fix cuser_role model and add unique together

apps/cuser/models.py

@@ -30,6 +30,9 @@ class CuserRole(BaseModel):
     uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
     is_active = models.BooleanField(default=False)
 
+    class Meta:
+        unique_together = ('cuser', 'role_type', 'sys_ws', )
+
     def __str__(self):
         return f'{str(self.cuser) } - { str(self.id) }'