feat(common): 建立公共归属与日志基础能力

common/models.py

@@ -0,0 +1,28 @@
+"""跨业务应用复用的抽象模型。"""
+
+from django.conf import settings
+from django.db import models
+
+
+class TimeStampedModel(models.Model):
+    """统一维护创建和更新时间，避免各业务模型重复声明。"""
+
+    created_at = models.DateTimeField("创建时间", auto_now_add=True)
+    updated_at = models.DateTimeField("更新时间", auto_now=True)
+
+    class Meta:
+        abstract = True
+
+
+class UserOwnedModel(TimeStampedModel):
+    """为用户私有数据提供显式归属；审计数据存在时禁止删除用户。"""
+
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.PROTECT,
+        related_name="%(app_label)s_%(class)s_items",
+        verbose_name="所属用户",
+    )
+
+    class Meta:
+        abstract = True