docs: add release notes for v0.6.0

[uemuradevexe]

Summary

• Add release notes for v0.6.0 (docs/content/blog/2026-02-22-rapina-0-6-0.md)
• Covers route auto-discovery, Prometheus metrics, security hardening, community tooling, and the toml 1.0 bump

closes #450

[ShiraiEd]

Ci is blocking this, #477 #478 and #479 due to the outdated rapina versions

We should change the CI so that the future release notes don't face the same problem

Should we make a new issue and merge it's pr before the releases or change it right here?

[arferreira]

Yes, well I guess this can be a follow-up, to come first though! That version check greps all of docs/ for version strings, we need to exclude the blog directory from that grep. Feel free to open and tackle that if you want @ShiraiEd or @uemuradevexe.

[ShiraiEd]

LGTM

I will tackle that CI check before then

[ShiraiEd]

pr #491