添加播放封面

src/Desktop/BiliCopilot.UI/Controls/Core/Player/BiliPlayer.xaml

@@ -11,7 +11,13 @@
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d">
 
-    <Grid x:Name="RootGrid" Margin="0,0,-2,-2">
+    <Grid x:Name="RootGrid" Background="Black">
+        <Image
+            HorizontalAlignment="Stretch"
+            VerticalAlignment="Stretch"
+            Source="{x:Bind ViewModel.Cover, Mode=OneWay, Converter={StaticResource BitmapConverter}}"
+            Stretch="Uniform"
+            Visibility="{x:Bind ViewModel.Cover, Mode=OneWay, Converter={StaticResource ObjectToVisibilityConverter}}" />
         <local:PlayerPresenter x:Name="PlayerPresenter" />
         <Grid x:Name="HiddenControlsContainer">
             <Button

src/Desktop/BiliCopilot.UI/ViewModels/Core/PlayerViewModelBase/PlayerViewModelBase.Properties.cs

@@ -116,6 +116,9 @@ public abstract partial class PlayerViewModelBase
     [ObservableProperty]
     private bool _isAmdMpvWarningShown;
 
+    [ObservableProperty]
+    private Uri? _cover;
+
     /// <summary>
     /// 播放数据加载完成.
     /// </summary>

src/Desktop/BiliCopilot.UI/ViewModels/Core/PlayerViewModelBase/PlayerViewModelBase.cs

@@ -38,6 +38,11 @@ public void InitializeSmtc(string cover, string title, string subtitle)
             return;
         }
 
+        if (!string.IsNullOrEmpty(cover))
+        {
+            Cover = new Uri(cover);
+        }
+
         var updater = _smtc.DisplayUpdater;
         updater.ClearAll();
         updater.Type = MediaPlaybackType.Video;