Address remaining review items (queue, selfbot v6 API, ldconfig, resample)

- voice.ts: reply playback is now a FIFO queue (AudioPlayerStatus.Idle drains
  it) so concurrent speakers no longer cut each other's replies off.
- selfbot.ts: rewritten against the REAL @dank074/discord-video-stream v6 API
  (verified from its d.ts): prepareStream(input, opts, signal)->{command,output},
  playStream(output, streamer, {type:"go-live"}, signal), Streamer.joinVoice.
  x11grab via customInputOptions; optional NVENC encode (RTX 5050) via exported
  `nvenc`. package.json pinned to ^6.0.0 (was a wrong ^4.2.1).
- Dockerfile: dropped the hardcoded python3.12 LD_LIBRARY_PATH. faster-whisper
  >=1.1 self-locates the pip CUDA libs; ldconfig (full path, glob) registers
  them as a robust fallback. Verified: ld.so cache lists libcublas/libcudnn and
  GPU whisper works with LD_LIBRARY_PATH empty.
- bridge: STT resample 48k->16k upgraded from nearest-neighbor to linear
  (np.interp).

Verified: tsc clean, image builds, GPU whisper OK via ldconfig, compose valid.

bot/src/voice.ts

@@ -15,6 +15,7 @@ import {
   createAudioResource,
   EndBehaviorType,
   StreamType,
+  AudioPlayerStatus,
   VoiceConnection,
   VoiceConnectionStatus,
   entersState,
@@ -65,6 +66,9 @@ export class VoiceSession {
   private connection: VoiceConnection;
   private player: AudioPlayer;
   private listening = new Set<string>();
+  /** Pending reply clips. Played one at a time so concurrent speakers don't
+   *  cut each other's replies off. */
+  private playQueue: Buffer[] = [];
   /** Optional callback to surface transcripts/replies to a text channel. */
   onTurn?: (info: { user: string; transcript: string; reply: string }) => void;
 
@@ -79,6 +83,8 @@ export class VoiceSession {
     });
     this.player = createAudioPlayer();
     this.connection.subscribe(this.player);
+    // Drain the queue when the current clip finishes.
+    this.player.on(AudioPlayerStatus.Idle, () => this.pump());
     this.attachReceiver();
   }
 
@@ -128,9 +134,17 @@ export class VoiceSession {
     }
   }
 
-  /** Play a WAV buffer into the channel. */
+  /** Queue a WAV buffer for playback (FIFO, one clip at a time). */
   play(wav: Buffer) {
-    const resource = createAudioResource(Readable.from(wav), {
+    this.playQueue.push(wav);
+    this.pump();
+  }
+
+  private pump() {
+    if (this.player.state.status !== AudioPlayerStatus.Idle) return;
+    const next = this.playQueue.shift();
+    if (!next) return;
+    const resource = createAudioResource(Readable.from(next), {
       inputType: StreamType.Arbitrary,
     });
     this.player.play(resource);