feat: add admin survey invites page with create and list

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

frontend/src/api/admin.ts

@@ -20,6 +20,18 @@ import type {
   AdminUserCreateResponse,
 } from '@/types/admin'
 
+export interface SurveyInviteResponse {
+  id: string
+  token: string
+  recipient_name: string
+  recipient_email: string | null
+  status: string
+  email_sent: boolean
+  created_at: string
+  completed_at: string | null
+  survey_url: string
+}
+
 export const adminApi = {
   // Dashboard
   getDashboardMetrics: () =>
@@ -140,6 +152,12 @@ export const adminApi = {
     api.put<AdminCategory>(`/admin/categories/global/${id}`, data).then(r => r.data),
   deleteGlobalCategory: (id: string) =>
     api.delete(`/admin/categories/global/${id}`),
+
+  // Survey Invites
+  listSurveyInvites: () =>
+    api.get<SurveyInviteResponse[]>('/admin/survey-invites').then(r => r.data),
+  createSurveyInvite: (data: { recipient_name: string; recipient_email?: string; send_email?: boolean }) =>
+    api.post<SurveyInviteResponse>('/admin/survey-invites', data).then(r => r.data),
 }
 
 export default adminApi