helix-backup-audit-methodology-diff-plus-byte-plus-lint
Authoritative methodology for auditing Helix live runtime vs a backup: (1) diff -rq to enumerate file-path differences, (2) per-file byte comparison to flag size changes, (3) semantic categorization of size changes (enhanced / editorial compression / progressive-disclosure split), (4) run fusion-invariants-lint.py as final gate. Categories: identical (byte-perfect), enhanced (live≥backup), editorial-compression (≤800B diff, semantic equivalence), progressive-disclosure (SKILL.md shrinks but dir total grows). Zero in ‘true-loss’ category = audit pass.