orbstack: Add hooks and more complete uninstall/zap (#143807)

* orbstack: Add hooks and more complete uninstall/zap

- Add postflight hook to complete update as discussed in #143806. Does nothing on first install.
- Add uninstall and zap hooks for VM cleanup (does nothing in v0.5.0 and v0.5.1, but already implemented for future versions)
- Clean up GUI app state in ~/Library on zap. (`macvirt` is the project's codename)

* orbstack: Remove ~/OrbStack mount if empty

When OrbStack is running, Docker volumes and Linux files are mounted at ~/OrbStack.

If it's not empty, users may have accidentally stored data there while it wasn't mounted, so leave it alone

* orbstack: Remove zap script

Doesn't work because it runs after uninstall. The uninstall script is enough.

Casks/orbstack.rb

@@ -21,5 +21,29 @@ cask "orbstack" do
 
   app "OrbStack.app"
 
-  zap trash: "~/.orbstack"
+  postflight do
+    system_command "#{appdir}/OrbStack.app/Contents/MacOS/bin/orbctl",
+                   args: ["_internal", "brew-postflight"]
+  end
+
+  uninstall script: {
+    executable: "#{appdir}/OrbStack.app/Contents/MacOS/bin/orbctl",
+    args:       ["_internal", "brew-uninstall"],
+  }
+
+  zap trash: [
+        "~/.orbstack",
+        "~/Library/Caches/dev.kdrag0n.MacVirt",
+        "~/Library/HTTPStorages/dev.kdrag0n.MacVirt",
+        "~/Library/Preferences/dev.krag0n.MacVirt.plist",
+        "~/Library/WebKit/dev.kdrag0n.MacVirt",
+        "~/Library/Saved Application State/dev.kdrag0n.MacVirt.savedState",
+      ],
+      rmdir: [
+        "~/OrbStack",
+      ]
+
+  caveats <<~EOS
+    Open the OrbStack app to finish setup.
+  EOS
 end