verifyCommits flattened each check-in's whole S-tree against the published store through a resolver that died with the call, so a node near the root was re-fetched, re-inflated and re-parsed once per descendant check-in -- the cost a89b63ad05 removed from deriveCandidateHints, still present here.

repostate.SubManifestMemo already does this for Repository.flattenIfTree, and documents rebinding `inner` for reuse across walks; the log-only path had no way to hold one. flattenTreeFromLogMemo takes a caller-owned slot and the Verifier keeps one for the whole pass.

Byte-identical output. The win is commit count times inter-commit node sharing: 121 commits over 12,000 files touching 6 per commit, 9.88s to 8.19s. Wide per-commit churn destroys the sharing and is unchanged, never slower.

test 3495/3495, fmt. Issue #33. check-in: c120b93af5 user: dmestas tags: sub-manifest