docs: the measures panel's frame is read by switch_on/reset_sensitive

The dump line's two new fields, and what either of them disagreeing with
[stats-probe] on= means: a .ui that lost the widget, or the wiring to it. pane_rows is
what proves the readout rows landed in the frame's measures_list.

docs/claude/probe-readings.md

@@ -196,7 +196,7 @@ Two lines of the self-check output are assertions in disguise:
   "the app placed them and they are on screen".
 - `[measures-probe]` + the dump's `measure N: 'sig' type thr=..% above=D show=D -> ok|invalid value text=[..]
   [duty=..] [marks=..]` and `measures pane: n=N revealed=D marks_shown=M pane_rows=R pane_w=W
-  pane_h=H`
+  pane_h=H switch_on=X reset_sensitive=Y`
   (stderr, `UDPSCOPE_PROBE_MEASURES_MS`) — adds one measurement of every type on the first
   plottable signal and lets the tick compute them, so what it prints is what a user reads.
   On the test stream's 1 Hz ±1 sine the values must be: average ≈ 0, `top` ≈ 0.64 and
@@ -213,7 +213,10 @@ Two lines of the self-check output are assertions in disguise:
   *and* a marker at the first sample that reached it — two level marks at both extremes was
   the bug), `time:A,time:B` for pulse/period/frequency. `text=` is the pane's own string with
   its unit, so `frequency` must read `Hz` (not the signal's unit), `period`/`pulse duration`
-  seconds, and the rest the channel's unit. `marks_shown` counts two per shown measurement
+  seconds, and the rest the channel's unit. `switch_on` and `reset_sensitive` are the panel's *frame* read back: the switch widget against
+  `measure_stats_on`, which the code drives, and the Reset button that follows it. Either disagreeing with
+  `[stats-probe] on=` is a `.ui` that lost the widget, or lost the wiring to it; `pane_rows=R` is what
+  proves the readout rows landed in the frame's `measures_list` rather than nowhere. `marks_shown` counts two per shown measurement
   (a min/max showing both its marks counts two of its own). `measures window:` is the
   timeliness assertion -- the window the numbers were computed over against the one on screen.
   **The reading that must hold is `marks_in_window=K/K`**: every *time* mark inside the window