Widgets dont receive a theme if the settings are set to "system"

[MTRNord]

Steps to reproduce

1. Use the system theme in element-web
2. Have a widget defining $org.matrix.msc2873.client_theme in their URL

Outcome

What did you expect?

It translates "system" to either "dark" or "light"

What happened instead?

It omits the theme entirely and causes a default to light therefor

Operating system

Fedora Silverblue 40

Browser information

Firefox 129.0 (64-Bit)

URL for webapp

develop.element.io

Application version

Version von Element: 43fa2e533f79-react-9f5b39b9d951-js-d6080398dbf5 Krypto-Version: Rust SDK 0.7.1 (c8c9d15), Vodozemac 0.6.0

Homeserver

matrix.midnightthoughts.space

Will you send logs?

No

[MTRNord]

This is most likely because with system set SettingsStore.getValue("theme") returns undefined when passed to the theme url generator function

[t3chguy]

The widget could be expected to query the browser prefs itself in this case