Starting a local recording left the idle 'Start Recording' chip on screen and never revealed 'Stop
Recording' — IsRecording raised its own notifications but not the output stage's, so the visibility
bindings were never re-evaluated. The visible chip's command then correctly refused to run (recording was
already in progress), which is the worst shape of bug: a dead button that looks live.
IsRecording and StreamStatus now call RaiseOutputStage(). The regression test asserts the NOTIFICATIONS,
not the property values — reading ShowEndRecordingAction directly passes either way, which is exactly how
this slipped through.
682 pass, 0 warnings.