Method load_latest_stats

backend/persistence/db.py:72–77

(self)

            )

    def load_latest_stats(self):
        with self._lock:
            row = self._conn.execute(
                "SELECT payload FROM stats_snapshots ORDER BY id DESC LIMIT 1"
            ).fetchone()
        return json.loads(row["payload"]) if row else None

    # ---- 归档与清理（控制存储增长）----
    def purge_requests_before(self, cutoff_ts):