refactor: strip AppShell+Sidebar wrappers from all page components

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

src/pages/Admin/Admin.tsx

@@ -1,9 +1,6 @@
 import { useNavigate, useLocation } from 'react-router-dom'
-import { AppShell } from '../../design-system/layout/AppShell/AppShell'
-import { Sidebar } from '../../design-system/layout/Sidebar/Sidebar'
 import { TopBar } from '../../design-system/layout/TopBar/TopBar'
 import { Tabs } from '../../design-system/composites/Tabs/Tabs'
-import { SIDEBAR_APPS } from '../../mocks/sidebar'
 import styles from './Admin.module.css'
 import type { ReactNode } from 'react'
 
@@ -23,7 +20,7 @@ export function AdminLayout({ title, children }: AdminLayoutProps) {
   const location = useLocation()
 
   return (
-    <AppShell sidebar={<Sidebar apps={SIDEBAR_APPS} />}>
+    <>
       <TopBar
         breadcrumb={[
           { label: 'Admin', href: '/admin' },
@@ -40,6 +37,6 @@ export function AdminLayout({ title, children }: AdminLayoutProps) {
       <div className={styles.adminContent}>
         {children}
       </div>
-    </AppShell>
+    </>
   )
 }