Implementacion modal ticket 1

backend/app/models/ticket.py

@@ -157,5 +157,37 @@ class Ticket(Base):
         CheckConstraint('rating >= 1 AND rating <= 5', name='check_rating_range'),
     )
 
+    participants: Mapped[list["TicketParticipant"]] = relationship(
+        "TicketParticipant",
+        back_populates="ticket",
+        cascade="all, delete-orphan"
+    )
+
     def __repr__(self) -> str:
-        return f"<Ticket(id={self.id}, number='{self.ticket_number}', status={self.status})>"
+        return f"<Ticket(id={self.id}, number='{self.ticket_number}', status={self.status})>"
+
+class TicketParticipant(Base):
+    """Participantes asignados a un ticket"""
+    __tablename__ = "ticket_participants"
+
+    ticket_id: Mapped[uuid.UUID] = mapped_column(
+        GUID(),
+        ForeignKey("tickets.id", ondelete="CASCADE"),
+        nullable=False
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        GUID(),
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False
+    )
+    role: Mapped[str] = mapped_column(String(50), nullable=False, default="participant")
+
+    ticket: Mapped["Ticket"] = relationship("Ticket", back_populates="participants")
+    user: Mapped["User"] = relationship("User")
+
+    __table_args__ = (
+        UniqueConstraint("ticket_id", "user_id", name="uq_ticket_participant"),
+    )
+
+    def __repr__(self):
+        return f"<TicketParticipant(ticket={self.ticket_id}, user={self.user_id})>"