fix(build): correct ApplicationIcon path (..\..\assets\logo.ico)

The icon path resolves relative to the project directory, so the previous
..\assets\logo.ico pointed at src\assets and broke every clean build with
CS7064 (caught by CI; local incremental build masked it).

Author: bpmcgill

src/OpenNDOF.App/OpenNDOF.App.csproj

@@ -8,7 +8,7 @@
     <UseWPF>true</UseWPF>
     <!-- Base version; CI overrides with /p:Version (tag or 1.0.0.<run#>). -->
     <Version>1.0.0</Version>
-    <ApplicationIcon>..\assets\logo.ico</ApplicationIcon>
+    <ApplicationIcon>..\..\assets\logo.ico</ApplicationIcon>
   </PropertyGroup>
 
   <ItemGroup>