诚实性修复: API限流Retry-After(wait=60s)+断言 / purge定时接线(04:00 cron+actor+测试) / Channel表单校验(ref+rules+validate) / README PG数字513

backend/apps/core/tasks.py

@@ -0,0 +1,26 @@
+"""审计日志保留定时任务（P1-3 · Dramatiq actor，cron 每日调用）。
+
+复用 `purge_audit_logs` management command（默认保留 180 天、分批删、
+`--yes` 防手滑），与 `apps/billing/tasks.py` / `apps/notify/tasks.py`
+同一范式：业务函数可直接单测，actor 只做薄包装。
+"""
+
+
+def purge_expired_audit_logs(days: int = 180) -> str:
+    """删除早于保留窗口的审计日志，返回 command 回执。"""
+    from django.core.management import call_command
+
+    return call_command("purge_audit_logs", days=days, yes=True)
+
+
+try:
+    import dramatiq
+
+    purge_expired_audit_logs_actor = dramatiq.actor(
+        purge_expired_audit_logs,
+        actor_name="purge_expired_audit_logs",
+        max_retries=1,
+        time_limit=600_000,
+    )
+except ImportError:  # pragma: no cover —— 未装 dramatiq 的精简环境
+    purge_expired_audit_logs_actor = None