Free the right pane for the lead once its inbox empties or task merges

internal/agents/leadtools.go

@@ -294,7 +294,8 @@ func (m *Manager) leadTools(l *live) []mcp.Tool {
 		tool("show",
 			"Point the human's right pane at a task, or at a project with no task: tabs are the tabs to put first, in order (the rest follow), and tab is the one to select. "+
 				"Tabs: transcript, changes, files, inbox (the task's open items), todo (the project's TODO.md); with only project_id, only todo shows anything. "+
-				"Omit both task_id and project_id to clear the pane. Refused while the human is working in the right pane.",
+				"Omit both task_id and project_id to clear the pane. "+
+				"Refused while the human is working in the right pane, unless what it shows is finished (a merged or discarded task, or an inbox tab with nothing left).",
 			`{"type": "object", "properties": {
 				"task_id": {"type": "string"},
 				"project_id": {"type": "string", "description": "Ignored when task_id is given."},
@@ -311,7 +312,17 @@ func (m *Manager) leadTools(l *live) []mcp.Tool {
 				focused := m.paneFocused[user.Login]
 				m.mu.Unlock()
 				if focused {
-					return "", fmt.Errorf("%w: the human is working in the right pane, so it was left as it is; tell them in chat instead", ErrConflict)
+					current, err := m.store.GetFocus(ctx, user.Login)
+					if err != nil {
+						return "", err
+					}
+					finished, err := m.paneFinished(ctx, current)
+					if err != nil {
+						return "", err
+					}
+					if finished == "" {
+						return "", fmt.Errorf("%w: the human is working in the right pane, so it was left as it is; tell them in chat instead", ErrConflict)
+					}
 				}
 				err = m.SetFocus(ctx, user.Login, f, leadActor(user.Login))
 				if err != nil {
@@ -359,6 +370,32 @@ func (m *Manager) SetFocus(ctx context.Context, login string, f api.Focus, actor
 	return m.store.SetFocus(ctx, login, f, actor)
 }
 
+const inboxEmptied = "has nothing left in its inbox"
+
+func (m *Manager) paneFinished(ctx context.Context, f api.Focus) (string, error) {
+	if f.TaskId == nil {
+		return "", nil
+	}
+	task, err := m.store.GetTask(ctx, *f.TaskId)
+	if err != nil {
+		return "", err
+	}
+	if task.Status != api.TaskStatusActive {
+		return "is " + string(task.Status), nil
+	}
+	if f.Tab != api.TabInbox {
+		return "", nil
+	}
+	items, err := m.store.ListInbox(ctx, store.InboxFilter{State: api.Open, TaskID: task.Id})
+	if err != nil {
+		return "", err
+	}
+	if len(items) > 0 {
+		return "", nil
+	}
+	return inboxEmptied, nil
+}
+
 func (m *Manager) SetPaneFocus(login string, focused bool) {
 	m.mu.Lock()
 	defer m.mu.Unlock()