Add interactive Markdown checklist toggles in the ticket preview.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/ui/app.go

@@ -382,6 +382,23 @@ func (m Model) updateList(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		m.mode = ModeTimeEntries
 		return m, nil
 
+	case key.Matches(msg, m.keys.ChecklistNext):
+		m.clearStatus()
+		m.tickets.MoveChecklistDown()
+		return m, nil
+
+	case key.Matches(msg, m.keys.ChecklistPrev):
+		m.clearStatus()
+		m.tickets.MoveChecklistUp()
+		return m, nil
+
+	case key.Matches(msg, m.keys.Toggle):
+		m.clearStatus()
+		if err := m.toggleSelectedCheckbox(); err != nil {
+			m.setError(err)
+		}
+		return m, nil
+
 	case key.Matches(msg, m.keys.Down):
 		m.tickets.MoveDown()
 		return m, nil
@@ -985,6 +1002,52 @@ func (m *Model) applyStatus(st ticket.Status) error {
 	return nil
 }
 
+func (m *Model) toggleSelectedCheckbox() error {
+	t, ok := m.tickets.Selected()
+	if !ok {
+		return fmt.Errorf("no ticket selected")
+	}
+	boxes := ticket.ListCheckboxes(t.Description)
+	if len(boxes) == 0 {
+		return fmt.Errorf("no checkboxes in description")
+	}
+	checkIdx := m.tickets.ChecklistCursor
+	if checkIdx < 0 || checkIdx >= len(boxes) {
+		checkIdx = 0
+	}
+	newDesc, err := ticket.ToggleCheckbox(t.Description, checkIdx)
+	if err != nil {
+		return err
+	}
+	after := t
+	after.Description = newDesc
+	if err := m.exec.Do(&command.UpdateTicket{
+		Store:  m.store,
+		Before: t,
+		After:  after,
+	}); err != nil {
+		return err
+	}
+	ticketIdx := m.tickets.CursorIndex()
+	if err := m.reloadTickets(); err != nil {
+		return err
+	}
+	if ticketIdx < m.tickets.Len() {
+		m.tickets.Select(ticketIdx)
+	}
+	m.tickets.SetChecklistCursor(checkIdx)
+	state := "unchecked"
+	if !boxes[checkIdx].Checked {
+		state = "checked"
+	}
+	label := strings.TrimSpace(boxes[checkIdx].Text)
+	if label == "" {
+		label = fmt.Sprintf("#%d", checkIdx+1)
+	}
+	m.setStatus(fmt.Sprintf("%s %s", state, label))
+	return nil
+}
+
 func (m *Model) undo() error {
 	name := m.exec.LastUndoName()
 	if err := m.exec.Undo(); err != nil {