fix: 完成 broker 复审 B-03 至 B-12

每连接异步下发与背压、写出后断开、校验当前连接与订阅、生命周期串行、登录条件更新、闲置按在线计、认证超时并发与 Shutdown 0x8B。

internal/broker/hooks.go

@@ -30,6 +30,7 @@ func (h *nixHook) Provides(b byte) bool {
 		mqtt.OnQosComplete,
 		mqtt.OnQosDropped,
 		mqtt.OnSubscribed,
+		mqtt.OnPacketSent,
 	}, []byte{b})
 }
 
@@ -79,7 +80,9 @@ func (h *nixHook) OnConnect(cl *mqtt.Client, pk packets.Packet) error {
 			"endpoint", endpointID, "receive_maximum", rm)
 	}
 
-	res, err := h.b.auth.Authenticate(context.Background(), endpointID, pk.Connect.Password, remoteIP)
+	authCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	res, err := h.b.auth.Authenticate(authCtx, endpointID, pk.Connect.Password, remoteIP)
 	if err != nil {
 		return err // mochi 不回 CONNACK，直接断开；不登记连接表
 	}
@@ -171,6 +174,18 @@ func (h *nixHook) OnSubscribed(cl *mqtt.Client, pk packets.Packet, reasonCodes [
 	}
 }
 
+func (h *nixHook) OnPacketSent(cl *mqtt.Client, pk packets.Packet, _ []byte) {
+	if pk.FixedHeader.Type != packets.Publish {
+		return
+	}
+	h.b.connsMu.RLock()
+	st := h.b.byClient[cl]
+	h.b.connsMu.RUnlock()
+	if st != nil {
+		st.sentPub.Add(1)
+	}
+}
+
 func (h *nixHook) OnPublishDropped(cl *mqtt.Client, pk packets.Packet) {
 	h.b.log.Debug("publish dropped", "client", cl.ID, "topic", pk.TopicName, "size", len(pk.Payload))
 	h.b.connsMu.RLock()
@@ -188,7 +203,9 @@ func (h *nixHook) OnPublishDropped(cl *mqtt.Client, pk packets.Packet) {
 func (h *nixHook) OnSessionEstablished(cl *mqtt.Client, _ packets.Packet) {
 	h.b.connsMu.Lock()
 	st := h.b.byClient[cl]
+	var old *connState
 	if st != nil {
+		old = h.b.current[st.endpointID]
 		h.b.current[st.endpointID] = st
 		st.established = true
 	}
@@ -196,6 +213,15 @@ func (h *nixHook) OnSessionEstablished(cl *mqtt.Client, _ packets.Packet) {
 	if st == nil {
 		return
 	}
+	lk := h.b.endpointLife(st.endpointID)
+	lk.Lock()
+	if old != nil && old != st {
+		old.mu.Lock()
+		old.superseded = true
+		old.mu.Unlock()
+	}
+	lk.Unlock()
+	st.startDownLoop(h.b)
 	info := port.ConnInfo{
 		ConnID:        st.connID,
 		EndpointID:    st.endpointID,
@@ -224,6 +250,10 @@ func (h *nixHook) OnDisconnect(cl *mqtt.Client, err error, _ bool) {
 	if st == nil {
 		return
 	}
+	lk := h.b.endpointLife(st.endpointID)
+	lk.Lock()
+	st.stopDownLoop()
+	lk.Unlock()
 	h.b.releaseAllLarge(st)
 	h.b.cancelHandshakeDeadline(st.endpointID, st.connID)