Reads the Criteria table from the CST workbook (supports classic "Criteria" or "Search Tool Criteria Data (3)"), normalizes the table, and caches the result. Falls back to the installed workbook under inst/extdata/cst-workbook.xlsx on download failure.
Arguments
- download_only
Logical. If TRUE, bypasses the cache and package fallback and attempts to download the latest workbook directly from EPA, returning the requested sheet without updating the cache. Errors if the download fails.
- refresh
Logical. Only used when download_only = FALSE. If TRUE, ignore any cached copy and attempt to retrieve a fresh workbook (download, falling back to the package’s raw workbook on failure), then update the cache. If FALSE (default), return the cached table when available. Ignored when download_only = TRUE.