fix(#1741): resolve Ctrl+K key binding conflict in session browser

Ctrl+K was bound to both Up navigation and CopyID in the session
browser dialog. Since Up was matched first in the Update switch,
the CopyID handler was unreachable.

Reassign CopyID to Ctrl+Y (vim/emacs yank convention), keeping
Ctrl+K for Up navigation consistent with the command palette.

Assisted-By: cagent

Author: aheritier

pkg/tui/dialog/session_browser.go

@@ -76,7 +76,7 @@ func NewSessionBrowserDialog(sessions []session.Summary) Dialog {
 			Escape:     key.NewBinding(key.WithKeys("esc")),
 			Star:       key.NewBinding(key.WithKeys("ctrl+s")),
 			FilterStar: key.NewBinding(key.WithKeys("ctrl+f")),
-			CopyID:     key.NewBinding(key.WithKeys("ctrl+k")),
+			CopyID:     key.NewBinding(key.WithKeys("ctrl+y")),
 		},
 		openedAt: time.Now(),
 	}
@@ -290,7 +290,7 @@ func (d *sessionBrowserDialog) View() string {
 		AddSeparator().
 		AddContent(idFooter).
 		AddSpace().
-		AddHelpKeys("↑/↓", "navigate", "ctrl+s", "star", "ctrl+f", filterDesc, "ctrl+k", "copy id", "enter", "load", "esc", "close").
+		AddHelpKeys("↑/↓", "navigate", "ctrl+s", "star", "ctrl+f", filterDesc, "ctrl+y", "copy id", "enter", "load", "esc", "close").
 		Build()
 
 	return styles.DialogStyle.Width(dialogWidth).Render(content)

pkg/tui/dialog/session_browser_test.go

@@ -87,6 +87,12 @@ func TestSessionBrowserNavigationWithCtrl(t *testing.T) {
 	updated, _ = d.Update(ctrlK)
 	d = updated.(*sessionBrowserDialog)
 	require.Equal(t, 0, d.selected, "selection should be 0 after ctrl+k")
+
+	// Verify ctrl+y is bound to CopyID and doesn't collide with Up.
+	// We only assert key matching here to avoid clipboard side-effects in tests.
+	ctrlY := tea.KeyPressMsg{Code: 'y', Mod: tea.ModCtrl}
+	require.True(t, key.Matches(ctrlY, d.keyMap.CopyID), "ctrl+y should match keyMap.CopyID")
+	require.False(t, key.Matches(ctrlY, d.keyMap.Up), "ctrl+y should not match keyMap.Up")
 }
 
 func TestSessionBrowserViewShowsSelection(t *testing.T) {