Implement user authentication system with custom user model, views, and templates

- Created custom User model extending Django's AbstractUser.
- Added user registration, login, and profile views with corresponding templates.
- Implemented user authentication functionality and integrated Bootstrap for styling.
- Updated project settings to use the new accounts app and user model.
- Added tests for user model and admin functionality.

accounts/tests.py

@@ -0,0 +1,66 @@
+from __future__ import annotations
+
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.urls import reverse
+
+User = get_user_model()
+
+
+class AuthenticationTestCase(TestCase):
+    """Test authentication functionality."""
+
+    def setUp(self) -> None:
+        """Set up test data."""
+        self.username = "testuser"
+        self.password = "testpass123"
+        self.user = User.objects.create_user(username=self.username, password=self.password)
+
+    def test_login_view_get(self) -> None:
+        """Test login view GET request."""
+        response = self.client.get(reverse("accounts:login"))
+        assert response.status_code == 200
+        self.assertContains(response, "Login")
+
+    def test_signup_view_get(self) -> None:
+        """Test signup view GET request."""
+        response = self.client.get(reverse("accounts:signup"))
+        assert response.status_code == 200
+        self.assertContains(response, "Sign Up")
+
+    def test_login_valid_user(self) -> None:
+        """Test login with valid credentials."""
+        response = self.client.post(reverse("accounts:login"), {"username": self.username, "password": self.password})
+        assert response.status_code == 302  # Redirect after login
+
+    def test_login_invalid_user(self) -> None:
+        """Test login with invalid credentials."""
+        response = self.client.post(reverse("accounts:login"), {"username": self.username, "password": "wrongpassword"})
+        assert response.status_code == 200  # Stay on login page
+        self.assertContains(response, "Please enter a correct username and password")
+
+    def test_profile_view_authenticated(self) -> None:
+        """Test profile view for authenticated user."""
+        self.client.login(username=self.username, password=self.password)
+        response = self.client.get(reverse("accounts:profile"))
+        assert response.status_code == 200
+        self.assertContains(response, self.username)
+
+    def test_profile_view_unauthenticated(self) -> None:
+        """Test profile view redirects unauthenticated user."""
+        response = self.client.get(reverse("accounts:profile"))
+        assert response.status_code == 302  # Redirect to login
+
+    def test_user_signup(self) -> None:
+        """Test user signup functionality."""
+        response = self.client.post(
+            reverse("accounts:signup"), {"username": "newuser", "password1": "complexpass123", "password2": "complexpass123"}
+        )
+        assert response.status_code == 302  # Redirect after signup
+        assert User.objects.filter(username="newuser").exists()
+
+    def test_logout(self) -> None:
+        """Test user logout functionality."""
+        self.client.login(username=self.username, password=self.password)
+        response = self.client.get(reverse("accounts:logout"))
+        assert response.status_code == 302  # Redirect after logout