🔧 Turn a watch reference number into full specs (caliber, case, dial) as JSON

If you build anything around watch data — a marketplace, a valuation tool, an insurance
quoting flow, a collection tracker — you eventually hit the same wall: you have a
reference number (126500LN-0001, scraped from a listing or copied off an invoice)
and you need the spec sheet behind it — movement/caliber, case material, dimensions,
water...