feat(docs): preserve all live URLs at cutover (redirects + CNAME)

The old Docusaurus site served docs under /docs/... (guide pages flattened
via slug overrides). Add an Astro `redirects` map covering all 64 live
echo.labstack.com URLs -> their new locations, so nothing 404s after cutover
and SEO/backlinks survive. Astro emits a static meta-refresh page per entry,
which works on GitHub Pages (no _redirects file needed).

Also add site/public/CNAME so the custom domain survives when the deploy
target switches from website/ to site/ at cutover.

Verified: 64/64 live sitemap URLs resolve in the build (page or redirect).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: vishr

site/astro.config.mjs

@@ -4,6 +4,74 @@ import starlight from '@astrojs/starlight';
 // https://astro.build/config
 export default defineConfig({
   site: 'https://echo.labstack.com',
+  // Preserve every live Docusaurus URL at cutover. The old site served docs under
+  // /docs/... (flattened guide pages via slug overrides); Astro generates a static
+  // meta-refresh page per entry (works on GitHub Pages — no _redirects needed).
+  redirects: {
+    '/docs': '/guide/quickstart/',
+    '/docs/binding': '/guide/binding/',
+    '/docs/category/cookbook': '/cookbook/hello-world/',
+    '/docs/category/guide': '/guide/quickstart/',
+    '/docs/category/middleware': '/middleware/basic-auth/',
+    '/docs/cookbook/auto-tls': '/cookbook/auto-tls/',
+    '/docs/cookbook/cors': '/cookbook/cors/',
+    '/docs/cookbook/crud': '/cookbook/crud/',
+    '/docs/cookbook/embed-resources': '/cookbook/embed-resources/',
+    '/docs/cookbook/file-download': '/cookbook/file-download/',
+    '/docs/cookbook/file-upload': '/cookbook/file-upload/',
+    '/docs/cookbook/graceful-shutdown': '/cookbook/graceful-shutdown/',
+    '/docs/cookbook/hello-world': '/cookbook/hello-world/',
+    '/docs/cookbook/http2': '/cookbook/http2/',
+    '/docs/cookbook/http2-server-push': '/cookbook/http2-server-push/',
+    '/docs/cookbook/jsonp': '/cookbook/jsonp/',
+    '/docs/cookbook/jwt': '/cookbook/jwt/',
+    '/docs/cookbook/load-balancing': '/cookbook/load-balancing/',
+    '/docs/cookbook/middleware': '/cookbook/middleware/',
+    '/docs/cookbook/reverse-proxy': '/cookbook/reverse-proxy/',
+    '/docs/cookbook/sse': '/cookbook/sse/',
+    '/docs/cookbook/streaming-response': '/cookbook/streaming-response/',
+    '/docs/cookbook/subdomain': '/cookbook/subdomain/',
+    '/docs/cookbook/timeout': '/cookbook/timeout/',
+    '/docs/cookbook/websocket': '/cookbook/websocket/',
+    '/docs/cookies': '/guide/cookies/',
+    '/docs/customization': '/guide/customization/',
+    '/docs/error-handling': '/guide/error-handling/',
+    '/docs/ip-address': '/guide/ip-address/',
+    '/docs/middleware/basic-auth': '/middleware/basic-auth/',
+    '/docs/middleware/body-dump': '/middleware/body-dump/',
+    '/docs/middleware/body-limit': '/middleware/body-limit/',
+    '/docs/middleware/casbin-auth': '/middleware/casbin-auth/',
+    '/docs/middleware/context-timeout': '/middleware/context-timeout/',
+    '/docs/middleware/cors': '/middleware/cors/',
+    '/docs/middleware/csrf': '/middleware/csrf/',
+    '/docs/middleware/decompress': '/middleware/decompress/',
+    '/docs/middleware/gzip': '/middleware/gzip/',
+    '/docs/middleware/jwt': '/middleware/jwt/',
+    '/docs/middleware/key-auth': '/middleware/key-auth/',
+    '/docs/middleware/logger': '/middleware/logger/',
+    '/docs/middleware/method-override': '/middleware/method-override/',
+    '/docs/middleware/open-telemetry': '/middleware/open-telemetry/',
+    '/docs/middleware/prometheus': '/middleware/prometheus/',
+    '/docs/middleware/proxy': '/middleware/proxy/',
+    '/docs/middleware/rate-limiter': '/middleware/rate-limiter/',
+    '/docs/middleware/recover': '/middleware/recover/',
+    '/docs/middleware/redirect': '/middleware/redirect/',
+    '/docs/middleware/request-id': '/middleware/request-id/',
+    '/docs/middleware/rewrite': '/middleware/rewrite/',
+    '/docs/middleware/secure': '/middleware/secure/',
+    '/docs/middleware/session': '/middleware/session/',
+    '/docs/middleware/static': '/middleware/static/',
+    '/docs/middleware/trailing-slash': '/middleware/trailing-slash/',
+    '/docs/quick-start': '/guide/quickstart/',
+    '/docs/request': '/guide/request/',
+    '/docs/response': '/guide/response/',
+    '/docs/routing': '/guide/routing/',
+    '/docs/start-server': '/guide/customization/',
+    '/docs/static-files': '/guide/static-files/',
+    '/docs/templates': '/guide/templates/',
+    '/docs/testing': '/guide/testing/',
+    '/search': '/',
+  },
   integrations: [
     starlight({
       title: 'Echo',

site/public/CNAME

@@ -0,0 +1 @@
+echo.labstack.com