test: cover dispatch loss and workflow commit fault boundaries

sdk/go/worker_integration_test.go

@@ -53,6 +53,9 @@ type workerFaultGateway struct {
 	target              atomic.Value
 	dropOffline         atomic.Bool
 	dropCancel          atomic.Bool
+	holdAssignment      atomic.Bool
+	assignmentsHeld     chan WorkerAssignment
+	releaseAssignment   chan struct{}
 	offline             atomic.Bool
 	mu                  sync.Mutex
 	active              map[*websocket.Conn]struct{}
@@ -66,7 +69,7 @@ func newWorkerFaultGateway(t *testing.T, upstream string) *workerFaultGateway {
 
 func newProtocolFaultGateway(t *testing.T, upstream, path, protocol string) *workerFaultGateway {
 	t.Helper()
-	g := &workerFaultGateway{dropped: make(chan string, 4), active: make(map[*websocket.Conn]struct{})}
+	g := &workerFaultGateway{dropped: make(chan string, 4), active: make(map[*websocket.Conn]struct{}), assignmentsHeld: make(chan WorkerAssignment, 1), releaseAssignment: make(chan struct{})}
 	g.drop.Store("")
 	g.target.Store(upstream)
 	ctx, cancel := context.WithCancel(context.Background())
@@ -150,6 +153,20 @@ func newProtocolFaultGateway(t *testing.T, upstream, path, protocol string) *wor
 					g.dropped <- "task.cancel"
 					return
 				}
+				if f.Type == "task.assign" && g.holdAssignment.CompareAndSwap(true, false) {
+					var assignment WorkerAssignment
+					if json.Unmarshal(f.Body, &assignment) != nil {
+						return
+					}
+					// 真实派发帧只到隔离网关，不向Worker发送；测试确认节点退出后丢弃。
+					g.offline.Store(true)
+					g.assignmentsHeld <- assignment
+					select {
+					case <-g.releaseAssignment:
+					case <-bridge.Done():
+					}
+					return
+				}
 				if f.Type == "ack" && operation != "" && g.drop.CompareAndSwap(operation, "") {
 					if g.dropOffline.Load() {
 						g.offline.Store(true)