hvtiRdatabuild 0.2.4

• Master datasets. Six new functions snapshot, lift and correct the master
  datasets that study builds read. read_master_config() reads a master.yml
  declaring a master's key, alternate keys and parent. snapshot_master()
  freezes its SAS builds as parquet and records which parent release each was
  built from, read from the run's log first. lift_master() loads a snapshot
  into the warehouse behind key and full-parity gates and creates the master's
  view. backfill_corrections(), propose_correction() and
  decide_correction() keep an append-only record of corrections the view
  applies. The bulk functions dry-run by default. See
  vignette("master-datasets"). duckdb and tidyselect join Suggests.

• An analysis set names its own event column. hvtiRutilities 1.4.0 made
  study registration endpoint-neutral: register_data() no longer takes
  event or time, and study_config() no longer carries a study-wide
  cohort. write_analysis_set() had counted n_events and n_censored from
  that cohort, so under 1.4.0 every write failed. A set now declares event:
  (one of its vars) to get both counts, and an expect on either count
  without one stops with a message naming the missing key. A set with no
  event records n alone. A set that relied on the study-wide cohort needs
  the one-line event: added, which also changes its declaration hash, so
  read_analysis_set() asks for one rewrite.
  hvtiRdatabuild now requires hvtiRutilities 1.4.0 or later, since its tests
  and registration fixture use the endpoint-neutral register_data().

• snapshot_oracle() can snapshot a dataset too large for memory. The new
  chunk_rows argument reads the SAS dataset a chunk at a time and writes the
  chunks as row groups of one parquet file. It also records a SHA-256 of the
  SAS source beside the parquet checksum, and writes a .meta.json sidecar
  holding each column's label, SAS format and type, so that metadata survives
  into systems that cannot read R attributes. jsonlite joins Suggests. The
  source checksum now brackets the read, taken before and after; a mismatch
  removes the parquet and stops rather than write a snapshot of a file that
  changed underneath it.