Custom Header support for iOS app

[FinleyJDev]

Is your feature request related to a problem? Please describe.
My evcc is secured behind a cloudflared tunnel and then exposed to the internet. I can't access it from the iOS app because it doesn't support the authentication via safari.

Describe the solution you'd like
The easiest way would be to add an option in the app where you can configure custom headers that are sent with every request made. This way you could add Cloudflare service auth tokens.

Describe alternatives you've considered
I've considerd trying to use the cookies one gets from authenticating in the browser from cloudflare but that doesn't work or i don't have the technical know how.

[naltatis]

See also #35

[naltatis]

Just came across the immich app. They're doing exactly this to support cloud flare tunneling.
immich-app/immich#10588

Guess this would be a pretty straightforward option which also has the benefit of working stateless (no intermediate login flow and cookies we have to take care of). Would also work for widget use-cases.

Screenshot from the immich iOS app