Expand description
CmdTableShell — owns the typed Table<Cmd, EmptyEntity> and exposes
it across the TableShell boundary.
Value = CborValue end-to-end, so list_vista_values forwards the
table’s records unchanged. Relations are followed the built-in way:
get_ref forwards to the wrapped table’s Table::get_ref_from_row,
which reads the join value out of the parent row and pins the target
table with a plain eq-condition — the same path csv / sqlite use.