feat(backend): Update models and endpoints configuration

- Enhanced ticket and comment models with proper relationships
- Updated client_profile model for better data handling
- Improved auth endpoint with better error handling
- Updated main app configuration and imports
- Added new dependencies to requirements.txt
- Enhanced tickets endpoint with attachment support

backend/app/models/client_profile.py

@@ -8,12 +8,15 @@ Almacena información detallada de la empresa cliente
 from sqlalchemy import String, Boolean, DateTime, ForeignKey, Text, Numeric
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.dialects.postgresql import UUID
-from typing import Optional
+from typing import Optional, TYPE_CHECKING
 import uuid
 from datetime import datetime
 
 from app.core.database import Base
 
+if TYPE_CHECKING:
+    from app.models.tenant import Tenant
+
 
 class ClientProfile(Base):
     """Modelo de Perfil de Cliente Empresarial."""