feat(chat): implement sequence pre-allocation, versioned sync, and push worker

Introduce several performance and synchronization enhancements:
- Implement `SeqBufferManager` to allow sequence number pre-allocation via Redis Lua scripts, reducing atomic increment overhead.
- Add `PushWorker` to handle asynchronous message pushing using Redis Streams.
- Implement incremental conversation synchronization via `ConversationVersionLog` to allow clients to fetch only recent changes.
- Add support for Gzip compression in WebSocket communications to reduce bandwidth usage.
- Update dependency injection and configuration to support these new components.

internal/cache/keys.go

@@ -44,6 +44,7 @@ const (
 	keyPrefixMsgSeq      = "msg_seq"    // Seq 计数器
 	keyPrefixMsgPage     = "msg_page"   // 分页缓存
 	keyPrefixMsgIdempotent = "msg_idem"  // 消息幂等键
+	keyPrefixSeqBuffer   = "seq_buf"    // Seq 预分配缓冲区 Hash
 )
 
 // PostListKey 生成帖子列表缓存键
@@ -197,6 +198,11 @@ func MessageIdempotentKey(senderID, clientMsgID string) string {
 	return fmt.Sprintf("%s:%s:%s", keyPrefixMsgIdempotent, senderID, clientMsgID)
 }
 
+// SeqBufferKey seq 预分配缓冲区 Hash key
+func SeqBufferKey(convID string) string {
+	return fmt.Sprintf("%s:%s", keyPrefixSeqBuffer, convID)
+}
+
 
 // UserReadSeqKey 用户已读位置缓存键（OpenIM 风格 SEQ_USER_READ:{convID}:{userID}）
 func UserReadSeqKey(convID, userID string) string {