Constant PICKER_CREATE_KIND_ID 

pub const PICKER_CREATE_KIND_ID: u32 = 201;

OR.5: CandidateData::Extension { kind_id } the picker stamps on its synthetic create row.

A distinct id rather than an index into routing_meta, because the create row’s payload is the live query — it changes on every keystroke, while routing_meta is written once per seat. Giving it its own kind keeps Picker::routing_for a lookup rather than a special case threaded through the sidecar.