feat(blog): 'The Flip of the Flip' — our best evidence improved away (canonical A–L)

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/86d531c0a/ shortly after the commit lands.