The node key <node>.node is a write's commit: it names each placed module with its value's digest, the
module keys carry the value they replace until it lands, so a reader never composes half a write. Every
reader goes through PlacementKeys/PlacementsOf, which read the legacy placement.<node> too while the
change is delivered.
NodeHealth.Root: each such account's verdict (healthy, unhealthy with its way to root, unknown while the setuid search
runs), the module and resource declaring it. NodeHealth.Contract: the engine's statement contract, so a reader tells an
engine older than the judging. Test: a row in TestTheControlRecordsReadTheirWritersValues, read back byte-equal.
NetworkPart.Targets: the hub's machine for "hub", the machine whose tunnel address is each resolver's; empty where the
part is the machine's own. Filled by the node-engine from its tunnel's peers. Test: a row in
TestTheControlRecordsReadTheirWritersValues, read back byte-equal.