- Filenames may contain spaces: quote on the command line; filename
lists use a standalone "/" separator; unseparated names that do not
exist are rejoined into names that do (announced); leading ~ expands.
- Without -o, output is written to the input file's directory; -o fully
specifies the output directory and basename.
- "Word not parsed" warnings now appear without -v, only for text that
survives removal, with correct line numbers.
- New tst/filename_test.sh regression suite.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>