task: source official OS2ai brand assets (logo, colours, fonts)

[yepzdk]

Goal

Gather the canonical OS2ai brand assets so all downstream styling uses real, official values rather than guesses. OS2ai describes itself as "En åben og fælles AI-platform" and ai-lib should present as part of it.

Background

OS2ai's exact colours and fonts are not published on the public OS2 site, so we need to source them from the OS2ai design guide / OS2 file archive ("Logoer, skabeloner, referater m.m."). This issue blocks the base-layout, colour, and typography work.

Scope

• Obtain OS2ai logo files — SVG preferred + raster fallback; light/dark variants if they exist (the public site references os2ai_Logo@2x.webp).
• Colour palette as hex: primary, secondary, neutrals, semantic (success/warning/error) where defined.
• Fonts: family name(s) + source (self-hostable web-font files or licensed CDN URL); note licence.
• Any spacing / logo clear-space / usage rules worth capturing.
• Record everything in the repo: a reference doc at docs/branding/os2ai.md plus the committed logo files (under assets/ or public/).

Acceptance criteria

• docs/branding/os2ai.md lists colours (hex), font family/families, and logo asset paths.
• OS2ai logo files committed to the repo.
• Source and licence of assets noted in the doc.

Refs https://leantime.itkdev.dk/#/tickets/showTicket/7714