`subject_path_of` picks the group most of a workspace's tabs are in and hands
it back as a path. `display_name_of` then titles the window after its last
component. A custom group is a name, not a path, so a workspace grouped by
hand would have been titled `custom:work` — and one grouped as `work/urgent`
would have been chopped to `urgent`.
Only repo roots are counted now. A workspace grouped entirely by hand falls
through to a pane's cwd, which is a real path and is what the window was
titled after before any of this existed.
Claude-Session: https://claude.ai/code/session_01MS7VnqvGRtNTrJG9zxtz51