The fit keeps the slope and discards the intercept, so the result counts from
the producer's boot. Tasks 4 and 7 compose it with ClockOffset::map, which is
correct, but the bare name invites passing it straight to a plot axis.
Also unwrapped the stalled-clock assertion from behind `if (fit.ready())` —
that branch never runs, so the test confirmed nothing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The jitter test fed a receive timestamp that went backwards (1001.02 then
1000.97), putting the second reading 1.03 s from the prediction — twice the
threshold, so not jitter under any reading. That is a digit slip for 1001.97.
It had been worked around by making the threshold one-sided, which passes the
test but never fires when the producer's clock steps forward: the prediction
stays ahead of the wall clock, the error stays negative, and the trace sits in
the future for the rest of the run. Restored std::fabs, corrected the test data,
and added the forward-jump case that the one-sided version silently failed.
Plan amended so the bad data does not come back.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds TimeBase.h/cpp with ClockOffset (latched wall-clock offset with
one-sided recalibration on positive drift only, so early-arriving packets
do not wobble the trace) and HrtRateFit (sliding-window OLS that recovers
an unknown hrt tick rate from receive timestamps). Also adds
TimeSignalScale() which maps UDPS type codes to seconds-per-count.
9 new tests, all 28 pass.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
