If someone is ALREADY sharing screen / camera on when the bot joins the
channel, no voiceStateUpdate with streaming:true fires for them, so the
bot never sent STREAM_WATCH and missed their video entirely. trackChannel
now scans channel.members and starts a watch for anyone already streaming
(ignoring the bot itself and non-streamers). Idempotent: startStreamWatch
no-ops if a watch already exists. +2 tests (9/9 in videoRecorder).
asepharyana
87f1f8be8d