feat: add resend capability for platform and account invite codes

Revoke-and-recreate flow for both invite systems with email delivery
via Resend API. Includes account invite email template and audit logging.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/AccountSettingsPage.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState } from 'react'
 import { Link } from 'react-router-dom'
-import { Building2, Users, Mail, Crown, Loader2, AlertCircle, Check, X, Settings, FolderTree } from 'lucide-react'
+import { Building2, Users, Mail, Crown, Loader2, AlertCircle, Check, X, Settings, FolderTree, RefreshCw } from 'lucide-react'
 import { accountsApi } from '@/api/accounts'
 import type { Account, AccountMember, AccountInvite } from '@/types'
 import { cn } from '@/lib/utils'
@@ -102,6 +102,22 @@ export function AccountSettingsPage() {
     }
   }
 
+  const [resendingId, setResendingId] = useState<string | null>(null)
+
+  const handleResendInvite = async (inviteId: string) => {
+    setResendingId(inviteId)
+    try {
+      await accountsApi.resendInvite(inviteId)
+      toast.success('Invite resent with a new code')
+      const invitesData = await accountsApi.getInvites()
+      setInvites(invitesData)
+    } catch {
+      toast.error('Failed to resend invite')
+    } finally {
+      setResendingId(null)
+    }
+  }
+
   const handleRemoveMember = async (userId: string) => {
     try {
       await accountsApi.removeMember(userId)
@@ -433,12 +449,28 @@ export function AccountSettingsPage() {
                         <div>
                           <p className="text-sm text-white">{invite.email}</p>
                           <p className="text-xs text-white/40">
-                            Expires {new Date(invite.expires_at).toLocaleDateString()}
+                            {invite.expires_at
+                              ? `Expires ${new Date(invite.expires_at).toLocaleDateString()}`
+                              : 'No expiration'}
                           </p>
                         </div>
-                        <span className="rounded-full bg-white/10 px-2.5 py-0.5 text-xs text-white/70">
-                          {invite.role}
-                        </span>
+                        <div className="flex items-center gap-2">
+                          <span className="rounded-full bg-white/10 px-2.5 py-0.5 text-xs text-white/70">
+                            {invite.role}
+                          </span>
+                          <button
+                            onClick={() => handleResendInvite(invite.id)}
+                            disabled={resendingId === invite.id}
+                            className="text-white/40 hover:text-white disabled:opacity-50"
+                            title="Resend invite"
+                          >
+                            {resendingId === invite.id ? (
+                              <Loader2 className="h-4 w-4 animate-spin" />
+                            ) : (
+                              <RefreshCw className="h-4 w-4" />
+                            )}
+                          </button>
+                        </div>
                       </div>
                     ))}
                 </div>