docs: add MES upload status tracking design spec

wanshenmean

昨天 406a7dd7ed6d1215b739a80453e2bbde0f8af643

 Code/WCS/WIDESEAWCS_Client/.omc/state/idle-notif-cooldown.json

@@ -1,3 +1,3 @@
{
  "lastSentAt": "2026-04-12T15:31:49.457Z"
  "lastSentAt": "2026-04-14T08:55:27.403Z"
}