docs(pmu): real-walk throughput = north of 6M walks/sec on Mac — sweep all live claims

This is a live, recomputable drift receipt — the on-chip proof of where this commit's work landed (in its authorized domain, out of it, or unplaced), sealed with a signature anyone can verify. It is the same receipt shipped in the on-commit email, hosted here so the claim is checkable on the open web. The full receipt (attestation, density panel, full commit message) publishes at /commit/0f4bb6879/ shortly after the commit lands.