- Made map_error_to_exit_code() function public in hash.rs so it can be
called from main.rs
- Added test file test_hash_exit_codes.rs to verify exit code behavior
- Updated verification note with current implementation status
The hash subcommand was already implemented but map_error_to_exit_code
was private, causing a compilation error. This fix resolves the issue.
Related: pdftract-3954u
