[management/client] create job channel between management and client (#4367)

* new bi-directional stream for jobs

* create bidirectional job channel to send requests from the server and receive responses from the client

* fix tests

* fix lint and close bug

* fix lint

* clean up & fix close of closed channel

* add nolint:staticcheck

* remove some redundant code from the job channel PR since this one is a cleaner rewrite

* cleanup removes a pending job safely

* change proto

* rename to jobRequest

* apply feedback 1

* apply feedback 2

* fix typo

* apply feedback 3

* apply last feedback

client/internal/engine.go

@@ -478,6 +478,7 @@ func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL)
 
 	e.receiveSignalEvents()
 	e.receiveManagementEvents()
+	e.receiveJobEvents()
 
 	// starting network monitor at the very last to avoid disruptions
 	e.startNetworkMonitor()
@@ -947,6 +948,33 @@ func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
 	return nil
 }
 
+func (e *Engine) receiveJobEvents() {
+	go func() {
+		err := e.mgmClient.Job(e.ctx, func(msg *mgmProto.JobRequest) *mgmProto.JobResponse {
+			// Simple test handler — replace with real logic
+			log.Infof("Received job request: %+v", msg)
+			// TODO: trigger local debug bundle or other job
+			return &mgmProto.JobResponse{
+				ID: msg.ID,
+				WorkloadResults: &mgmProto.JobResponse_Bundle{
+					Bundle: &mgmProto.BundleResult{
+						UploadKey: "upload-key",
+					},
+				},
+			}
+		})
+		if err != nil {
+			// happens if management is unavailable for a long time.
+			// We want to cancel the operation of the whole client
+			_ = CtxGetState(e.ctx).Wrap(ErrResetConnection)
+			e.clientCancel()
+			return
+		}
+		log.Debugf("stopped receiving jobs from Management Service")
+	}()
+	log.Debugf("connecting to Management Service jobs stream")
+}
+
 // receiveManagementEvents connects to the Management Service event stream to receive updates from the management service
 // E.g. when a new peer has been registered and we are allowed to connect to it.
 func (e *Engine) receiveManagementEvents() {