feat: 多用户系统改造（数据模型 + 认证 API）

backend/diary_system/settings.py

@@ -21,8 +21,10 @@ INSTALLED_APPS = [
     'django.contrib.messages',
     'django.contrib.staticfiles',
     'rest_framework',
+    'rest_framework.authtoken',
     'corsheaders',
     'diary',
+    'authentication',
 ]
 
 MIDDLEWARE = [

backend/diary_system/urls.py

@@ -6,5 +6,6 @@ from django.urls import path, include
 
 urlpatterns = [
     path('admin/', admin.site.urls),
+    path('api/auth/', include('authentication.urls')),
     path('api/', include('diary.urls')),
 ]