- resolveActivityTarget uses 'targetId'/'targetPath' for all types
(note, file, folder) instead of type-specific property names
- openActivityTarget for files: resolves the file node via
GetNodeDetail, navigates to its parent folder in the Files tab,
then auto-previews the file if it's a previewable type
- For root-level files (no parent_id): loads root items
- Removed spurious OpenFolder(targetPath) call that silently failed
because OpenFolder expects a node ID, not a filesystem path