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.