fix: resolve silent voice playback on VPS and queue screenshare streams

- Call unpause() when starting a stream in DiscordPlayer to prevent getting stuck in a paused state.
- Call stop() instead of pause() in VoiceController on disconnect to fully reset the player.
- Add user-agent header to ffmpeg calls in MusicPlayer and Transcoder to prevent YouTube 403 Forbidden on VPS.
- Add screenshare streams to the media queue when successfully started.

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

src/streaming/transcoder.ts

@@ -35,6 +35,16 @@ export class Transcoder {
       "-hide_banner",
       "-loglevel",
       "warning",
+    ];
+
+    if (this.source.startsWith("http://") || this.source.startsWith("https://")) {
+      args.push(
+        "-user_agent",
+        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36"
+      );
+    }
+
+    args.push(
       "-i",
       this.source,
       "-c:v",
@@ -53,8 +63,8 @@ export class Transcoder {
       "libopus",
       "-f",
       "matroska",
-      "-",
-    ];
+      "-"
+    );
 
     const cmd = spawn("ffmpeg", args, { stdio: ["ignore", "pipe", "pipe"] });
     const out = cmd.stdout ?? new PassThrough();