Add per-context color coding for Kubernetes environments

[memetics19]

Could Sofka support assigning a color to each Kubernetes context or cluster, similar to DBeaver's connection colors? For example, I would mark production red and staging yellow, with a persistent, high-contrast indicator for the active context in the header and context switcher (and ideally across resource views). This would make the current environment obvious at a glance and help prevent mistakes when switching between clusters. I've found this missing in tools like Lens and k9s. Ideally, colors would be configurable per context, with readable labels as an additional cue.

[nklmilojevic]

Thanks for the idea - knowing which cluster you're on before you delete something is a real problem!

Part of this already exists: a per-context override can set a whole skin, and readonly = true in a context override shows [read-only] in the header. Swapping the whole palette is heavy-handed though, and a skin doesn't say "prod". So yes, but in a narrower shape:

1. Per-context label - yes. A new [context_badge] table in the per-cluster or per-context override with label (f.e. "PROD") and an optional color.
2. Color - yes, as a skin color name (red, yellow, ...) so it stays readable on every skin. A color without a label is rejected with a warning - color is the extra cue, never the only one, so it works for colorblind users and monochrome terminals too.
3. Where it shows - next to the context name in the header (full and compact) and on each row of the :ctx picker, so you see prod before you switch to it.
4. Across resource views - no tinting of borders or whole views. The header is visible on every view already, and coloring the whole UI fights with row status colors.

I'll create an issue for this and link it here.

[nklmilojevic]

Created #980 for this. Closing this one, follow along there :)