--extension calls connectOverCDP without noDefaults, unlike --cdp-endpoint after #41676. This overrides the existing browser context, including forcing prefers-color-scheme: light.
createExtensionBrowser should pass noDefaults: true, as supported by #40185.
--extensioncallsconnectOverCDPwithoutnoDefaults, unlike--cdp-endpointafter #41676. This overrides the existing browser context, including forcingprefers-color-scheme: light.createExtensionBrowsershould passnoDefaults: true, as supported by #40185.