Feature: Add Astro 6 support to @keystatic/astro

[HoukasaurusRex]

Summary

@keystatic/astro@5.0.6 currently declares peerDependencies: { astro: "2 || 3 || 4 || 5" }, which means it does not support Astro 6.

When used with Astro 6, the Keystatic admin UI crashes with React hook errors:

TypeError: Cannot read properties of null (reading 'useState')
    at exports.useState
    at Keystatic

This appears to be caused by Astro 6 changes in how React islands are rendered/hydrated, resulting in Keystatic's React components running outside a proper React context tree.

Environment

• @keystatic/astro: 5.0.6
• @keystatic/core: 0.5.48
• astro: 6.0.4
• react: 19.2.4
• react-dom: 19.2.4

Workaround

Downgrading to Astro 5 resolves the issue since @keystatic/astro supports Astro 2-5.

Expected Behavior

@keystatic/astro should support Astro 6 and render the admin UI without React hook errors.

[Blboun3]

All is working for me, except pnpm complaining about unmet deps. Temporary fix for me was to add

"pnpm": {
    "peerDependencyRules": {
      "ignoreMissing": [],
      "allowedVersions": {
        "@keystatic/astro>astro": "6"
      }
    }
  }

into my package.json, telling pnpm to ignore that the dependencies are unmet.
At least for my use cases everything seems to be working.

@keystatic/core: 0.5.48
@keystatic/astro: 5.0.6
astro: 6.0.4
react: 19.2.4
react-dom: 19.2.4