Pass input files and capture output from a macOS Shortcuts automation using the shortcuts command-line tool's -i/-o flags

Steps

1. Run a shortcut by name from Terminal or a script with `shortcuts run "Combine Images"` (quote or escape names containing spaces)
2. Feed files into the shortcut with `-i`/`--input-path`, which accepts space-delimited absolute or relative paths or wildcards, e.g. `shortcuts run "Combine Images" -i ~/Desktop/*.jpg`
3. Capture the shortcut's result to disk with `-o`/`--output-path`, e.g. `shortcuts run "Combine Images" -i ~/Desktop/*.jpg -o ~/Desktop/combined.png`
4. Control the output's file type explicitly with `--output-type` (a Uniform Type Identifier) when piping output onward instead of writing to a named file
5. Check the process exit code — `shortcuts` exits `0` on success and `1` on error — to drive branching logic in wrapper scripts
6. Discover and preview automations before scripting them with `shortcuts list` (optionally `-f <folder>` or `--folders`) and `shortcuts view "Name"`, which opens the shortcut in the editor