Bump astro from 6.4.8 to 7.1.0 (#1557)

* Bump astro from 6.4.8 to 7.1.0

Bumps [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) from 6.4.8 to 7.1.0.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@7.1.0/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-version: 7.1.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

* build(docs): pair astro 7 with starlight 0.41 and keep unified markdown pipeline

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ryan Yang <ryan.yang@stellar.org>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: 3 people

astro.config.mjs

@@ -1,4 +1,5 @@
 import { defineConfig, fontProviders } from "astro/config";
+import { unified } from "@astrojs/markdown-remark";
 import starlight from "@astrojs/starlight";
 import sitemap from "@astrojs/sitemap";
 import GithubSlugger from "github-slugger";
@@ -87,6 +88,11 @@ export default defineConfig({
   outDir: "./dist/site",
   prefetch: { prefetchAll: true },
   markdown: {
+    // Astro 7's default Markdown processor (Sätteri) does not run unified
+    // plugins; the heading-id deference our anchor plugin relies on (see
+    // rehypeHeadingAnchors) is a markdown-remark behavior, so stay on the
+    // unified pipeline explicitly.
+    processor: unified(),
     rehypePlugins: [rehypeBaseInternalLinks, rehypeHeadingAnchors],
   },
   fonts: [

package.json

@@ -133,8 +133,9 @@
     "node": ">=22.0.0"
   },
   "devDependencies": {
+    "@astrojs/markdown-remark": "^7.2.0",
     "@astrojs/sitemap": "^3.7.3",
-    "@astrojs/starlight": "^0.40.0",
+    "@astrojs/starlight": "^0.41.3",
     "@eslint/compat": "^1.4.1",
     "@eslint/js": "^9.39.4",
     "@noble/curves": "^2.2.0",
@@ -152,7 +153,7 @@
     "@vitest/coverage-istanbul": "4.1.9",
     "@vitest/coverage-v8": "^4.1.9",
     "@vitest/ui": "^4.1.9",
-    "astro": "^6.4.8",
+    "astro": "^7.1.0",
     "browserify-zlib": "^0.2.0",
     "cross-env": "^10.1.0",
     "dotenv": "^17.4.2",