ADR 0627 §4: asks and asker leave mesh-sdk for operator-channel's client; the channel's benches stay as package channel

The gate's and the assigner's asks carry the router's ask as its JSON, so mesh-sdk names no type of a seat
defined whole; the ask's id, options, digest and an option's level are read by the gate, the assigner and the
teller through operatorchannelclient. ViewAnswerFits keeps the asking's check, from the key. The channel and
intake benches are not defined whole: their shapes move to go/channel (ADR 0625 §9).

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

go/testdata/seat-names.txt

@@ -1,4 +1,3 @@
-asks/asks.go: Seat
 buscompose/health_grants.go: mesh.seat.mesh-self-check.event.
 catalogue/artifact_sweep_seat.go: ArtifactSweepSeat
 catalogue/artifacts.go: ContainerImageRegistrySeat