feat(push-gateway): 修复WebSocket并发写竞争并添加DEV_MODE鉴权

hub.go 重写用send chan+单写协程模式避免并发写竞争

handler.go 加DEV_MODE dev-token支持+broadcast端点

config.go 加DevMode/RedisURL字段

services/push-gateway/internal/hub/hub.go

@@ -6,54 +6,94 @@ import (
 	"github.com/gorilla/websocket"
 )
 
-// Hub 管理 WebSocket 客户端连接
+// Connection 包装单个 WebSocket 连接及其异步发送通道
+type Connection struct {
+	UserID string
+	conn   *websocket.Conn
+	send   chan []byte
+}
+
+// Send 将消息投递到该连接的发送通道（非阻塞，通道满则丢弃）
+func (c *Connection) Send(message []byte) {
+	select {
+	case c.send <- message:
+	default:
+		// 通道满，丢弃消息避免阻塞 hub
+	}
+}
+
+// Outgoing 返回该连接的发送通道，供写协程消费
+func (c *Connection) Outgoing() <-chan []byte {
+	return c.send
+}
+
+// Hub 管理所有在线 WebSocket 连接，按 userID 索引
 type Hub struct {
 	mu      sync.RWMutex
-	clients map[string]map[*websocket.Conn]bool // userID -> connections
+	clients map[string]map[*Connection]bool
 }
 
+// NewHub 创建 Hub 实例
 func NewHub() *Hub {
 	return &Hub{
-		clients: make(map[string]map[*websocket.Conn]bool),
+		clients: make(map[string]map[*Connection]bool),
 	}
 }
 
-func (h *Hub) Register(userID string, conn *websocket.Conn) {
+// Register 注册一个用户连接，返回 Connection 供调用方持有
+func (h *Hub) Register(userID string, conn *websocket.Conn) *Connection {
+	c := &Connection{
+		UserID: userID,
+		conn:   conn,
+		send:   make(chan []byte, 64),
+	}
 	h.mu.Lock()
 	defer h.mu.Unlock()
-
 	if h.clients[userID] == nil {
-		h.clients[userID] = make(map[*websocket.Conn]bool)
+		h.clients[userID] = make(map[*Connection]bool)
 	}
-	h.clients[userID][conn] = true
+	h.clients[userID][c] = true
+	return c
 }
 
-func (h *Hub) Unregister(userID string, conn *websocket.Conn) {
+// Unregister 注销一个用户连接并关闭其发送通道
+func (h *Hub) Unregister(c *Connection) {
 	h.mu.Lock()
 	defer h.mu.Unlock()
-
-	if conns, ok := h.clients[userID]; ok {
-		delete(conns, conn)
-		if len(conns) == 0 {
-			delete(h.clients, userID)
-		}
+	conns, ok := h.clients[c.UserID]
+	if !ok {
+		return
+	}
+	if _, exists := conns[c]; exists {
+		delete(conns, c)
+		close(c.send)
+	}
+	if len(conns) == 0 {
+		delete(h.clients, c.UserID)
 	}
 }
 
-// SendToUser 向指定用户的所有连接推送消息
+// SendToUser 向指定用户的所有在线连接推送消息
 func (h *Hub) SendToUser(userID string, message []byte) error {
 	h.mu.RLock()
 	defer h.mu.RUnlock()
-
 	conns, ok := h.clients[userID]
 	if !ok {
 		return nil
 	}
-
-	for conn := range conns {
-		if err := conn.WriteMessage(websocket.TextMessage, message); err != nil {
-			return err
-		}
+	for c := range conns {
+		c.Send(message)
 	}
 	return nil
 }
+
+// Broadcast 向所有在线连接广播消息
+func (h *Hub) Broadcast(message []byte) {
+	h.mu.RLock()
+	defer h.mu.RUnlock()
+	for _, conns := range h.clients {
+		for c := range conns {
+			c.Send(message)
+		}
+	}
+}