chore(legal): IP/provenance verification pass for fragrance associations (pre-commercial gate)

[rvnminers-A-and-N]

Food-clearance data is cited to open-gov registers. The fragrance / aroma-only structure→odor associations from #208 come from general public flavor/fragrance chemistry knowledge (some via Claude Opus 4.8), resolved to public-domain PubChem structures — non-copyrightable facts (Feist), no proprietary compilation used. But the volume means this needs the standing pre-commercial diligence:

1. Per association, find ≥2 independent public sources (PubChem odor annotations, open-access literature, public patents, gov DBs).
2. Flag any association traceable only to a proprietary compilation (Good Scents / Leffingwell / FlavorDB) → find an independent public source or drop it.
3. Record source per molecule (provenance column).
4. Attorney sign-off before commercial sale.

Note: the JAFC 'Data-Driven Elucidation of Flavor Chemistry' dataset (MIT-repo but aggregates recognizable proprietary sources) stays out of the commercial edition — academic edition only. Documented in docs/SOURCES.md + docs/AROMA-AUDIT.md.