Run the digital bridge on Windows

The bridge launched its helper only through Wine. It now starts any
process, so on Windows it runs the helper directly. WineBridgeChannel is
renamed ProcessBridgeChannel.

WindowsControlSetup sets up the control side on Windows. The digital
dialog, AppSession, README and docs/digital-bridge.md describe the
Windows setup. publish-windows.sh builds a Windows release.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Nonemm.App/AppSession.cs

@@ -699,10 +699,12 @@ public sealed class AppSession : IDisposable
             OnTop = Settings.DigitalEngineOnTop,
             PttPort = Settings.DigitalPttPort.Trim().Length > 0 ? Settings.DigitalPttPort : null,
         };
-        WineBridgeChannel channel = new(
+        ProcessBridgeChannel channel = new(
             Settings.DigitalBridgePath,
             Settings.DigitalWinePrefix.Trim().Length > 0 ? Settings.DigitalWinePrefix : null,
-            Settings.DigitalWineCommand.Trim().Length > 0 ? Settings.DigitalWineCommand : "wine",
+            OperatingSystem.IsWindows()
+                ? null
+                : Settings.DigitalWineCommand.Trim().Length > 0 ? Settings.DigitalWineCommand : "wine",
             Paths.Diagnostics);
         MmttyEngine started = new(channel, options);
         await started.StartAsync();