Initial release.
rais_available() lists every archive published on the PDET/MTE FTP
server, with size, modification date and edition (final, partial,
legacy).rais_files() resolves offline which archive holds a state in a year
(one file per state up to 2017, regional files from 2018) and rais_ufs()
gives the state table behind it.rais_download() fetches the archives into an idempotent local cache that
mirrors the server layout (rais_cache_dir(), rais_cache_list(),
rais_cache_clear()).rais_read() stream-reads a .7z archive, filtering by state and
selecting columns chunk by chunk, detecting the file generation (; with
decimal comma up to the RAIS 2022, , with decimal point from the RAIS
2023) and mapping both to the same normalized column names;
rais_fetch() combines download and read for several years.rais_stock() consolidates the stock on 31 December, admissions,
separations and December payroll by any grouping.rais_layout() documents the columns of the employment and establishment
files, with the two header spellings of each.inst/extdata (both generations, employment and
establishments, plus a pre-2018 state file) allow every reading function
to be tried offline.