index.js + index.d.ts re-exporting every collection’s <name>.json.
Two .d.ts modes: velite-style (TS/JS config, infer via
typeof import(..)) and self-contained (TOML, from schema).
dmc-schema descriptor -> TS type emitter for generated index.d.ts.
Unknown shapes fall back to unknown (build never fails on an
unrecognised descriptor).