Window behavior does not meet expectation with Firefox

[realysy]

Issue: If the Open previous windows and tabs option is checked in the Firefox browser, when all Firefox windows are closed and the webui app is run, it will open as a new tab instead of a separate window using win.show(html);:

But win.show_browser(html, webui_browser::Firefox); or win.show_uv(html); can open in new window as expected, no matter system default firefox windows open or close.

My environment:

• Ubuntu 20.04
• Firefox 136.0
• webui nightly 2026-07-21
• Using example code: call_cpp_from_js/main.cpp