Verified on dev: the tr account serves NOT_LOGGED_IN_DEMO for Hyundai/Kia/Nissan
parts (browse-only), while the de (account 2) subscription is licensed and returns
real data (de: 266 Hyundai / 169 Kia models, non-demo, ~88/64 drill rows). Route
every P4 fetch for these brands to de in fetchP4Page (+ resolveAccount), and ensure
the de service token is authorized. Existing tr-coded catalog_vehicles must be
re-seeded so they carry de catalog codes (ops step on deploy).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>