feat: payments module, notification templates, WA float, route fixes

- Add PaymentsModule: POST /payments/intent, POST /:id/confirm, GET /payments, GET /payments/package/:id, GET /payments/track/:trackingId
- Add Payment model to Prisma schema (PaymentStatus enum, Payment table)
- Add NotificationTemplate model + NotificationsController (GET/PUT /notification-templates, POST /notification-templates/seed)
- Update NotificationsService: DB-backed templates with variable interpolation {{trackingId}} {{firstName}} {{status}} {{suiteCode}}
- Fix /bodega/paquetes: replace 11 wrong status strings with correct §08 enum values
- Fix /admin/reportes: replace EN_CAMINO_A_ECUADOR with correct §08 statuses, rewrite report page with proper KPIs and bar charts
- Fix /portal/mis-paquetes: correct §08 statuses, add 'Pagar envío' button for VERIFICADO/DECLARACION_ADUANERA packages
- Add WhatsApp float component (_components/whatsapp-float.tsx, 2 contacts: NJ ops + Cuenca aduana)
- Add /casillero/calculadora and /casillero/registro redirects (§20)
- Add /portal/pago payment page with cost breakdown (§09/§14/§15)
- Add /admin/notificaciones page: view/edit/toggle templates per event×channel
- Admin nav: add Notificaciones link
- api.ts: add notificationTemplates.* and payments.* client methods
- schema.prisma v0.4: PaymentStatus enum, Payment model, NotificationTemplate model
- db push applied to remote DB (46.202.93.92)
- All builds pass (API nest build + Next.js build)

packages/database/prisma/schema.prisma

@@ -11,6 +11,14 @@ datasource db {
   url      = env("DATABASE_URL")
 }
 
+enum PaymentStatus {
+  PENDIENTE
+  PROCESANDO
+  COMPLETADO
+  FALLIDO
+  REEMBOLSADO
+}
+
 // ─── Enums ───────────────────────────────────────────────────
 
 enum UserRole {
@@ -92,6 +100,8 @@ model Tenant {
   b2bRequests  B2BRequest[]
   warehouses   Warehouse[]
   integrations Integration[]
+  notificationTemplates NotificationTemplate[]
+  payments     Payment[]
 }
 
 // ─── Usuarios ────────────────────────────────────────────────
@@ -196,6 +206,7 @@ model Package {
   statusHistory PackageStatusHistory[]
   preAlert      PreAlert?
   notifications Notification[]
+  payment       Payment?
 
   @@index([tenantId, status])
   @@index([userId])
@@ -376,6 +387,55 @@ model Warehouse {
   @@index([tenantId])
 }
 
+// ─── Pagos (§09 paso 8 / §14 paso 5) ─────────────────────────
+
+/// Registro de pagos vinculados a un paquete.
+/// El `providerRef` es el PaymentIntent ID de Stripe (o equivalente).
+model Payment {
+  id          String        @id @default(cuid())
+  tenantId    String
+  packageId   String        @unique
+  userId      String
+  amount      Decimal       @db.Decimal(10, 2)
+  currency    String        @default("USD")
+  /// "stripe" | "payphone" | "paypal"
+  provider    String        @default("stripe")
+  /// PaymentIntent ID de Stripe u equivalente
+  providerRef String?
+  status      PaymentStatus @default(PENDIENTE)
+  paidAt      DateTime?
+  createdAt   DateTime      @default(now())
+  updatedAt   DateTime      @updatedAt
+
+  tenant  Tenant  @relation(fields: [tenantId], references: [id], onDelete: Cascade)
+  package Package @relation(fields: [packageId], references: [id], onDelete: Cascade)
+
+  @@index([tenantId, status])
+  @@index([userId])
+}
+
+// ─── Plantillas de notificación (§12) ────────────────────────
+
+/// Plantillas de mensajes para cada evento del ciclo de vida del paquete.
+/// Soporta variables: {{trackingId}}, {{firstName}}, {{status}}, {{suiteCode}}
+model NotificationTemplate {
+  id        String              @id @default(cuid())
+  tenantId  String
+  /// Evento que dispara la notificación — coincide con PackageStatus
+  event     String              // ej: "REGISTRADO", "ENTREGADO"
+  channel   NotificationChannel
+  subject   String?             // Solo relevante para EMAIL
+  body      String
+  isActive  Boolean             @default(true)
+  updatedAt DateTime            @updatedAt
+  updatedBy String?
+
+  tenant Tenant @relation(fields: [tenantId], references: [id], onDelete: Cascade)
+
+  @@unique([tenantId, event, channel])
+  @@index([tenantId, event])
+}
+
 // ─── Integraciones (API keys por tenant) ─────────────────────
 
 /// Configuración de integraciones externas (API keys, endpoints, webhooks).