Document desktop single-file publish

.gitignore

@@ -1,5 +1,6 @@
 bin/
 obj/
+publish/
 .vs/
 .vscode/
 *.user

README.md

@@ -18,3 +18,25 @@ dotnet run --project .\WirelessTextSyncer.Windows\WirelessTextSyncer.Windows.csp
 
 The initial server listens on `ws://0.0.0.0:8181`.
 
+## Release Build
+
+Build a Windows x64 single-file executable:
+
+```powershell
+dotnet publish .\WirelessTextSyncer.Windows\WirelessTextSyncer.Windows.csproj `
+  -c Release `
+  -r win-x64 `
+  --self-contained true `
+  -p:PublishSingleFile=true `
+  -p:EnableCompressionInSingleFile=true `
+  -p:IncludeNativeLibrariesForSelfExtract=true `
+  -o .\publish\win-x64-single
+```
+
+The runnable app is written to:
+
+```text
+publish\win-x64-single\WirelessTextSyncer.Windows.exe
+```
+
+This build includes the .NET runtime, so the target Windows machine does not need .NET installed. The generated `.pdb` file is only for debugging and is not required to run the app.