Cover the three behaviours of PR #1792's forced MPV/VLC launch that had no
spec: a regular start made while a forced launch is pending is queued and
starts once the launch settled; the launch-position marker is skipped when
the page token changed before the launch settled, or while the position
saved; and the menu reports a failed launch only to the visit that asked
for it, while `startPending` holds the watched actions and the external row.
Each test fails when its branch is removed. The playback spec releases any
launch a failed test left open, since the launch chain is module state.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>