Scans all custom data folders created by calc_pg() and prints a summary
of each configuration. Returns an indexed list of pg_config() objects
for direct programmatic use.
Value
An invisible named list of pg_config objects, one per custom folder.
Configs are indexed by position; use [[i]] to select one.
Examples
if (FALSE) { # \dontrun{
customs <- pg_list_custom()
# [1] abc123/xyz789: nrow=360, ncol=720, 1850-12-31 to 2025-08-26, 3 vars
read_pg_static(config = customs[[1]])
calc_pg("new_var", config = customs[[2]])
} # }