hvtiRdatabuild 0.2.2

• Documentation no longer points dw_pull() users at a
  building-a-study-dataset vignette that does not exist, and the SAS migration
  guide no longer lists the shipped dw_connect() and dw_pull() as future
  work. Prose across the README, vignette and reference pages was tightened.

• The SAS migration guide now treats bd.SAStoR.sas outputs as general
  downstream data contracts rather than exports owned by their first consumer.
  It shows how the final selection becomes a shared analysis set while variable
  derivation remains in the build layer.

• Analysis-set declarations now reject duplicate variables and require every
  expected row/event count to be one non-negative whole number. This prevents
  duplicate parquet columns from being silently renamed and fractional counts
  from matching after integer truncation.

• Analysis sets resolve their outputs through the study's logical datasets
  directory, preserving numbered new studies and adopted legacy layouts.