v0.16.2: safer setup errors and current notebook chat requests

Fixed

• Empty or whitespace-only MCP client config files can now be initialized. Malformed JSON and TOML files remain untouched and are reported clearly. nlm setup list continues past an unreadable client config, while nlm setup add and nlm setup remove show the affected path instead of a traceback (#400).
• Notebook chat sends the current 9-slot consumer request while preserving Enterprise behavior (#398). Live checks covered fresh conversations, follow-ups, selected sources, and citations. The previous request format also worked during verification, so treat this as a compatibility update rather than a confirmed fix for a production failure.

Credits

Thanks to @pengqun for #400 and the report in #399, and to @saariuslystoned for #398.