Item 3: seatgen -check no longer names go/seats/nodebuildimage/acts_test.go (not written by the generator); the
test moves to the domain SDK's buildstep, which already reads the build seats' definitions. mesh-delivery-pipeline
no longer imports meshmoduleassigner.
Builds: design 47 G §324, §397
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h