e973b2ce20
- Implemented `pcli project export` command to export project hierarchy as JSON. - Added `pcli project import` command to import project data from JSON. - Created user client to fetch user details for comment attribution. - Introduced new data structures for export and import processes. - Ensured name-based references in exports and handled conflicts during imports. - Added versioning and progress reporting for import operations. - Updated documentation and specifications for new features.