feat(ws): implement WebSocket cluster mode with Redis Pub/Sub

Introduce a new WebSocket messaging architecture that supports both standalone and cluster modes. This allows for horizontal scaling of WebSocket servers by using Redis Pub/Sub to synchronize messages across multiple instances.

Key changes:
- Added `ws.MessagePublisher` interface to abstract message distribution.
- Implemented `ws.Bus` to handle cluster-mode messaging via Redis.
- Added `ws.OnlineTracker` to manage user online status across the cluster.
- Refactored multiple services (Chat, Group, Push, Call, etc.) to use the new `MessagePublisher` instead of a concrete `ws.Hub`.
- Added WebSocket configuration options (mode, instance ID, channel, TTL, heartbeat) to `config.yaml` and `config.go`.
- Updated dependency injection with Wire to support the new publisher and Redis client.
- Improved logging by replacing standard `log` with `zap` in several service components.

internal/pkg/ws/publisher.go

@@ -0,0 +1,23 @@
+package ws
+
+// MessagePublisher 定义消息发布接口
+// ws.Hub 隐式满足此接口，ws.Bus 组合 Hub 并扩展跨实例能力
+type MessagePublisher interface {
+	// 消息发布
+	PublishToUser(userID string, eventType string, payload any) Event
+	PublishToUsers(userIDs []string, eventType string, payload any)
+	PublishToUsersConcurrent(userIDs []string, eventType string, payload any)
+	PublishToUserOnline(userID string, eventType string, payload any) bool
+	PublishToUserOnlineReliable(userID string, eventType string, payload any) bool
+	Broadcast(eventType string, payload any)
+
+	// 在线状态
+	HasClients(userID string) bool
+	FilterOnline(userIDs []string) (online, offline []string)
+
+	// 本地操作（不经过 Redis）
+	SendError(client *Client, code string, message string)
+	NextID() uint64
+	OnDisconnect(handler DisconnectHandler)
+	OnConnect(handler ConnectHandler)
+}