test(nodes): give the DistributedBackendManager fixtures a system state (#12877)

The disable-backend-install switch (#12754) makes InstallBackend and
UpgradeBackend read d.systemState.DisableBackendInstall. The test
fixtures build the manager as a struct literal or through
NewDistributedBackendManager with an empty ApplicationConfig, so
systemState is nil and every install and upgrade spec panics with a nil
pointer dereference.

Set a zero-value SystemState in each fixture. That keeps installs
allowed, which is what these specs expect.

Assisted-by: Claude Code:claude-haiku-5-5

Co-authored-by: Ettore Di Giacinto <mudler@localai.io>

core/services/nodes/managers_agent_node_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/mudler/LocalAI/core/services/messaging"
 	"github.com/mudler/LocalAI/core/services/testutil"
+	"github.com/mudler/LocalAI/pkg/system"
 )
 
 // Agent workers do not subscribe to the backend.* subjects, so asking one to
@@ -38,9 +39,10 @@ var _ = Describe("Backend listing across mixed node types", func() {
 		Expect(err).ToNot(HaveOccurred())
 		mc = newScriptedMessagingClient()
 		mgr = &DistributedBackendManager{
-			local:    stubLocalBackendManager{},
-			adapter:  NewRemoteUnloaderAdapter(nil, mc, 3*time.Minute, 15*time.Minute),
-			registry: registry,
+			local:       stubLocalBackendManager{},
+			adapter:     NewRemoteUnloaderAdapter(nil, mc, 3*time.Minute, 15*time.Minute),
+			registry:    registry,
+			systemState: &system.SystemState{},
 		}
 		ctx = context.Background()
 	})

core/services/nodes/managers_distributed_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/mudler/LocalAI/core/services/messaging"
 	"github.com/mudler/LocalAI/core/services/testutil"
 	"github.com/mudler/LocalAI/core/services/workerctl"
+	"github.com/mudler/LocalAI/pkg/system"
 )
 
 // scriptedMessagingClient maps a NATS subject to a canned reply payload
@@ -311,9 +312,10 @@ var _ = Describe("DistributedBackendManager", func() {
 		mc = newScriptedMessagingClient()
 		adapter = NewRemoteUnloaderAdapter(nil, mc, 3*time.Minute, 15*time.Minute)
 		mgr = &DistributedBackendManager{
-			local:    stubLocalBackendManager{},
-			adapter:  adapter,
-			registry: registry,
+			local:       stubLocalBackendManager{},
+			adapter:     adapter,
+			registry:    registry,
+			systemState: &system.SystemState{},
 		}
 		ctx = context.Background()
 	})
@@ -655,7 +657,7 @@ var _ = Describe("DistributedBackendManager", func() {
 				// mgr in the outer BeforeEach has progressSink=nil so the
 				// pre-existing specs keep verifying the no-sink behavior.
 				sink = &recordingProgressSink{}
-				appCfg := &config.ApplicationConfig{}
+				appCfg := &config.ApplicationConfig{SystemState: &system.SystemState{}}
 				mgr = NewDistributedBackendManager(appCfg, nil, adapter, registry, sink)
 				// stubLocalBackendManager mirrors the production behaviour
 				// where the frontend node rarely has the backend installed

core/services/nodes/noroute_reactions_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mudler/LocalAI/core/services/messaging"
 	"github.com/mudler/LocalAI/core/services/testutil"
 	"github.com/mudler/LocalAI/core/services/workerctl"
+	"github.com/mudler/LocalAI/pkg/system"
 )
 
 // These specs pin the reactions the seams contract allows on ErrNoRoute: the
@@ -139,9 +140,10 @@ var _ = Describe("ErrNoRoute reactions", func() {
 
 		BeforeEach(func() {
 			mgr = &DistributedBackendManager{
-				local:    stubLocalBackendManager{},
-				adapter:  adapter,
-				registry: registry,
+				local:       stubLocalBackendManager{},
+				adapter:     adapter,
+				registry:    registry,
+				systemState: &system.SystemState{},
 			}
 		})