fix(sessions): explain how to override options at runtime

[ArmandPhilippot]

Description (required)

• Updates guides/sessions to show how to override driver options at runtime.

  I took inspiration from the code snippet provided by Florian in Sessions drivers option defined at runtime roadmap#1214 (comment) with some minor changes:

  • the example was mixing .ts and .js... not sure if this was intentional
  • I guess this was written before sessionDrivers stabilization and we don't need to use unstorage directly

• Updates configuration-reference to:

  • replace the deprecated usage in "Session Options"
  • add more links to the session guide to emphasize that runtime variables may require adjustment
  • reorganize a bit the "Session Options" section

Note that I updated configuration-reference here to check and validate this is what we want, but we'll need to do the same changes in the core repo.

Related issues & labels (optional)

• Closes Clarify sessions options behavior #13028
• Suggested label: improve/update documentation

[netlify]

✅ Deploy Preview for astro-docs-2 ready!

Name	Link
🔨 Latest commit	a14b447
🔍 Latest deploy log	https://app.netlify.com/projects/astro-docs-2/deploys/69e7b16e33759e0008c7e73e
😎 Deploy Preview	https://deploy-preview-13784--astro-docs-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[astrobot-houston]

Lunaria Status Overview

🌕 This pull request will trigger status changes.

Learn more

By default, every PR changing files present in the Lunaria configuration's files property will be considered and trigger status changes accordingly.

You can change this by adding one of the keywords present in the ignoreKeywords property in your Lunaria configuration file in the PR's title (ignoring all files) or by including a tracker directive in the merged commit's description.

Tracked Files

File	Note
en/guides/sessions.mdx	Source changed, localizations will be marked as outdated.
en/reference/configuration-reference.mdx	Source changed, localizations will be marked as outdated.

Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.