空闲会话自动压缩省用量

要点

1. Claude Code 会在提示缓存过期前（约 1 小时）自动压缩空闲过久的长会话。
2. 回来后续聊时只需重处理摘要，不必重跑整段对话，从而节省用量。
3. 适合长时间挂着、中途离开再回来的大会话。

原帖开头

We recently added idle compaction to Claude Code! It now compacts long idle sessions right before the prompt cache expires (~1h). If you come back to it later, it only has to reprocess the summary instead of the entire conversation, which saves you some usage.