Let the lead reorder tabs on what the pane already shows

internal/agents/lead_test.go

@@ -2,6 +2,7 @@ package agents_test
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 	"testing"
 	"time"
@@ -89,6 +90,22 @@ func TestLeadSignalsAndShow(t *testing.T) {
 		t.Fatalf("focus moved while the pane was focused: %+v", f)
 	}
 
+	_, err = m.MessageLead(e.ctx, e.user, "Call the show tool with task_id "+e.task.Id+", tabs [\"inbox\", \"changes\"] and tab \"inbox\". Then say done.", "", nil)
+	if err != nil {
+		t.Fatalf("message lead: %v", err)
+	}
+	e.waitFor("show of what is already shown", func(ev api.Event) bool {
+		return ev.Kind == "agent.tool_result" && ev.Owner != nil && strings.Contains(fmt.Sprint(ev.Payload), "Already shown")
+	})
+	e.waitFor("lead idle after already-shown show", leadIdle)
+	f, err = e.store.GetFocus(e.ctx, login)
+	if err != nil {
+		t.Fatalf("get focus: %v", err)
+	}
+	if f.Tab != api.TabInbox || !slices.Equal(f.Tabs, []api.TaskTab{api.TabInbox, api.TabChanges}) {
+		t.Fatalf("tabs not reordered on the shown tab: %+v", f)
+	}
+
 	err = e.store.WithdrawItem(e.ctx, created[len(created)-1].Payload["id"].(string))
 	if err != nil {
 		t.Fatalf("withdraw report: %v", err)

internal/agents/leadtools.go

@@ -295,7 +295,8 @@ func (m *Manager) leadTools(l *live) []mcp.Tool {
 			"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), project (the project's dashboard: its active tasks and its TODO.md items); with only project_id, only project shows anything. "+
 				"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).",
+				"If the pane already shows that task (or project) on that tab, only the tab order changes and you are told so, even while the human is working in the pane. "+
+				"Otherwise 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."},
@@ -308,14 +309,24 @@ func (m *Manager) leadTools(l *live) []mcp.Tool {
 				if err != nil {
 					return "", err
 				}
+				current, err := m.store.GetFocus(ctx, user.Login)
+				if err != nil {
+					return "", err
+				}
+				if sameView(current, f) {
+					if slices.Equal(current.Tabs, f.Tabs) {
+						return "Already shown: the right pane shows that now, so nothing changed.", nil
+					}
+					err = m.SetFocus(ctx, user.Login, f, leadActor(user.Login))
+					if err != nil {
+						return "", err
+					}
+					return "Already shown on that tab; the tab order was updated.", nil
+				}
 				m.mu.Lock()
 				focused := m.paneFocused[user.Login]
 				m.mu.Unlock()
 				if focused {
-					current, err := m.store.GetFocus(ctx, user.Login)
-					if err != nil {
-						return "", err
-					}
 					finished, err := m.paneFinished(ctx, current)
 					if err != nil {
 						return "", err
@@ -370,6 +381,17 @@ func (m *Manager) SetFocus(ctx context.Context, login string, f api.Focus, actor
 	return m.store.SetFocus(ctx, login, f, actor)
 }
 
+func sameView(a, b api.Focus) bool {
+	if a.Tab != b.Tab {
+		return false
+	}
+	at, bt := deref(a.TaskId), deref(b.TaskId)
+	if at != "" || bt != "" {
+		return at == bt
+	}
+	return deref(a.ProjectId) == deref(b.ProjectId)
+}
+
 const inboxEmptied = "has nothing left in its inbox"
 
 func (m *Manager) paneFinished(ctx context.Context, f api.Focus) (string, error) {