Root cause: DSM expects share paths (/dev) not volume paths (/volume1/dev).
The 408 errors were triggered by any additional field on the wrong path format.
- list_shares: use share["path"] directly (e.g. /dev), drop real_path from
additional — only volume_status remains
- list_dir: remove additional parameter entirely; table now shows name + type
(isdir is returned by default); update docstring to show share path examples
- client.py: remove diagnostic REQUEST and RAW ERROR stderr logging
- tests: update assertions to match share paths and two-column table output
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>