Monitor session context levels and proactively save checkpoints before compaction. Use when: (1) session context exceeds 80% capacity, (2) user asks about session status or memory, (3) at the start of each new session to check context, or (4) before long tasks that might push context over threshold.

监控会话上下文层级，并在压缩前主动保存检查点。适用场景：（1）会话上下文容量超过80%；（2）用户询问会话状态或内存情况；（3）每个新会话开始时检查上下文；（4）执行可能使上下文超出阈值的长时间任务前。