security: harden data auth and deployment

frontend/app/admin/invites/page.tsx

@@ -36,6 +36,7 @@ type Profile = {
 type Invite = {
   id: number
   code: string
+  code_available?: boolean
   label?: string | null
   description?: string | null
   profile_id?: number | null
@@ -501,17 +502,30 @@ export default function AdminInviteManagementPage() {
   }
 
   const copyInviteLink = async (invite: Invite) => {
-    const url = `${signupBaseUrl}?code=${encodeURIComponent(invite.code)}`
     try {
+      let usableInvite = invite
+      if (!invite.code_available) {
+        const response = await authFetch(`${getApiBase()}/admin/invites/${invite.id}/rotate`, {
+          method: 'POST',
+        })
+        if (!response.ok) {
+          if (handleAuthResponse(response)) return
+          throw new Error((await response.text()) || 'Could not generate a replacement link.')
+        }
+        const data = await response.json()
+        usableInvite = data.invite as Invite
+        setInvites((current) => current.map((item) => item.id === invite.id ? usableInvite : item))
+      }
+      const url = `${signupBaseUrl}?code=${encodeURIComponent(usableInvite.code)}`
       if (navigator.clipboard?.writeText) {
         await navigator.clipboard.writeText(url)
-        setStatus(`Copied invite link for ${invite.code}.`)
+        setStatus(`Copied the invite link. Keep it safe; Magent will not display it again after this page reloads.`)
       } else {
         window.prompt('Copy invite link', url)
       }
     } catch (err) {
       console.error(err)
-      window.prompt('Copy invite link', url)
+      setError(err instanceof Error ? err.message : 'Could not generate or copy the invite link.')
     }
   }
 
@@ -1666,7 +1680,7 @@ export default function AdminInviteManagementPage() {
                     </div>
                     <div className="admin-inline-actions">
                       <button type="button" className="ghost-button" onClick={() => copyInviteLink(invite)}>
-                        Copy link
+                        {invite.code_available ? 'Copy link' : 'Generate replacement link'}
                       </button>
                       <button
                         type="button"