Hide dock icon in no graphics mode (#653)

* Package tart binary into app bundle when running via run-signed.sh

This is what happens when installing the tart application package
as built by CI. We should stay as close as possible to the install
situation during development, so that we get bug/behavior parity.

For example, an app bundle behaves differently than a standalone
executable when it comes to bringing up a Dock icon for the app.

* Set activation policy to prohibited when starting in no graphics mode

This ensures that the Dock icon is hidden.

Sources/tart/Commands/Run.swift

@@ -312,8 +312,11 @@ struct Run: AsyncParsableCommand {
 
     let useVNCWithoutGraphics = (vnc || vncExperimental) && !graphics
     if noGraphics || useVNCWithoutGraphics {
-      // enter the main even loop and just wait for the VM to exit
-      NSApplication.shared.run()
+      // enter the main even loop, without bringing up any UI,
+      // and just wait for the VM to exit.
+      let nsApp = NSApplication.shared
+      nsApp.setActivationPolicy(.prohibited)
+      nsApp.run()
     } else {
       runUI(suspendable, captureSystemKeys)
     }

scripts/run-signed.sh

@@ -8,4 +8,8 @@ set -e
 swift build --product tart
 codesign --sign - --entitlements Resources/tart-dev.entitlements --force .build/debug/tart
 
-.build/debug/tart "$@"
+mkdir -p .build/tart.app/Contents/MacOS
+cp -c .build/debug/tart .build/tart.app/Contents/MacOS/tart
+cp -c Resources/embedded.provisionprofile .build/tart.app/Contents/embedded.provisionprofile
+
+.build/tart.app/Contents/MacOS/tart "$@"