[iBobbyTS]

Problem

applicationWillTerminate runs its synchronous resetAuto while the monitor is still ticking and the command pump may still hold an in-flight or pending write. That write lands at the daemon after the exit resetAuto and re-pins the fans in manual — with the app gone, they stay pinned until the daemon watchdog reverts them.

Fix

The quit path now quiesces first, in order:

1. stop the monitor's ticks and reject new submits (a terminating flag guards the onFanCommand hop into the pump),
2. flush() — a new synchronous barrier on the pump's queue that blocks until every command submitted before it has executed (the barrier block itself drains, closing the append-vs-kick window),
3. only then does the exit resetAuto run, so nothing can supersede it.

The AppDelegate holds the AppState reference (handed over in ThermalForgeApp.init, same instance as the @StateObject) to reach the pipeline at quit time.

Testing

swift build + full swift test pass, including two new pump tests: flush returns only after in-flight and pending writes have executed, and the pump still serves submits made after a flush.