docs: upgrade docs site to Astro 6 and update Node.js prerequisites (#244)

Upgrades the docs site from Astro 5/Starlight 0.37 to Astro 6/Starlight 0.38.
Adds Cloudflare adapter for deployment. Updates Node.js prerequisites
across all docs to match Astro 6's requirement of v22.12.0+.
Bumps catalog versions for @astrojs/cloudflare and wrangler.

docs/tsconfig.json

@@ -1,5 +1,5 @@
 {
 	"extends": "astro/tsconfigs/strict",
-	"include": [".astro/types.d.ts", "**/*"],
+	"include": [".astro/types.d.ts", "**/*", "./worker-configuration.d.ts"],
 	"exclude": ["dist"]
 }