feat: 增加操作审计与受控下载

backend/models.py

@@ -60,3 +60,22 @@ class User(Base):
     password_hash = Column(String, nullable=False)
     is_admin = Column(Boolean, default=False)
     created_at = Column(TIMESTAMP, default=datetime.utcnow)
+
+
+class OperationLog(Base):
+    """用户关键操作的审计与统计记录。"""
+    __tablename__ = "operation_logs"
+
+    id = Column(String, primary_key=True)
+    created_at = Column(TIMESTAMP, default=datetime.utcnow, nullable=False)
+    username = Column(String, nullable=False)
+    is_admin = Column(Boolean, default=False, nullable=False)
+    action = Column(String, nullable=False)
+    task_id = Column(String)
+    app_id = Column(String)
+    app_name = Column(String)
+    resource_type = Column(String)
+    resource_name = Column(String)
+    detail_json = Column(Text)
+    client_ip = Column(String)
+    user_agent = Column(String)