test: the noise probe reads a measurement's band and HF reject

Five measurements on the same spiked `sine`, asking for corners 0, 50, 0, 0, 50 on one
channel: two windows under the (channel, fc) key, which is what exercises it.

    measure pkpk bare      noise=10.0 hf=0.0  value=2.987692   the stimulus, impulses included
    measure pkpk hf        noise=10.0 hf=50.0 value=1.990075   the waveform: pass one is filtered
    measure period noband  noise=0.0  hf=0.0  value=0.021290   supposed to be WRONG -- the control
    measure period band    noise=25.0 hf=0.0  value=0.200000   the band alone
    measure period hf      noise=0.0  hf=50.0 value=0.200000   the reject alone
    measure windows=2                                          the corner is part of the key

`pkpk hf` is the reading that says the filter reached *pass one* and not only pass two; a
value near 3 means it did not. `period noband` is deliberately the defect the band exists to
fix, and a future reader who "fixes" it has removed the check.

The band leg asks for **25 %** rather than the 10 % default, and that is arithmetic rather
than a workaround: the band is a share of the *window's* peak-to-peak, which with the
impulses in it is about 3, so 10 % is a half-band of 0.3 -- less than the 0.5 an impulse
moves the signal by. `MeasureOptions::noise_pct`'s own rationale says 10 % holds to a 0.3
interferer, and this mock's is 0.5, so the default could not clear it. The default band is
what the `period noband` and `period hf` legs are about.

verification.md now says the noise and measurement probes must not share a run: both push
onto `app.measures` and the later one would read the earlier one's rows.

docs/claude/probe-readings.md

@@ -1313,3 +1313,34 @@ buffer.
   means `a` is far too small, i.e. `dt` never arrived at the detector.
 - `state` is `2` (Done) or `4` (Capped) on every leg. `3` (Truncated) on more than one leg means the pump loop
   is being overtaken -- nothing to fix in the feature, but say so.
+
+The same probe then puts five measurements on the same spiked `sine` as **two windows** -- three legs at
+`hf=0` and two at `hf=50` -- and reads them back:
+
+```
+[noise-probe] measure pkpk bare      noise=10.0 hf=0.0  valid=1 value=2.987692
+[noise-probe] measure pkpk hf        noise=10.0 hf=50.0 valid=1 value=1.990075
+[noise-probe] measure period noband  noise=0.0  hf=0.0  valid=1 value=0.021290
+[noise-probe] measure period band    noise=25.0 hf=0.0  valid=1 value=0.200000
+[noise-probe] measure period hf      noise=0.0  hf=50.0 valid=1 value=0.200000
+[noise-probe] measure windows=2
+```
+
+- **`pkpk bare`** -- about **3.0**: the sine's 2 plus an impulse either way. The impulses dominate the
+  window's extremes, so this is the *stimulus*.
+- **`pkpk hf`** -- about **1.99** (`2/sqrt(1 + (5/50)^2)`): the *waveform*. This is the reading that says the
+  filter reached **pass one** and not only pass two; a value near 3 means it did not -- check `measure_scan`
+  is handed `w.scan_filter`, and that `filtered` disabled the buckets, since a bucket's aggregate is raw.
+- **`period noband`** -- about **0.021**, far below the true 0.2. **This one is supposed to read wrong**: it is
+  the control the other two are compared against, the defect the band exists to fix. "Fixing" it removes the
+  check.
+- **`period band`** -- exactly **0.200000**, the true period, from the band alone. Near `period noband` means
+  `noise_pct` is not reaching `measure_set_level`. The leg asks for **25 %** and not the 10 % default: the band
+  is a share of the *window's* peak-to-peak, which with the impulses in it is about 3, so 10 % is a half-band
+  of 0.3 -- less than the 0.5 an impulse moves the signal by, which is exactly what
+  `MeasureOptions::noise_pct`'s own rationale says (10 % holds to a 0.3 interferer).
+- **`period hf`** -- exactly **0.200000** with the band off: the reject alone. Near `period noband` means the
+  pole coefficient stayed at 1 -- check `measure_filter_set` was given a non-zero `dt`.
+- **`measure windows=2`** -- the five legs ask for corners `0, 50, 0, 0, 50` on one channel, which is two
+  distinct windows. **`windows=1` means the corner is not part of the key**: the five collapsed onto one walk
+  and two of them read a signal they did not ask for.