- Extract the shared New Session action into WorkspacesService.startSession
(sidebar button and workspace browser both delegate; recent-Workspace
targeting and the no-workspace clear live in one place).
- Fold the chip-insertion transaction shared by insert-ref and paste-upgrade
into one InputMachine helper.
- Share the fixture's session-not-found guard across the sessionId-addressed
catalog routes.
- Drop the AppFrame baselines-ready loading gate (user ruling: the bare
status line reads worse than the shell's own pending rendering); both
column occupants mount from first paint.