feat: native web view for plugins in the desktop app

CHANGELOG.md

@@ -29,6 +29,7 @@
 - Pasting a security key file now explains how to use it instead of failing to decode it
 - Plugins can add a panel that sits beside a host tab, like a terminal. You can open, resize and move it
 - The desktop app can link to a server that requires a client certificate (mutual TLS). It uses a PFX or P12 file for sync and the certificate in your system store for the app window
+- Plugins can show a web page in a native view in the desktop app, for sites that do not load in an iframe
 
 ### Changed