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/config/version_log.go

@@ -0,0 +1,8 @@
+package config
+
+// VersionLogConfig 版本日志增量同步配置
+type VersionLogConfig struct {
+	Enabled     bool `mapstructure:"enabled"`
+	SyncLimit   int  `mapstructure:"sync_limit"`    // 单次同步最大返回条数
+	MaxSyncGap  int64 `mapstructure:"max_sync_gap"` // 超过此版本差距建议全量同步
+}