fix(node): give each node one push budget per traffic sync

After a sync tick disabled clients, the master pushed every affected
node inbound with its own 4 s timeout, a few at a time, and the job
served no other node until all were done; a hanging node could stall it
for as long as it had inbounds to report. Pushes are now grouped by node
and each node shares one budget, still a few inbounds at a time; what
does not make it stays for the reconcile, the node being dirty already.

internal/web/service/node_reset_undelivered_test.go

@@ -341,3 +341,33 @@ func TestNodeResetDeliveryDoesNotHoldTheRequestBehindASilentNode(t *testing.T) {
 		t.Fatalf("the reset request took %v behind a silent node", took)
 	}
 }
+
+// stallingUpdateRuntime never answers an inbound update until its context ends.
+type stallingUpdateRuntime struct{ fakeNodeRuntime }
+
+func (*stallingUpdateRuntime) UpdateInbound(ctx context.Context, _, _ *model.Inbound) error {
+	<-ctx.Done()
+	return ctx.Err()
+}
+
+// The sync job waits on these pushes before it serves any other node, so a hanging node
+// gets one push budget in all, not one per inbound it chose to report.
+func TestTrafficRemotePlansWaitOneBudgetPerNode(t *testing.T) {
+	setupBulkDB(t)
+	mgr := useTestRuntimeManager(t)
+	node := &model.Node{Name: "hanging", Address: "127.0.0.1", Port: 2096, ApiToken: "tok", Enable: true, Status: "online"}
+	if err := database.GetDB().Create(node).Error; err != nil {
+		t.Fatalf("create node: %v", err)
+	}
+	mgr.SetRuntimeOverride(node.Id, &stallingUpdateRuntime{})
+	plans := make([]trafficInboundUpdatePlan, 9)
+	for i := range plans {
+		ib := model.Inbound{Id: i + 1, Tag: fmt.Sprintf("in-%d", i), NodeID: &node.Id}
+		plans[i] = trafficInboundUpdatePlan{oldInbound: ib, newInbound: ib}
+	}
+	start := time.Now()
+	(&InboundService{}).applyTrafficRemotePlans(plans)
+	if took := time.Since(start); took > nodeClientPushTimeout+2*time.Second {
+		t.Fatalf("pushing %d inbounds to one hanging node took %v", len(plans), took)
+	}
+}