build-data

Legacy feature (has `data/state/` or `services/main-service/`)? Extend it in place per the legacy rules; don't migrate unless asked. Create the feature's `data/` layer: pure Data declarations, depending only on `@adobe/data` and the `data/` of features this one builds on. - `values/<type>/` — one namespace per Data type: a hand-written type, a schema pinned to it (`type _Pin = Assert<Equal<Schema.ToType<typeof schema>, <Type>>>`) when something needs one, and pure helpers, each with a test. - `components/<name>.ts` — one schema per file, scope spread from `Scope`, plus an `index.ts` barrel. Include implementation-only columns (tags, drag offsets). - `resources/<name>.ts` — one schema per file, `satisfies ResourceSchema`, plus a barrel. - `entities/<entity>.ts` — the spec-visible entity as a component-name tuple, with its type derived by `Database.EntityType`, plus a barrel. Create only the folders the feature needs. Gate: it compiles and the helper tests pass. The how is in the auto-loading `features/data/` rules and `global/namespace.md`.