feat: facturación primer pago, fixes SAT/MP, autocompletado RFCs/conceptos

Backend:
- Notificación email al admin cuando llega primer pago aprobado (sin factura auto)
- Endpoints GET /pagos-sin-factura y POST /emitir-factura-pago para admin global
- Fix vinculación org Facturapi Horux 360 (69f23a5a242e0af47a41fa0d)
- Fix webhook MP: validación defensiva de x-signature header
- Fix autocompleto RFCs: eliminado filtro por contribuyenteId
- Fix autocompleto conceptos: eliminado filtro por contribuyenteId
- SAT fixes: anti-bot CSF scraper, request reuse, date range fix, stale job thresholds
- SAT sync request reuse across jobs para evitar agotar cuota diaria
- Typo fix MP_ACCESS_TOKEN en .env
- Trial invitations system backend

Frontend:
- Nueva página /admin/facturas-pendientes con tabla y emisión manual
- Métrica 'Facturas pendientes' en /clientes (clickable)
- Navegación onboarding FIEL/CSD corregida
- Sidebar themes sincronizados
- Fix SAT portal migration scraper (NetIQ)
- Trial invitation acceptance pages

apps/web/lib/api/trial-invitations.ts

@@ -0,0 +1,70 @@
+import { apiClient } from './client';
+
+export interface TrialInvitation {
+  id: string;
+  tenantId: string;
+  plan: string;
+  durationDays: number;
+  status: string;
+  token: string;
+  sentAt: string;
+  expiresAt: string;
+  acceptedAt: string | null;
+  tenant: {
+    nombre: string;
+    rfc: string;
+  } | null;
+}
+
+export async function getPendingInvitation(): Promise<TrialInvitation | null> {
+  try {
+    const response = await apiClient.get<TrialInvitation | null>('/invitations/trial/pending');
+    return response.data;
+  } catch (error: any) {
+    if (error?.response?.status === 404) return null;
+    throw error;
+  }
+}
+
+export async function getInvitationByToken(token: string): Promise<TrialInvitation | null> {
+  try {
+    const response = await apiClient.get<TrialInvitation | null>(`/invitations/trial/token/${token}`);
+    return response.data;
+  } catch (error: any) {
+    if (error?.response?.status === 404) return null;
+    throw error;
+  }
+}
+
+export async function acceptInvitation(token: string): Promise<{
+  success: boolean;
+  trialEndsAt: string;
+  plan: string;
+  durationDays: number;
+}> {
+  const response = await apiClient.post(`/invitations/trial/${token}/accept`);
+  return response.data;
+}
+
+// Admin endpoints
+export async function getAllInvitations(filters?: { tenantId?: string; status?: string }): Promise<TrialInvitation[]> {
+  const params = new URLSearchParams();
+  if (filters?.tenantId) params.append('tenantId', filters.tenantId);
+  if (filters?.status) params.append('status', filters.status);
+  const response = await apiClient.get<TrialInvitation[]>(`/invitations/trial?${params.toString()}`);
+  return response.data;
+}
+
+export async function createInvitation(data: {
+  tenantId: string;
+  plan?: string;
+  durationDays: number;
+}): Promise<TrialInvitation> {
+  const response = await apiClient.post<TrialInvitation>('/invitations/trial', data);
+  return response.data;
+}
+
+export async function cancelInvitation(id: string): Promise<TrialInvitation> {
+  const response = await apiClient.post<TrialInvitation>(`/invitations/trial/${id}/cancel`);
+  return response.data;
+}