OpenTelemetry and Langfuse observability exporter for DeepSeek Harness: turn/step/tool/LLM spans, token and cost metrics, and sanitized LLM prompt/completion capture from the session/event stream, with async batching, bounded offline buffering, and retry

DeepSeek Harness 桌宠：元气鲸鱼娘，45 项成就、3 个小游戏、跨端存档迁移；按工具类型切换工作姿态，桌面端与旧版 Web 双端支持（desktop pet / mascot，local-first）