An id whose canonical stem contains its legacy stem as a prefix (parent
dir name == file stem, e.g. .claude/CLAUDE.md) re-matched the legacy
branch every build and grew another stem segment, defeating the
same_topology/no_change short-circuits and churning graph.json +
clustering on every zero-delta update. Skip an id that already carries
its canonical stem (mirrors graph_has_legacy_ids); genuine legacy
migration still applies. Also records the #1889/#1918 query-scoring perf
work in the changelog.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>