Adding initial playback bar logic.

Harmonia.UI/App.axaml

@@ -1,12 +1,15 @@
 <Application xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 			 xmlns:vm="clr-namespace:Harmonia.UI.ViewModels"
+			 xmlns:control="clr-namespace:Harmonia.UI.Controls"
+			 xmlns:semi="https://irihi.tech/semi"
              x:Class="Harmonia.UI.App"
              RequestedThemeVariant="Default">
              <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
 
     <Application.Styles>
-        <FluentTheme />
+        <!--<FluentTheme />-->
+		<semi:SemiTheme Locale="en-US"/>
     </Application.Styles>
 
 	<Application.Resources>