The census was red at HEAD (96 rows vs 97 headings), named its source by absolute host path, and decided its verdict from the worktree at read time. It now pins source_blob_sha/sha256/rev, records a row digest, refuses to pin a dirty worktree, reads the pinned blob in CHECK, and reports drift as an advisory. 9 selftest cells; the non-decay claim is measured on real commits.