Module throttle_monitor 

2026-09-26: How much of each recent interval the clocks spent throttled, from successive ThrottleCounters reads (used by the TUI, tui/data/thermal.rs).

Owner: bench hardware. Invariants:

• A window is never reported for the first read or for a clock that did not advance.
• A thermal counter that went backwards makes the window’s thermal_frac None and thermal_active false, never a number.

The counters are cumulative, so one read says how much the box has ever throttled; the difference of two says what fraction of the interval the clocks were held. Sustained throttling and flapping in and out of it are different failures, so the monitor reports the fraction per window and the number of on/off transitions across its history (ThrottleMonitor::transitions).

SW power cap is not counted as throttling here, for the reason given on super::state::ThrottleActive::thermal; it has its own field, power_cap_frac.

Structs

ThrottleMonitor

2026-09-26: Rolling detector over successive counter reads.

ThrottleWindow

2026-09-26: One differenced observation of the throttle counters.