The client create/edit form left `group` out of the request payload, so choosing a group in the form was silently dropped (bulkAdd from the Groups page still worked because it writes the column directly). Add `group` to the payload next to `comment`.
SyncInbound also overwrote group_name unconditionally; a group set via bulkAdd is never pushed to the node, so the next node snapshot — which lacks it — wiped the column. Keep group sticky (only overwrite when the incoming value is non-empty); group is only ever set/cleared via the Groups page. Preserve comment for node clients during snapshot sync the same way. Add tests.
