Re-measured the revoke on the current stack (guard fix + fork lotus.4): the
SFU drops the sharer's tracks and EC's own button, the captured tracks and our
control bar all follow within ~2-4 s — the 30 s lag is gone. What remained was
that the button simply vanished with no explanation, so a call-lifetime hook
now toasts 'Screen sharing was turned off by a room admin.' (or the camera
variant) when a track ends while the room policy forbids it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA
