feat(home): add cluster nodes payload parsing and Redis channel handling

- Added `parseClusterNodesPayload` for streamlined cluster node parsing.
- Introduced `handleSubscriptionPayload` to handle Redis channel payloads, including updates for the new `cluster` channel.
- Updated subscription logic to process and apply cluster node updates seamlessly.

internal/home/client.go

@@ -31,6 +31,7 @@ const (
 
 	homeReconnectInterval          = time.Second
 	homeReconnectFailoverThreshold = 3
+	redisChannelCluster            = "cluster"
 )
 
 var (
@@ -310,11 +311,10 @@ func (c *Client) refreshClusterNodes(ctx context.Context) (bool, error) {
 		return false, errDo
 	}
 
-	var envelope clusterNodesEnvelope
-	if errUnmarshal := json.Unmarshal([]byte(raw), &envelope); errUnmarshal != nil {
-		return false, errUnmarshal
+	nodes, errParse := parseClusterNodesPayload([]byte(raw))
+	if errParse != nil {
+		return false, errParse
 	}
-	nodes := normalizeClusterNodes(envelope.Nodes)
 	if len(nodes) == 0 {
 		return false, nil
 	}
@@ -326,6 +326,28 @@ func (c *Client) refreshClusterNodes(ctx context.Context) (bool, error) {
 	return c.switchToNodeLocked(nodes[0]), nil
 }
 
+func parseClusterNodesPayload(raw []byte) ([]clusterNode, error) {
+	var envelope clusterNodesEnvelope
+	if errUnmarshal := json.Unmarshal(raw, &envelope); errUnmarshal != nil {
+		return nil, errUnmarshal
+	}
+	return normalizeClusterNodes(envelope.Nodes), nil
+}
+
+func (c *Client) updateClusterNodesFromPayload(raw []byte) error {
+	if c == nil || !c.clusterDiscoveryEnabled() {
+		return nil
+	}
+	nodes, errParse := parseClusterNodesPayload(raw)
+	if errParse != nil {
+		return errParse
+	}
+	c.mu.Lock()
+	c.clusterNodes = nodes
+	c.mu.Unlock()
+	return nil
+}
+
 func normalizeClusterNodes(nodes []clusterNode) []clusterNode {
 	out := make([]clusterNode, 0, len(nodes))
 	for _, node := range nodes {
@@ -570,6 +592,25 @@ func (c *Client) RPushRequestLog(ctx context.Context, payload []byte) error {
 	return cmd.RPush(ctx, redisKeyRequestLog, payload).Err()
 }
 
+func (c *Client) handleSubscriptionPayload(channel string, payload string, onConfig func([]byte) error) error {
+	payload = strings.TrimSpace(payload)
+	if payload == "" {
+		return nil
+	}
+
+	switch strings.ToLower(strings.TrimSpace(channel)) {
+	case redisChannelConfig:
+		if onConfig == nil {
+			return nil
+		}
+		return onConfig([]byte(payload))
+	case redisChannelCluster:
+		return c.updateClusterNodesFromPayload([]byte(payload))
+	default:
+		return nil
+	}
+}
+
 // StartConfigSubscriber connects to home, fetches config once via GET config, then subscribes to
 // the "config" channel to receive runtime config updates.
 //
@@ -664,8 +705,10 @@ func (c *Client) StartConfigSubscriber(ctx context.Context, onConfig func([]byte
 			if msg == nil {
 				continue
 			}
-			if payload := strings.TrimSpace(msg.Payload); payload != "" {
-				if errApply := onConfig([]byte(payload)); errApply != nil {
+			if errApply := c.handleSubscriptionPayload(msg.Channel, msg.Payload, onConfig); errApply != nil {
+				if strings.EqualFold(strings.TrimSpace(msg.Channel), redisChannelCluster) {
+					log.Warn("failed to apply cluster update from home control center, ignoring")
+				} else {
 					log.Warn("failed to apply config update from home control center, ignoring")
 				}
 			}