The builder agrees a language's toolchain from the three build seats'
toolchain-reported, kept in its state toolchains-heard (read back at its start),
forgets a node's on the node-engine seat's running with no fingerprint (stopped)
and never on a placement, says toolchain-agreed with its digests list only when
the agreed version changes; builder_toolchains and builder_toolchains_drop;
the manifest's reads of the build modules' toolchains are gone. The gate over
the assignments is now PlacedNodes, which only counts nodes.
Builds: design 47 G §492, §604, §546, §472, §574
Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ
