Registry (Forgejo) + memory-api clients under m2_market_indexer.client, with
memory-api paths/creds as env-overridable constants (config.py). reindex.py
drops market:catalog and rebuilds from published listings on main, skipping
schema-invalid ones. watch.py polls the registry tip commit against a cached
state.json and upserts changed/new published listings, deletes delisted ones.
