chore(bot): log an explicit line when the broadcast auto-starts on join

Makes the Go-Live auto-start verifiable from the container logs (the reviewer
flagged that a successful broadcast left no log record), alongside the existing
loud failure log.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

bot/src/broadcast.ts

@@ -72,7 +72,10 @@ export async function autoStartBroadcast(
     try {
       if (streamer.isActive()) return true;
       await streamer.start(ctx);
-      if (streamer.isActive()) return true;
+      if (streamer.isActive()) {
+        console.log("🔴 [broadcast] auto-started on voice join (Go Live)");
+        return true;
+      }
       console.error(
         `[broadcast] auto-start attempt ${attempt}/${attempts} did not go live`,
       );