Refactor settings management in PLib video library manager. Replace dialog-based settings with a single-panel overlay for improved user experience. Update MainWindow and SettingsView to support new settings panel, and adjust ViewModels accordingly. Enhance README.md to reflect these changes.

src/PLib.Desktop/Views/MainWindow.axaml

@@ -2,6 +2,7 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:controls="clr-namespace:PLib.Desktop.Controls"
         xmlns:icons="clr-namespace:Material.Icons.Avalonia;assembly=Material.Icons.Avalonia"
+        xmlns:views="clr-namespace:PLib.Desktop.Views"
         xmlns:vm="clr-namespace:PLib.Desktop.ViewModels"
         x:Class="PLib.Desktop.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
@@ -15,6 +16,10 @@
 
   <Window.Resources>
 
+    <DataTemplate x:Key="SettingsTemplate" DataType="vm:SettingsViewModel">
+      <views:SettingsView />
+    </DataTemplate>
+
     <!-- ======================= Video card ======================= -->
     <DataTemplate x:Key="VideoCardTemplate" DataType="vm:VideoCardViewModel">
       <Button Classes="card" Command="{Binding PlayCommand}" ToolTip.Tip="{Binding FullPath}">
@@ -234,5 +239,17 @@
       </Grid>
     </Border>
 
+    <!-- ======================= Settings panel ======================= -->
+    <Panel Grid.Row="0"
+           Grid.RowSpan="3"
+           Classes="settingsOverlay"
+           Classes.open="{Binding IsSettingsOpen}">
+      <Button Classes="scrim" Command="{Binding CloseSettingsCommand}" />
+      <Border Classes="drawer">
+        <ContentControl Content="{Binding SettingsPanel}"
+                        ContentTemplate="{StaticResource SettingsTemplate}" />
+      </Border>
+    </Panel>
+
   </Grid>
 </Window>