fix: repair login endpoint registration in auth router

backend/tests/test_users.py

@@ -22,7 +22,7 @@ class TestUserAuthentication:
         }
         with patch("backend.routers.auth.get_ldap_config", return_value=ldap_config):
             response = test_client.post(
-                "/auth/login",
+                "/users/login",
                 json={"username": "testuser", "password": "password123"}
             )
         assert response.status_code == status.HTTP_200_OK
@@ -46,7 +46,7 @@ class TestUserAuthentication:
              patch("backend.routers.auth.ldap3.Server"), \
              patch("backend.routers.auth.ldap3.Connection", side_effect=Exception("Invalid credentials")):
             response = test_client.post(
-                "/auth/login",
+                "/users/login",
                 json={"username": "testuser", "password": "wrongpassword"}
             )
         assert response.status_code == status.HTTP_401_UNAUTHORIZED
@@ -67,7 +67,7 @@ class TestUserAuthentication:
         test_db.commit()
 
         response = test_client.post(
-            "/auth/login",
+            "/users/login",
             json={"username": "localuser", "password": "password123"}
         )
         assert response.status_code == status.HTTP_200_OK