feat: add header

next.config.mjs

@@ -1,6 +1,7 @@
 import { execa } from 'execa'
 
 const commitHash = await execa('git', ['rev-parse', 'HEAD'])
+const now = new Date().toISOString()
 
 /** @type {import('next').NextConfig} */
 const nextConfig = {
@@ -13,8 +14,31 @@ const nextConfig = {
   trailingSlash: true,
   env: {
     COMMIT_HASH: commitHash.stdout,
-    BUILD_DATE: new Date().toISOString(),
+    BUILD_DATE: now,
   },
+  headers: async () => [
+    {
+      source: '/:path*',
+      headers: [
+        {
+          key: 'X-Poi-Codename',
+          value: 'Asashio',
+        },
+        {
+          key: 'X-Poi-Revision',
+          value: commitHash.stdout ?? 'development',
+        },
+        {
+          key: 'X-Poi-Build-Date',
+          value: now,
+        },
+        {
+          key: 'X-Poi-Greetings',
+          value: 'poi?',
+        },
+      ],
+    },
+  ],
 }
 
 export default nextConfig