The checker's go.mod and go.sum conflicted on the mesh-sdk pin (checker lane 9cb4d59, builder lane e76a5a3): every
module touched is pinned to the sdk lane's newest head d1af87a until the final SDK head.
Moves the mesh-sdk pin to feat/r4e-sdk 9cb4d59, which accepts such a key and names delivery.WaitsFor; the builder's
package wait now uses that shared prefix (B7).
Pins mesh-sdk feat/r4e-sdk a90f523 (R4e's group member). A trunk key's builds are asked to publish; a build answering
no reference fails the key 'not stored:', and a step's own 'not stored:', 'not pinned:', 'version taken:' or
'refused kind:' opens the key's error.
jschoubben