Design 47 *A module's registration*, "No part fixes a name" (b229f5c4 lines 482-485): the indexer finds
the build modules from the seat list's acts and the manifests, after the gate is made, so the gate takes
them by UseModules and passes its reports on again. Row in TestToolchainGate: a module given later passes
on at the assignments only once given (fails without UseModules).
Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ
Builds: design 47 G §364, §428, §535