Fix tilemap asset loading

src/ReactorMaintenance.Win2D/MainWindow.xaml

@@ -4,7 +4,6 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:canvas="using:Microsoft.Graphics.Canvas.UI.Xaml"
     Title="Reactor Maintenance">
-
     <Grid Background="#16191D">
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto" />

src/ReactorMaintenance.Win2D/MainWindow.xaml.cs

@@ -50,7 +50,8 @@ public sealed partial class MainWindow
 
     private async Task LoadTilemapAsync(CanvasControl sender)
     {
-        m_TerrainTilemap = await CanvasBitmap.LoadAsync(sender, new Uri("ms-appx:///Images/tilemap.png"));
+        var tilemapPath = Path.Combine(AppContext.BaseDirectory, "Images", "tilemap.png");
+        m_TerrainTilemap = await CanvasBitmap.LoadAsync(sender, tilemapPath);
     }
 
     private void ToolPicker_SelectionChanged(object sender, SelectionChangedEventArgs e)

src/ReactorMaintenance.Win2D/ReactorMaintenance.Win2D.csproj

@@ -26,6 +26,8 @@
     </ItemGroup>
 
     <ItemGroup>
-        <Content Include="Images\tilemap.png" CopyToOutputDirectory="PreserveNewest" />
+        <Content Update="Images\tilemap.png">
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+        </Content>
     </ItemGroup>
 </Project>