enhancement: add dark theme support

[g6094199]

hi,

plz consider adding dark mode theme support in the future..

thx!

[rubenbe]

Hi!

I was going to delay it due to pocketbase But it was reasonably easy to add good-enough dark mode. So here it is 🥳

Pocketbase (the webserver used in OpenSOHO) implements it themselves now in their newest major version, so at a later stage, I'll switch to that one.
https://github.com/pocketbase/pocketbase/releases/tag/v0.37.0

It will be part of the next OpenSOHO release.

[g6094199]

oh. didnt expect that to happen so quickly.

thx, this will be eye saving ;-)