Previously, voice cleanup only happened in finalizeDisconnect after a
5-second grace period, and only when ALL connections closed. If a user
was logged in on multiple devices and closed the one in voice, the
voice state was never cleaned up — creating a permanent ghost in the
channel sidebar.
Now removeConnection checks if the closing socket is the voice-active
one (tracked via voiceWs map) and immediately cleans up voice state,
broadcasts the leave event, and notifies remaining tabs.
Jannis Braun
f90cf91760