Compose each machine in the merge gate with its engine's contract, so moved modules are handed there as on the mesh (issue 969)

cmd/mesh-controller/facts.go

@@ -287,6 +287,12 @@ func gatherFacts(ctx context.Context, open *stores, busVersion string) (snapshot
 			return snapshot.Facts{}, err
 		}
 		m.Architecture, m.Kernel = reported.Architecture, reported.Kernel
+		// Whether its node-engine takes handed files is its contract (issue 969).
+		if stated, had, err := inv.HealthOf(ctx, n.Name); err != nil {
+			return snapshot.Facts{}, err
+		} else if had {
+			m.Contract = stated.Contract
+		}
 		outward, err := inv.OutwardLinksOf(ctx, n.Name)
 		if err != nil {
 			return snapshot.Facts{}, err

cmd/mesh-controller/merge_gate.go

@@ -1017,6 +1017,13 @@ func raiseFromFacts(ctx context.Context, open *stores, f snapshot.Facts, shelf m
 			"kernel": m.Kernel, "capabilities": caps}); err != nil {
 			return notes, err
 		}
+		// What its node-engine takes, as the mesh composes it today (issue 969): without the statement the gate
+		// composes a moved module the old way on a machine the mesh hands it to.
+		if stated, ok := standInHealth(m, f.Taken); ok {
+			if _, err := inv.RecordHealth(ctx, stated); err != nil {
+				return notes, err
+			}
+		}
 		for _, record := range []func(context.Context, string, string) error{inv.RecordSealingKey, inv.RecordOverlayKey} {
 			key, err := standInKey()
 			if err != nil {
@@ -1355,3 +1362,12 @@ func firstOr(items, otherwise []string) string {
 	}
 	return "it says nothing more"
 }
+
+// standInHealth is the statement the gate gives a machine of the snapshot so that it composes as the mesh does:
+// only its contract, which says whether it takes handed files (issue 969). False for a snapshot that carries none.
+func standInHealth(m snapshot.Machine, taken time.Time) (inventory.NodeHealth, bool) {
+	if m.Contract == 0 {
+		return inventory.NodeHealth{}, false
+	}
+	return inventory.NodeHealth{Node: m.Name, Contract: m.Contract, SaidAt: taken, HeardAt: taken}, true
+}

cmd/mesh-controller/merge_gate_handing_test.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	snapshot "github.com/novox/mesh-controller/internal/facts"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// Issue 969: the gate composes a machine as the mesh does, so a moved module is handed where the machine takes
+// handed files and composed the old way where it does not.
+func TestIssue969TheGateGivesAMachineItsContractSoItTakesHandedFiles(t *testing.T) {
+	taken := time.Date(2026, 10, 16, 12, 0, 0, 0, time.UTC)
+
+	stated, ok := standInHealth(snapshot.Machine{Name: "f35", Contract: link.HandedContract}, taken)
+	if !ok || !takesHanded(stated, ok) {
+		t.Fatalf("a machine whose engine takes handed files must be given that in the gate: %+v, %v", stated, ok)
+	}
+	old, ok := standInHealth(snapshot.Machine{Name: "e12", Contract: link.HandedContract - 1}, taken)
+	if !ok || takesHanded(old, ok) {
+		t.Fatalf("a machine whose engine is older must not take handed files: %+v, %v", old, ok)
+	}
+	none, ok := standInHealth(snapshot.Machine{Name: "d01"}, taken)
+	if ok || takesHanded(none, ok) {
+		t.Fatalf("a snapshot that carries no contract states nothing: %+v, %v", none, ok)
+	}
+}

cmd/mesh-controller/plan.go

@@ -1126,7 +1126,13 @@ func engineTakesHanded(ctx context.Context, inv *inventory.Inventory, node strin
 	if err != nil {
 		return false, err
 	}
-	return had && stated.Contract >= link.HandedContract, nil
+	return takesHanded(stated, had), nil
+}
+
+// takesHanded is whether a machine's newest statement (had: it ever stated one) is of an engine that writes a
+// filled file on the provisioner client's word alone.
+func takesHanded(stated inventory.NodeHealth, had bool) bool {
+	return had && stated.Contract >= link.HandedContract
 }
 
 // provisionerAccount is the account the provisioner's client runs as on this machine (novox/hq ADR 0349 §4): the user