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/model/conversation.go

@@ -1,12 +1,9 @@
 package model
 
 import (
-	"strconv"
 	"time"
 
 	"gorm.io/gorm"
-
-	"with_you/internal/pkg/utils"
 )
 
 // ConversationType 会话类型
@@ -36,14 +33,7 @@ type Conversation struct {
 
 // BeforeCreate 创建前生成雪花算法ID
 func (c *Conversation) BeforeCreate(tx *gorm.DB) error {
-	if c.ID == "" {
-		id, err := utils.GetSnowflake().GenerateID()
-		if err != nil {
-			return err
-		}
-		c.ID = strconv.FormatInt(id, 10)
-	}
-	return nil
+	return SetSnowflakeStringID(&c.ID)
 }
 
 func (Conversation) TableName() string {