add register, login, logout views

frontend/models.py

@@ -1,3 +1,25 @@
+from django.conf import settings
 from django.db import models
+from django.db.models.signals import post_save
+from django.dispatch import receiver
 
-# Create your models here.
+
+class UserProfile(models.Model):
+    user = models.OneToOneField(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="profile",
+    )
+    display_name = models.CharField(max_length=150)
+
+    def __str__(self):
+        return f"{self.display_name} ({self.user.username})"  # type: ignore[attr-defined]
+
+
+@receiver(post_save, sender=settings.AUTH_USER_MODEL)
+def create_profile_for_user(sender, instance, created, **kwargs):
+    if created:
+        UserProfile.objects.create(  # type: ignore[attr-defined]
+            user=instance,
+            display_name=instance.username,
+        )