Build modules take asks only within their node's build hours

mesh-build-go, -node and -image declare build-hours (node=HH:MM-HH:MM in the node's local time,
empty = any hour) and hand it to the SDK puller (the operator, 2026-10-26: g14 builds only from
18:00 to 06:00); their SDK pin moves to mesh-sdk d00dac1, which has it.

modules/mesh-build-node/cmd/mesh-build-node/asks_test.go

@@ -95,6 +95,13 @@ func TestManifestTakesTheBuildCapacity(t *testing.T) {
 	if got := buildstep.NodeCoresPerStep(moduleDir+"/files/settings.json", 0, nil)(); got != buildstep.DefaultCoresPerStep[delivery.AskNode] {
 		t.Errorf("the settings template holds cores-per-step %g", got)
 	}
+	// And the build hours (the operator, 2026-10-26): a setting of their own, empty by default (any hour), in the template.
+	if hours := string(doc.Config[buildstep.BuildHoursSetting].Default); hours != `""` {
+		t.Errorf("the build-hours default = %s, want empty", hours)
+	}
+	if w, fault := buildstep.NodeBuildHours(moduleDir+"/files/settings.json", "g14", t.Errorf)(); w != nil || fault != "" {
+		t.Errorf("the settings template holds build hours %v (%s)", w, fault)
+	}
 	var capacity string
 	_ = json.Unmarshal(doc.Config[buildstep.CapacitySetting].Default, &capacity)
 	if capacity != buildstep.DefaultCapacities {