One application-facing crate: notebook discovery (notebook::discover), the
SQLite replica with reconciliation, assets and recovery at the crate root,
embedded SMB access behind the smb feature (notebook::smb, including the
SmbRemote adapter), and the onestore-diagnostic bridge as a binary. Tools,
fuzz targets and documentation follow the new paths; the diagnostic binary
keeps its name for the Python tooling.

Validation: 457 workspace tests (nextest), 5 README doctests, Clippy and
fmt; the fuzz workspace builds.

Assisted-by: claude-fable-5.1