build-service-database

Legacy feature (has `data/state/` or `services/main-service/`)? Extend it in place per the legacy rules; don't migrate unless asked. Skip if the feature has no services. Create `ecs/services/service-database.ts` (extends the previous layer), registering each `services/` service's `create` under its `Services` key, plus any database-bound factories (one per file + barrel) for services that read observables or call transactions. Pin with `Assert<Equal<ServiceDatabase["services"], Services>>`. Give the implementation base fakes for services whose `create` throws. The how is in the auto-loading `features/ecs/services.md` rule.