v2.0.0 — Astro 7 support

Astro 7 support

This release adds support for Astro 7 and drops Astro 5.

Changes

• peerDependencies.astro: ^5 || ^6 → ^6 || ^7
• Dev/build against Astro 7 + Vite 8
• engines.node raised to >=22.12.0 (matches Astro 7's floor)
• CI publish workflow runs on Node 22

Breaking

• Astro 5 is no longer supported. Upgrade to Astro 6 or 7.
• Node 18/20 below 22.12.0 are no longer supported.

Verified

Package build + 39 unit tests pass; SSG, SSR, and Server-Islands (server:defer) sample apps build cleanly on Astro 7.0.3 / Vite 8.1.0.