The node agent's applies run through a runner its options name, so one integration test proves the bus module's first want takes the bus server over from the node's own composition without moving it, and a build that changes it replaces it once (ADR 0599 §4, §6)

cmd/mesh-host/nodeagent.go

@@ -508,7 +508,7 @@ func nodeAgent(ctx context.Context, opts options, signer ed25519.PublicKey, trus
 			// What this engine applied, kept on the machine and read at the start, so what runs is known before the node
 			// composes its own (issue 774).
 			Applied:  appliedStoreFor(opts.state),
-			Inactive: inactiveIn(&liveness.Exec{Run: apply.ExecRunner, System: builtFor}, heldBy(apply.WindowsIn(filepath.Dir(opts.state)))),
+			Inactive: inactiveIn(&liveness.Exec{Run: liveness.Runner(opts.run()), System: builtFor}, heldBy(apply.WindowsIn(filepath.Dir(opts.state)))),
 			Revisions: func(ctx context.Context, key string) ([]agent.Update, error) {
 				got, err := session.KVHistory(ctx, composedBucket, key)
 				if err != nil {