Qt front door for cjm-substrate workflows — a direct port IN SPIRIT of cjm-workflow-hub-tui (DEC 61b46ae8, the c4b0d6e5 lane's last migration): the same collection-grouped source browse with stage-at-a-glance pipeline status and the same curation vocabulary (confirm / rename / refile / order / merge by title identity), whose pure spine it imports verbatim; the hub is a launcher, so under Qt it SPAWNS the stage apps as detached processes across their core envs instead of suspending into them. Born on-graph.