Social Measurement Loop The weekly organic-social readback loop — the sibling of paid-measurement-loop for unpaid channels. It owns the measurement-integrity core of the ECHO O lever and feeds five O sub-items in echo-benchmark.md: declared period-stable denominators (the upstream of the ECHO-O1 veto), median-not-mean per-post rollups with organic and boosted separated, EMV excluded from any score, employee-excluded community-health metrics, and learnings written back to the next cycle. It owns the O lever's dictionary and loop but never computes the ECHO profile result — only social-quality-…