Each source module now exports a brands[] array:
- motousher: 44 brands (full list from brands.js)
- dirtstreet: 5 brands (SC Project, Evotech, etc.)
- retrorides: 10 bike brands (BMW, Ducati, Aprilia, etc.)
- kyt: KYT
- brocks-performance: Brock's Performance
- yuasa: Yuasa
listSources() passes brands[] through in the API response so the
frontend can render the per-source brand list without a separate call.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>