[Windows] Launch Fluxer at login setting is controlled by windows autostart and doesn't work in fluxer settings

blocks changing it

Canary 783 (c71cae2), Host 0.0.225, Windows 11 10.0.26200 (x64), Electron 41.2.2, Chrome 146.0.7680.188, Node 24.14.1, Locale en-US

Expected behaviour either:

1. change the setting

or

2. tell me to change it in the windows autostart settings (in which case the current implementation would also incorrectly display the current state of the windows autostart setting)