Previous commit added the dump script + report but the actual jsonl was caught
by data/state/* gitignore. Add a targeted exception so the snapshot travels with
the repo — anyone who clones can do local filtering without re-hitting the API.
The data is regenerable (scripts/dump_listing_index.py is one-shot, ~1 min), but
pinning a dated snapshot lets us reason about "the state of the corpus on
2026-04-28" reproducibly. Future re-dumps overwrite the same path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>