feat: add automatic Worker runtime with lease recovery and bounded shutdown

sdk/go/worker_integration_test.go

@@ -49,17 +49,24 @@ func integrationWorkerClient(t *testing.T) (*Client, string, string) {
 // 只丢响应，不伪造任务状态，测试凭据不进入 URL 或输出。
 type workerFaultGateway struct {
 	drop    atomic.Value
+	offline atomic.Bool
+	mu      sync.Mutex
+	active  map[*websocket.Conn]struct{}
 	dropped chan string
 	server  *httptest.Server
 }
 
 func newWorkerFaultGateway(t *testing.T, upstream string) *workerFaultGateway {
 	t.Helper()
-	g := &workerFaultGateway{dropped: make(chan string, 4)}
+	g := &workerFaultGateway{dropped: make(chan string, 4), active: make(map[*websocket.Conn]struct{})}
 	g.drop.Store("")
 	ctx, cancel := context.WithCancel(context.Background())
 	var handlers sync.WaitGroup
 	g.server = httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if g.offline.Load() {
+			http.Error(w, "gateway offline", 503)
+			return
+		}
 		handlers.Add(1)
 		defer handlers.Done()
 		bridge, stop := context.WithCancel(ctx)
@@ -78,6 +85,13 @@ func newWorkerFaultGateway(t *testing.T, upstream string) *workerFaultGateway {
 			return
 		}
 		defer down.CloseNow()
+		g.mu.Lock()
+		g.active[down] = struct{}{}
+		g.mu.Unlock()
+		defer func() { g.mu.Lock(); delete(g.active, down); g.mu.Unlock() }()
+		if g.offline.Load() {
+			return
+		}
 		down.SetReadLimit(512 << 10)
 		var mu sync.Mutex
 		var forwarding sync.WaitGroup
@@ -141,6 +155,17 @@ func newWorkerFaultGateway(t *testing.T, upstream string) *workerFaultGateway {
 	t.Cleanup(func() { cancel(); g.server.Close(); handlers.Wait() })
 	return g
 }
+func (g *workerFaultGateway) disconnectActive() {
+	g.mu.Lock()
+	active := make([]*websocket.Conn, 0, len(g.active))
+	for c := range g.active {
+		active = append(active, c)
+	}
+	g.mu.Unlock()
+	for _, c := range active {
+		c.CloseNow()
+	}
+}
 func (g *workerFaultGateway) expectDrop(t *testing.T, operation string) {
 	t.Helper()
 	select {