Executable spec for the audit follow-up on the identity-index cycle:
once one full repair walk has run over a same-identity-twin store (two
blueprints sharing one identity id, distinct content ids), a further
scan-triggering lookup must leave blueprint_identity_index.jsonl's line
count unchanged while the twin identity still resolves. RED against the
current per-entry snapshot comparison (appends one alternating line per
scan-triggering lookup while twins coexist).
refs #191
claude
35865bb934