pages.config.json: primary page identity, navigation group, access expectation, scrolling, and mobile composition policy.
features.config.json: feature ownership, backend access class, data scope, and availability.
api.config.json: transitional inventory of current routes, generated from server.py and assigned to a feature owner.
data-fields.config.json: canonical data products, provider eligibility, intended use, and known blocked datasets.

During Stage 04 these files are contract inputs, not runtime replacements. Backend access in api_access.py remains authoritative until the HTTP governance phase switches it atomically. Frontend visibility remains a presentation concern and never grants backend access.

Regenerate the transitional API inventory after a route change:

python tools/build_api_registry.py
python tools/build_api_registry.py --check