refactor: improve system stability, performance, and code structure

This commit introduces several architectural improvements and optimizations across the codebase:

- **Performance & Reliability**:
  - Implemented Redis pipelining in `ConversationCache.CacheMessage` to reduce network round-trips.
  - Added a circuit breaker to the JPush client to prevent cascading failures.
  - Introduced batch deletion and batch member addition capabilities in repositories.
  - Added message idempotency support using `client_msg_id` and a Redis-based cache.
  - Optimized WebSocket handling with connection limits (total and per-user) and improved error logging.

- **Code Refactoring**:
  - Refactored `Router` to use a `RouterDeps` struct, simplifying the constructor and improving maintainability.
  - Unified model ID generation logic using new `id_helper.go` (supporting UUID and Snowflake).
  - Standardized JSON serialization/deserialization in models using `json_helper.go`.
  - Refactored DTO conversion logic, specifically for `UserResponse` (using functional options) and `Report` responses.
  - Removed redundant/deprecated DTOs like `PostDetailResponse` and `TradeItemDetailResponse`.

- **Cache Improvements**:
  - Enhanced `LayeredCache` with `SetRaw` to avoid double-encoding when promoting values from Redis to local cache.
  - Added `DeleteBatch` support to the cache interface.

- **Other Changes**:
  - Cleaned up `config.go` by removing redundant default values and explicit environment variable overrides.
  - Improved WebSocket registration flow to handle connection limits gracefully.

internal/handler/message_handler.go

@@ -316,8 +316,7 @@ func (h *MessageHandler) SendMessage(c *gin.Context) {
 		return
 	}
 
-	// 直接使用 segments
-	msg, err := h.chatService.SendMessage(c.Request.Context(), userID, conversationID, req.Segments, req.ReplyToID)
+	msg, err := h.chatService.SendMessage(c.Request.Context(), userID, conversationID, req.Segments, req.ReplyToID, req.ClientMsgID)
 	if err != nil {
 		response.BadRequest(c, err.Error())
 		return
@@ -359,7 +358,7 @@ func (h *MessageHandler) HandleSendMessage(c *gin.Context) {
 	}
 
 	// 发送消息
-	msg, err := h.chatService.SendMessage(c.Request.Context(), userID, conversationID, params.Segments, params.ReplyToID)
+	msg, err := h.chatService.SendMessage(c.Request.Context(), userID, conversationID, params.Segments, params.ReplyToID, params.ClientMsgID)
 	if err != nil {
 		response.BadRequest(c, err.Error())
 		return