Stabilizza live YouTube/RTMP e fix crash rotazione mobile.

Pipeline YouTube con relay, overlay e publisher sync lato backend; fix GL pauseGlDuringRotation su Android per evitare crash in rotazione durante lo streaming Flutter.

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile/lib/platform/streaming_preview.dart

@@ -2,7 +2,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-/// Preview camera nativa (OpenGL) o placeholder su altre piattaforme.
+/// Preview camera nativa (OpenGL) integrata nel layout Flutter.
 class NativeStreamingPreview extends StatelessWidget {
   const NativeStreamingPreview({
     super.key,
@@ -23,7 +23,7 @@ class NativeStreamingPreview extends StatelessWidget {
             key: key,
             viewType: 'match_live_tv/streaming_preview',
             layoutDirection: TextDirection.ltr,
-            creationParamsCodec: StandardMessageCodec(),
+            creationParamsCodec: const StandardMessageCodec(),
           ),
           if (showGrid) CameraPreviewOverlay(platformLabel: platformLabel),
         ],