Finding 1: strip trailing [digits] array-element suffix from Signal so one calibration entry covers an entire array signal, matching the C++ strchr truncation and the JS equivalent. Finding 2: after the 16-byte Unit truncation, drop any trailing partial UTF-8 rune so json.Marshal never emits replacement characters; keeps byte limit in sync with C++ strncpy(u, unit, kMaxUnitLen). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>