A merged message or a preview without the objects gives the module none, naming the paths. Every other module keeps its
directory's tree. Module.ArtifactPaths is filled for the checker (the lead's interface).
The indexer holds no published list of predefined keys; each key a value names is taken as the value declares it.
No fingerprint input comes from the list: the gate and the controller still judge the value.
Fixtures are copied from the writer, never written by hand: four catalogue manifests at mesh-catalog a67f0196 and build-agent's at mesh-controller f2d7bc94.