detect_clock estimated the bit clock from the *minimum* edge interval, so a few
stray sub-bit edges (which every real ADC capture carries) collapsed the estimate.
On a strongly-coupled, rail-clipping EM4100 the true half-bit of 32 dropped to ~3,
snapping the data clock to 8 and turning the ASK demod into all phase-error markers
— no config, no credential decoded.
Base the symbol on the shortest interval with real support (>=20% of the modal
count) instead of the raw minimum. Verified: clean synthetic still reads 32; the
hardware capture that broke it now clocks correctly. Live on a T5577 emulating
EM4100 00FFFFFFFF: DETECT decodes config 00148040, identify returns the credential.
Regression test reproduces the exact failure (sparse stray edges): old estimator
3.67 (dead demod), new 31.99.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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