iOS gives a page one audible video at a time. Start a second one with
sound and the system pauses the first, so on an iPhone a split of two
showed one panel playing and one stopped -- the feed-wide unmute set every
panel audible, and the panels then took the audio session from each other
in turn.
Muted video carries no such limit, so where the rule applies exactly one
panel keeps its sound and the rest keep their picture: four pictures moving
is what the split is for, and four audio tracks at once was never the
point. The sound follows whichever panel is asked for it, and a panel the
system stopped on the way is started again.
Nothing in the platform announces the rule, and by the time the symptom
shows -- a video we started, stopped by something that isn't us -- a panel
has already died, so it is read off the device rather than discovered.
Everywhere else nothing changes: panels keep their own sound.
No iPhone here, so the rule is installed into Chromium and the real feed is
driven through it. The last check breaks it on purpose -- unmuting every
panel by hand does stop one -- so the simulation can't quietly become a
no-op. Against the code before this commit the test fails seven checks,
showing exactly what was reported: both panels unmuted, the first paused.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MPZFnNdHbPGDTqQUNiE4ZN
b8a51d9ee2