data-workspace:
  GET /coordinate-async -> start a data task
  GET /coordinate-poll?runId=&since= -> raw transcript
  GET /coordinate-enriched?runId= -> transcript WITH artifact attachments
  POST /seed-data -> seed the DATA bucket (admin)
  POST /query -> proxy a SQL query to ClickHouse (serving layer)
  GET /tables -> list governed Iceberg tables + their state
  POST /tables/bootstrap -> create an empty governed Iceberg table (namespace + table)
  POST /promote -> validate schema + promote a table to curated
  GET /promotions/:id -> a promotion Workflow's status + outcome
  GET /maintenance -> the recorded maintenance sweeps
  GET /cost -> per-run usage attribution + catalog-op totals