Builds: design 47 G §22, §116, §206, §271, §326, §338 (callers: steps the runner
and the indexer, drop the runner and the builder, kept-artifact the node-engines),
§24, §331 (step-ended.<node>, 128 MiB), §370, §373 (the ask carries the version and
each package member's digest), §203, §324 (acts build on the language).
Not yet in this commit, left as the dev branch built them and not read against the
lines: the accepted kind names (dev's 'step'; G-9 §415 names check.step, check.run,
delivery.step), the state rename detected-steps (G-9 §414).
Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ
