Tie playback to the listener and keep the panel's view live

Four things people hit while using the panel:

- The bot could be sent into a channel the requester was not in, and
  playback could be started from nowhere. Playback now follows the
  listener (REQUIRE_LISTENER, on by default), and the voice row shows
  where you and the bot are instead of offering a free channel picker.
- Voice presence only refreshed on reload, because the SDK updates
  channel participants without emitting an event. The socket now watches
  that view and pushes changes.
- The bot left the channel whenever the queue ran dry. It now leaves only
  after the last person does, EMPTY_TIMEOUT_SECONDS later (120 by
  default), and stays put while anyone is still listening.
- A search that yielded nothing said nothing: yt-dlp can exit 0 with an
  empty result, so that case now reports the reason (or "nothing found"),
  and searches are logged with their result count.

The queue moved under the player so search owns the left column, and
elapsed time no longer renders as "LIVE" — formatDuration treated 0 as a
live stream, which also affected the chat's progress bar.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/core/manager.ts

@@ -141,10 +141,22 @@ export class MusicManager extends EventEmitter<ManagerEvents> {
     const player = this.getOrCreate(serverId);
     if (options.textChannelId) player.textChannelId = options.textChannelId;
 
-    const target = options.voiceChannelId
-      ? this.chat.getVoiceChannel(options.voiceChannelId)
-      : (this.chat.findUserVoiceChannel(serverId, userId) ??
-        (player.voiceChannelId ? this.chat.getVoiceChannel(player.voiceChannelId) : null));
+    const listening = this.chat.findUserVoiceChannel(serverId, userId);
+
+    if (config.REQUIRE_LISTENER) {
+      // Music follows the listener: you cannot push the bot into a channel you
+      // are not sitting in, and you cannot start playback from nowhere.
+      if (!listening) throw new UserFacingError("Сначала зайдите в голосовой канал");
+      if (options.voiceChannelId && options.voiceChannelId !== listening.id) {
+        throw new UserFacingError("Бота можно позвать только в тот канал, где вы находитесь");
+      }
+    }
+
+    const target = config.REQUIRE_LISTENER
+      ? listening
+      : (options.voiceChannelId
+          ? this.chat.getVoiceChannel(options.voiceChannelId)
+          : (listening ?? (player.voiceChannelId ? this.chat.getVoiceChannel(player.voiceChannelId) : null)));
 
     if (!target) {
       throw new UserFacingError("Зайдите в голосовой канал или укажите его явно");