Fix WebRTC desktop video stream rendering and inputs

lib/features/desktop/desktop_client.dart

@@ -111,14 +111,21 @@ class DesktopClient {
         }
       };
 
-      // Add transceiver for receiving video (required for unified-plan)
+      // Add transceivers for receiving video and audio
+      await _peerConnection!.addTransceiver(
+        kind: RTCRtpMediaType.RTCRtpMediaTypeAudio,
+        init: RTCRtpTransceiverInit(direction: TransceiverDirection.RecvOnly),
+      );
       await _peerConnection!.addTransceiver(
         kind: RTCRtpMediaType.RTCRtpMediaTypeVideo,
         init: RTCRtpTransceiverInit(direction: TransceiverDirection.RecvOnly),
       );
 
       // Create SDP Offer
-      final offer = await _peerConnection!.createOffer({});
+      final offer = await _peerConnection!.createOffer({
+        'offerToReceiveAudio': 1,
+        'offerToReceiveVideo': 1,
+      });
       await _peerConnection!.setLocalDescription(offer);
 
       // Send SDP Offer to Bridge

lib/features/desktop/desktop_input_handler.dart

@@ -162,10 +162,34 @@ Offset? desktopContentPosition(
 }) {
   if (viewportSize.width <= 0 || viewportSize.height <= 0) return null;
 
-  // We are using FittedBox(fit: BoxFit.fill) which stretches the video
-  // to fill the viewport exactly, without any padding/offsets.
+  if (contentSize == null || contentSize.width <= 0 || contentSize.height <= 0) {
+    return Offset(
+      (localPosition.dx / viewportSize.width).clamp(0.0, 1.0),
+      (localPosition.dy / viewportSize.height).clamp(0.0, 1.0),
+    );
+  }
+
+  final double viewportRatio = viewportSize.width / viewportSize.height;
+  final double contentRatio = contentSize.width / contentSize.height;
+
+  double renderedWidth;
+  double renderedHeight;
+
+  if (viewportRatio > contentRatio) {
+    // Viewport is wider, so height is the constraint
+    renderedHeight = viewportSize.height;
+    renderedWidth = renderedHeight * contentRatio;
+  } else {
+    // Viewport is taller, so width is the constraint
+    renderedWidth = viewportSize.width;
+    renderedHeight = renderedWidth / contentRatio;
+  }
+
+  final double dxOffset = (viewportSize.width - renderedWidth) / 2;
+  final double dyOffset = (viewportSize.height - renderedHeight) / 2;
+
   return Offset(
-    (localPosition.dx / viewportSize.width).clamp(0.0, 1.0),
-    (localPosition.dy / viewportSize.height).clamp(0.0, 1.0),
+    ((localPosition.dx - dxOffset) / renderedWidth).clamp(0.0, 1.0),
+    ((localPosition.dy - dyOffset) / renderedHeight).clamp(0.0, 1.0),
   );
 }

lib/features/desktop/desktop_view.dart

@@ -102,6 +102,11 @@ class _DesktopViewState extends State<DesktopView> {
 
   Future<void> _initRenderer() async {
     await _localRenderer.initialize();
+    _localRenderer.onResize = () {
+      if (mounted) {
+        setState(() {});
+      }
+    };
   }
 
   @override