 	StartedAt   int64   `json:"startedAt"`
 	Online      bool    `json:"online"`
+	Busy        bool    `json:"busy"`
 	LastEventAt int64   `json:"lastEventAt"`
 }
 
@@ -342,6 +343,10 @@ type Hub struct {
 	agents map[string]*agentConn
 	webs   map[*webClient]struct{}
 
+	// busy tracks sessions mid-turn (agent_start without agent_settled),
+	// surfaced on session rows so the UI can show a live activity pulse.
+	busy map[string]bool
+
 	// SpawnStatus lets the API push spawn job snapshots to web clients.
 	SpawnStatus func() []SpawnJob
 
@@ -353,6 +358,7 @@ func NewHub(store *Store) *Hub {
 		store:  store,
 		agents: make(map[string]*agentConn),
 		webs:   make(map[*webClient]struct{}),
+		busy:   make(map[string]bool),
 		upgrader: websocket.Upgrader{
 			ReadBufferSize:  4096,
 			WriteBufferSize: 4096,
@@ -392,6 +398,7 @@ func (h *Hub) SessionsView() []SessionView {
 			LastEventAt: row.LastEventAt,
 		}
 		_, v.Online = h.agents[row.ID]
+		v.Busy = h.busy[row.ID]
 		out = append(out, v)
 	}
 	return out
@@ -607,6 +614,18 @@ func (h *Hub) handleEvent(f frame) {
 			log.Printf("hub: touch session %s: %v", f.sessionID, err)
 		}
 	}
+	// Track mid-turn state for the session-list activity pulse.
+	if f.typ == evAgentStart || f.typ == evAgentSettled {
+		busy := f.typ == evAgentStart
+		h.mu.Lock()
+		if h.busy[f.sessionID] != busy {
+			h.busy[f.sessionID] = busy
+			h.mu.Unlock()
+			go h.BroadcastSessionList()
+		} else {
+			h.mu.Unlock()
+		}
+	}
 	h.publishEvent(f.sessionID, f.seq, json.RawMessage(f.raw))
 }
 
@@ -624,6 +643,9 @@ func (h *Hub) unregister(ac *agentConn) {
 		if err := h.store.SetOnline(ac.sessionID, false); err != nil {
 			log.Printf("hub: mark offline %s: %v", ac.sessionID, err)
 		}
+		h.mu.Lock()
+		delete(h.busy, ac.sessionID)
+		h.mu.Unlock()
 	}
 	h.BroadcastSessionList()
 }

daemon/hub_extra_test.go

@@ -714,3 +714,34 @@ func TestWebResubscribeSplitsEventBatches(t *testing.T) {
 	_ = agent2.WriteJSON(map[string]any{"v": 1, "type": evMessageUpdate, "sessionId": "s2", "seq": 1, "ts": 11, "delta": "two"})
 	readBatch("s2") // event B must arrive as its own frame, never mixed with A's
 }
+
+func TestHubBusyFlagLifecycle(t *testing.T) {
+	ts, _, hub := newTestServerHub(t)
+	ws := dialAgent(t, ts)
+	defer ws.Close()
+	_ = ws.WriteJSON(helloFrame("busy-1"))
+	_ = readFrame(t, ws)
+	sendEv := func(typ string, seq int64) {
+		_ = ws.WriteJSON(map[string]any{
+			"v": 1, "sessionId": "busy-1", "seq": seq, "ts": 1, "type": typ,
+		})
+	}
+	sendEv("agent_start", 1)
+	waitFor(t, 3*time.Second, func() bool {
+		for _, s := range hub.SessionsView() {
+			if s.ID == "busy-1" {
+				return s.Busy
+			}
+		}
+		return false
+	})
+	sendEv("agent_settled", 2)
+	waitFor(t, 3*time.Second, func() bool {
+		for _, s := range hub.SessionsView() {
+			if s.ID == "busy-1" {
+				return !s.Busy
+			}
+		}
+		return false
+	})
+}