A want that names a node in kept-on, for an artifact its parts name, is fetched through kept-artifact of that node's build seat and
read as an object on the bus, checked against the digest; with no kept-on it is fetched from the store, and the builder's builds
are read no more (the apply hook, the fetch and the object read from bc8fbc7, its node and fingerprint from the want).
Builds: design 47 G §271, §526, §421 (A-50)
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h
jschoubben
5173f2a31c