Random colours!

[GustavPersson]

Allow each project to have a color, which is used to derive activity
colors. The first activity inherits the project color, and subsequent
activities progressively darken it by 10%.

The frontend provides a color picker with a curated palette of 16
visually distinct default colors. The backend API accepts color as an
optional field for backwards compatibility — existing projects without
a color fall back to #457b9d.

[eliasson]

@GustavPersson I completely missed that I received this PR.

I like the idea of using gradient colours for a project, at least that you get the colour suggested and can override. There's a few merge conflicts that needs to be handled.

Also, is this Claude's work?

[GustavPersson]

@GustavPersson I completely missed that I received this PR.

I like the idea of using gradient colours for a project, at least that you get the colour suggested and can override. There's a few merge conflicts that needs to be handled.

Also, is this Claude's work?

I just kept forgetting to change my colours and got the same one for all projects, so this is what resulted!

I'll look at the conflicts!

The work is claude-assisted, it's not completely AI but I didn't want to read a lot of documentation

[eliasson]

@GustavPersson I completely missed that I received this PR.
I like the idea of using gradient colours for a project, at least that you get the colour suggested and can override. There's a few merge conflicts that needs to be handled.

I just kept forgetting to change my colours and got the same one for all projects, so this is what resulted!

I'll look at the conflicts!

Great! Try to make slightly smaller and more frequent commits (that makes it easier to review).

Also, please add some screenshots on how the updated UI looks.

I do not mind AI assisted work (on this project at least, as long as you cannot tell the difference between a man- and machine-made change). Maybe I should add a CLAUDE.md file in the repository 🤔