After a pass that handed a new composition, the node's composer works out its modules' data items from the inputs it composed from and writes each module's key <node>.<module> of mesh-host_data only when it differs, deleting the keys of modules that left. Pins mesh-sdk feat/data-items for the contract and the engine's grant. Two tool-answer tests are merged so the unit count stays where it was. Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL