Add global admin user-view preview

frontend/app/profile/invites/page.tsx

@@ -3,6 +3,7 @@
 import { useRouter } from 'next/navigation'
 import { useEffect, useMemo, useState } from 'react'
 import { authFetch, clearToken, getApiBase, getToken } from '../../lib/auth'
+import { useUserViewPreview } from '../../lib/viewMode'
 
 type ProfileInfo = {
   username: string
@@ -97,7 +98,7 @@ export default function ProfileInvitesPage() {
   const [inviteManagedByMaster, setInviteManagedByMaster] = useState(false)
   const [masterInviteTemplate, setMasterInviteTemplate] = useState<OwnedInvitesResponse['master_invite']>(null)
   const [loading, setLoading] = useState(true)
-  const [viewAsUser, setViewAsUser] = useState(false)
+  const viewAsUser = useUserViewPreview()
 
   const signupBaseUrl = useMemo(() => {
     if (typeof window === 'undefined') return '/signup'
@@ -136,7 +137,6 @@ export default function ProfileInvitesPage() {
   }
 
   useEffect(() => {
-    setViewAsUser(new URLSearchParams(window.location.search).get('view') === 'user')
     if (!getToken()) {
       router.push('/login')
       return
@@ -309,11 +309,6 @@ export default function ProfileInvitesPage() {
 
   const canManageInvites = profile?.role === 'admin' || inviteAccessEnabled
 
-  const enterUserView = () => {
-    setViewAsUser(true)
-    router.replace('/profile/invites?view=user')
-  }
-
   if (loading) {
     return <main className="card">Loading invite tools...</main>
   }
@@ -330,16 +325,6 @@ export default function ProfileInvitesPage() {
           </p>
         </div>
         <div className="admin-inline-actions">
-          {profile?.role === 'admin' && !viewAsUser ? (
-            <button type="button" className="ghost-button" onClick={enterUserView}>
-              View as user
-            </button>
-          ) : null}
-          {profile?.role === 'admin' && viewAsUser ? (
-            <button type="button" onClick={() => router.push('/admin/invites')}>
-              Return to admin view
-            </button>
-          ) : null}
           <button type="button" className="ghost-button" onClick={() => router.push('/profile')}>
             Back to profile
           </button>