Fix WebCamTexture orientation on the wire (#276)

* Fix WebCamTexture orientation on the wire

Two related issues caused remote participants to see local video at
wrong orientations:

1. GetVideoRotation was mismapping cases: 0→_180, 180→_0, 270→_180.
   Android front cam in portrait reports videoRotationAngle == 270, so
   remotes saw the stream 90° off. Replaced with a straight passthrough
   across all four angles.

2. GetPixels32 returns rows bottom-up but WebRTC expects top-down, so
   the buffer was being sent vertically flipped. The previous "0→_180"
   mapping was masking this on desktop (180° rotation visually
   approximates a Y-flip on roughly-symmetric subjects), but it was
   never actually correct. Flip rows during the buffer copy.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

* Adds missing meta file

---------

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

Author: MaxHeimbrock

Runtime/Scripts/Internal/TaskYieldInstruction.cs.meta

@@ -28,10 +28,12 @@ protected override VideoRotation GetVideoRotation()
         {
             switch (CamTexture.videoRotationAngle)
             {
+                case 0: return VideoRotation._0;
                 case 90: return VideoRotation._90;
-                case 180: return VideoRotation._0;
+                case 180: return VideoRotation._180;
+                case 270: return VideoRotation._270;
             }
-            return VideoRotation._180;
+            return VideoRotation._0;
         }
 
         public WebCameraSource(WebCamTexture texture, VideoBufferType bufferType = VideoBufferType.Rgba) : base(VideoStreamSource.Texture, bufferType)
@@ -81,8 +83,13 @@ protected override bool ReadBuffer()
             }
 
             CamTexture.GetPixels32(_readBuffer);
-            MemoryMarshal.Cast<Color32, byte>(_readBuffer)
-                .CopyTo(_captureBuffer.AsSpan());
+            // GetPixels32 returns rows bottom-up; WebRTC expects top-down. Flip while copying.
+            var src = MemoryMarshal.Cast<Color32, byte>(_readBuffer);
+            var dst = _captureBuffer.AsSpan();
+            int rowBytes = width * GetStrideForBuffer(_bufferType);
+            for (int y = 0; y < height; y++)
+                src.Slice(y * rowBytes, rowBytes)
+                   .CopyTo(dst.Slice((height - 1 - y) * rowBytes, rowBytes));
 
             _requestPending = true;