_script_command() split the configured command with a bare
shlex.split(), so a command string with unbalanced quotes crashed event
dispatch with a raw ValueError. The dispatcher-template twin a few
lines up already wraps the same call in try/except ValueError and
returns None so dispatch falls back cleanly.
Wrap the split the same way and return None, restoring parity between
the two paths.
Assisted-by: GitHub Copilot (model: claude-fable-5, autonomous)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>