Name the node-engine's data items state, so mesh-host writes and disk-load reads one shape (ADR 0577)

The contract (state name, key form, value) is in delivery; buscompose grants the engine its own
node's keys of mesh-host_data and each node's disk-load a read of its own node's keys alone, the
same way the engine's other states are granted.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

go/buscompose/buscompose_test.go

@@ -99,7 +99,9 @@ func engineBeyond(user, g string) bool {
 		// And its own health report (issue 774).
 		strings.Contains(g, "KV_"+delivery.NodeHealthBucket) || g == "$KV."+delivery.NodeHealthBucket+"."+node ||
 		// And the provisions of its node's modules, read (novox/hq ADR 0570 clause 6).
-		strings.Contains(g, "KV_"+provisions.ProvisionsBucket)
+		strings.Contains(g, "KV_"+provisions.ProvisionsBucket) ||
+		// And its node's placed modules' data items, its own node's keys (novox/hq ADR 0577 clause 1).
+		strings.Contains(g, "KV_"+EngineDataBucket) || strings.HasPrefix(g, "$KV."+EngineDataBucket+"."+node+".")
 }
 
 // createsAnAccountsConsumer is the grants part's create and read of a durable consumer an account needs, by its stream
@@ -657,6 +659,8 @@ func healthChecks(t *testing.T) {
 		// ADR 0565 clauses 10, 11 (issue 1953 L5-S4): mesh-hand-acts reads the controller's log beside its own.
 		{"mesh-hand-acts", ControllerHandActs, true},
 		{"mesh-conditions", "mesh-healers.attempts", true}, {"mesh-conditions", HealersWould, false}, {"mesh-delivery-view", HealersWould, false},
+		// ADR 0577 clause 1: the node-engine's data items are disk-load's alone to read.
+		{"disk-load", delivery.EngineDataRead, true}, {"restic", delivery.EngineDataRead, false},
 	} {
 		granted, _ := ReadsAnnouncedBy(c.reader, []string{c.read}, announced)
 		if (len(granted) == 1) != c.may {
@@ -686,8 +690,9 @@ func healthChecks(t *testing.T) {
 			Reads: []string{delivery.SeatHoldersRead}},
 		{Module: delivery.AssignerModule, State: []Bucket{bucket(delivery.AssignerModule, delivery.SeatHoldersState)}},
 		// ADR 0571 clause 3: disk-load keeps the readings; the backup holder reads them.
-		{Module: "disk-load", State: []Bucket{bucket("disk-load", "readings")}},
-		{Module: "restic", Reads: []string{"disk-load.readings"}, State: []Bucket{bucket("restic", "good")}},
+		// ADR 0577 clause 1: and it reads its own node's keys of the node-engine's data items, which restic may not.
+		{Module: "disk-load", State: []Bucket{bucket("disk-load", "readings")}, Reads: []string{delivery.EngineDataRead}},
+		{Module: "restic", Reads: []string{"disk-load.readings", delivery.EngineDataRead}, State: []Bucket{bucket("restic", "good")}},
 		// ADR 0571 clauses 1, 9: the indexer reads the builder's log through its own consumer; the catalogue module asks
 		// the builder's tool.
 		{Module: delivery.BuilderModule, Logs: []Log{{Module: delivery.BuilderModule, Name: delivery.BuilderLog, MaxAgeDays: 30}}},
@@ -708,7 +713,8 @@ func healthChecks(t *testing.T) {
 		"a.mesh-vault": {"$JS.API.DIRECT.GET.KV_mesh-provisioner_provisions.$KV.mesh-provisioner_provisions.a.keycloak.postgres-database",
 			"$JS.API.DIRECT.GET.KV_mesh-provisioner_plans.$KV.mesh-provisioner_plans.a.keycloak"},
 		"a.mesh-hand-acts": {"$KV.mesh-hand-acts_warrants.mesh-config.ask-1", "mesh.log.mesh-hand-acts.acts.act-1"},
-		"a.disk-load":      {"$KV.disk-load_readings.a.pg.data"},
+		"a.disk-load": {"$KV.disk-load_readings.a.pg.data", "$JS.API.DIRECT.GET.KV_mesh-host_data.$KV.mesh-host_data.a.pg",
+			"$JS.API.CONSUMER.CREATE.KV_mesh-host_data.c1.$KV.mesh-host_data.a.*"},
 		"provisioner.a": {"$JS.API.DIRECT.GET.KV_mesh-provisioner_plans.$KV.mesh-provisioner_plans.a.keycloak",
 			"$JS.API.CONSUMER.CREATE.KV_mesh-provisioner_plans.c1.$KV.mesh-provisioner_plans.a.keycloak",
 			// Every machine's plans, as the client V3 watches them (issue 774, 2026-10-30).
@@ -748,7 +754,8 @@ func healthChecks(t *testing.T) {
 		"a.mesh-vault": {"$KV.mesh-provisioner_provisions.a.keycloak.postgres-database", "$KV.mesh-provisioner_plans.a.keycloak",
 			"mesh.seat.mesh-artifact-sweep.event.artifacts-gone"},
 		// Each writes its own state alone, and these users are composed.
-		"a.disk-load":             {"$KV.restic_good.a.pg.data"},
+		"a.disk-load": {"$KV.restic_good.a.pg.data", "$KV.mesh-host_data.a.pg",
+			"$JS.API.DIRECT.GET.KV_mesh-host_data.$KV.mesh-host_data.b.pg", "$JS.API.CONSUMER.CREATE.KV_mesh-host_data.c1.$KV.mesh-host_data.b.*"},
 		"a.mesh-delivery-builder": {"$KV.disk-load_readings.a.pg.data"},
 		// It reads every machine's plans (a provider's consumers are bound there, ADR 0373) but writes none, nor another
 		// machine's needs, which it keeps for the client before V3 until the lease write.
@@ -756,7 +763,7 @@ func healthChecks(t *testing.T) {
 		// Only the assigner writes seat-holders.
 		"a.artifact-store-tools": {"$KV.mesh-delivery-assigner_seat-holders.mesh-broker"},
 		// Only disk-load writes its readings.
-		"a.restic":   {"$KV.disk-load_readings.a.pg.data"},
+		"a.restic":   {"$KV.disk-load_readings.a.pg.data", "$JS.API.DIRECT.GET.KV_mesh-host_data.$KV.mesh-host_data.a.pg"},
 		"a.postgres": {"$KV.mesh-provisioner_provisions.a.keycloak.postgres-database", "$KV.mesh-provisioner_plans.a.keycloak"},
 		// Nor mesh-hand-acts' log and warrants, which it alone writes (ADR 0565 clause 10).
 		"a.mesh-healers": {"$KV.mesh-conditions_conditions.x", "$KV.mesh-conditions_takeover.switch",