style(news): put the Arendalsuka session details in callouts

[yasinmiran]

Follow-up to #314. Moves the session logistics into Callout blocks so the when and where stand out from the prose.

<Callout variant="info" title="Tuesday 11 August · 11:00-11:45 CEST">
    Bølgen 3, Arendal. Organised in collaboration with [EHiN](https://ehin.no/arendalsuka-2026/).
</Callout>

Applied to both sessions rather than only the first, since two identically shaped blocks styled differently would read as a mistake. "Session held in English" moves up into the second callout, where the rest of the practical detail lives, instead of trailing the panel list.

Callout already existed and is used this way in a 2023 article, so no component changes.

pnpm build and pnpm test:slugs pass.

[Copilot]

Pull request overview

Updates the Arendalsuka 2026 news article presentation by moving session logistics (“when/where/organiser/language”) into existing Callout components so the practical details stand out more clearly in the rendered page.

Changes:

• Adds a Callout import to the MDX article.
• Replaces the inline bold “when/where” session lines with Callout blocks for both sessions.
• Moves “Session held in English” into the second session’s callout alongside the rest of the logistics.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.