Add “Do not switch” rule when connected to specific Wi-Fi (SSID) or at a saved location

**Enhancement**
Please add an option to prevent Auto Dark Mode from switching themes when I’m connected to certain Wi-Fi networks or when I’m at a specific location. When I leave that Wi-Fi/location, switching should resume normally. E.g. when I'm on the way it's very useful to have auto dark mode when I'm disconnected from the power, but when I'm at home I want it to stay consistently in light mode.

**Alternatives considered**
Turning off auto switching entirely ("Force light theme"), but that only works until next time I connect the charger again. Or if that wouldn't be the case, then I would need to remember to disable this "Force light theme", which would be even more inconvenient.

No files, tests, or entry points are named. Start by locating the existing automatic theme-switching and “Force light theme” behavior, then determine how Wi-Fi SSIDs and saved locations could pause switching and resume it when conditions end. Done means users can configure these exclusions and switching resumes normally after leaving them.

Written by the indexing model from the issue text.