Make the second merge check pass: the gate's mesh has a chain of its own; the tests follow delivery 2's meaning (issues 1121, 1108, 1109)

The merge gate raises the snapshot's mesh in a throwaway store and now gives it a chain in memory, since the chain lives only on the bus. A module with no commit is carried by no send (a send is read from the commits on the assignments' keys), so the grants step flags only a module with a commit as newly assigned. The tests that sent a module with no build record one, the merge test waits for the merges' consumer before publishing and for the last look of a window before the next test, the pending test follows a chain that deletes nothing, and a wait's settling is a value of its key.

cmd/mesh-controller/data_integration_test.go

@@ -56,13 +56,19 @@ func TestNatsUnassigningIrreplaceableDataRetiresItAndAnEmptyReplacementIsUrgent(
 	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
 		t.Fatal(err)
 	}
-	register(t, open, catalogue.Manifest{Module: "keeper", Version: "1",
-		Claims: []catalogue.Claim{{Name: catalogue.BackupSeat, Scope: catalogue.ScopeNode, Serves: []string{"backed-up", "now", "restore"}}}})
+	// Built from a commit, so that a send carries them: a holder is asked only of what the machine was sent (issue 1109).
+	built := inventory.Source{BuiltFrom: "c1"}
+	if err := inv.RegisterModule(ctx, catalogue.Manifest{Module: "keeper", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.BackupSeat, Scope: catalogue.ScopeNode, Serves: []string{"backed-up", "now", "restore"}}}}, built); err != nil {
+		t.Fatal(err)
+	}
 	house, err := catalogue.ParseManifest([]byte(houseManifest))
 	if err != nil {
 		t.Fatal(err)
 	}
-	register(t, open, house)
+	if err := inv.RegisterModule(ctx, house, built); err != nil {
+		t.Fatal(err)
+	}
 	if _, err := assign(ctx, open, "laptop", "house"); err == nil {
 		t.Fatal("irreplaceable data was assigned to a machine with nothing to back it up")
 	}