Previously forceSelfServerUnmuteUndeafen only ran on video-watch attempts and
after voice reconnects — so when an admin server-muted or server-deafened the
bot, it stayed muted/deafened for minutes (or forever if no streamer came on).
Add registerSelfVoiceStateGuard: a voiceStateUpdate listener that detects the
bot's own serverMute/serverDeaf transition to true and immediately re-issues
mute:false,deaf:false. Wired at client-ready in bootstrap.ts. Best-effort,
idempotent, never blocks the gateway.