The branch list's click goes through Tree::pick_ref, which clears the
look like every other pick; the test covers file, commit, side,
branch and remote picks. The test window installs the app's menus
first, as tool_root does: Windows and Linux draw the menu bar in the
window and panicked on an empty one.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
