feat(global) several major updates:

- delete page `tag`, `archive`
- add page `friends`
- implement page `about` *partially*

frontend/app/friends/layout.tsx

@@ -0,0 +1,15 @@
+import React from 'react';
+
+function Layout({
+    children
+}: {
+    children: React.ReactNode;
+}) {
+    return (
+        <div className={ 'p-7' }>
+            { children }
+        </div>
+    );
+}
+
+export default Layout;