feat: Funcion de sistema tenants

backend/app/models/system.py

@@ -4,11 +4,10 @@ Sistemas afectados por tenant
 """
 from sqlalchemy import String, Text, Boolean, ForeignKey, UniqueConstraint
 from sqlalchemy.orm import Mapped, mapped_column, relationship
-from sqlalchemy.dialects.postgresql import UUID
 from typing import List, Optional
 import uuid
 
-from app.core.database import Base
+from app.core.database import Base, GUID
 
 class System(Base):
     """Modelo de sistemas afectados (affected_systems en BD)"""
@@ -21,7 +20,7 @@ class System(Base):
     
     # ✅ AÑADIDO: tenant_id obligatorio para multi-tenancy (faltaba completamente)
     tenant_id: Mapped[uuid.UUID] = mapped_column(
-        UUID(as_uuid=True), 
+        GUID(),
         ForeignKey("tenants.id", ondelete="CASCADE"), 
         nullable=False
     )