Development record

The library long help says 'Every corpus verb but init exits 3 when there is no corpus.' (internal/surface/cli/source.go:98-99, docs/reference/cli/commands.md:3708-3709). But library sync-banlist --refresh with no corpus prints a one-line notice and exits 0 (source.go:557-561), as its own help and flag text say (commands.md:3906-3914).