fix(docs): disable Astro dev toolbar to suppress aria-query audit error

Known Astro 6.x bug with aria-query roles destructuring in the dev
toolbar audit. Does not affect production builds.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: iammukeshm

docs/astro.config.mjs

@@ -5,6 +5,9 @@ import sitemap from '@astrojs/sitemap';
 import mdx from '@astrojs/mdx';
 
 export default defineConfig({
+  devToolbar: {
+    enabled: false,
+  },
   site: 'https://fullstackhero.net',
   adapter: cloudflare({
     imageService: 'compile',