feat(lark): add Lark bot channel frontend

[0x0101010]

Summary / 概述

Adds a Lark (飞书) bot channel frontend to Reasonix, enabling users to interact with Reasonix through Lark chat — ask coding questions in a group or DM, get agent responses as progressive streaming messages, approve/deny tool calls via interactive card buttons.

为 Reasonix 添加 Lark（飞书）机器人通道前端，用户可以在飞书聊天中与 Reasonix 交互——群聊或私聊提问、流式查看 agent 回复、通过交互卡片审批工具调用。

Features / 功能

Lark Bot Frontend / 飞书机器人前端

• Multi-tenant session router: Per-chat conversation isolation with TTL expiry and concurrency limits
  多租户会话管理：按聊天隔离会话，支持 TTL 过期和并发限制
• Progressive streaming output: Model text streams live via ch.Stream(), with local buffer + async flush
  流式渐进输出：模型文本通过 ch.Stream() 实时流式输出，本地缓冲 + 异步刷新
• Interactive approval cards: ApprovalRequest → Lark card buttons → Controller.Approve()
  交互审批卡片：审批请求 → 飞书卡片按钮 → Controller.Approve()
• Clean output: Model text in streamed message, tool summary + token count in one markdown message
  干净输出：模型文本一条流式消息，工具摘要 + token 统计合并为一条 markdown 消息
• Config: [lark] section with env-first credential resolution (app_id_env / app_secret_env), matching Provider pattern
  配置：[lark] 段，支持 app_id_env/app_secret_env（与 Provider 的 api_key_env 模式一致）
• CLI: reasonix lark subcommand
  CLI：reasonix lark 子命令

Config Merge Fix / 配置保存修复

• SaveTo() uses toml.Marshal() for existing files instead of full RenderTOML() rewrite, preserving unrecognized TOML sections (e.g. [lark]) across saves
  SaveTo() 对已有文件使用 toml.Marshal() 而非全量覆写，确保新 section 不被丢弃
• First-run scaffolding still uses RenderTOML() for commented house style
  首次创建仍使用 RenderTOML() 生成带注释的脚手架配置

Files Changed / 文件变更

File / 文件	Change / 变更
internal/larkbot/ (new / 新增)	Session manager, event adapter, approval handler, bot main loop
internal/config/config.go	LarkConfig struct + accessor methods
internal/config/render.go	[lark] section in RenderTOML()
internal/config/edit.go	Merge-on-save via toml.Marshal()
internal/cli/cli.go + lark.go	reasonix lark subcommand
go.mod / go.sum	github.com/larksuite/oapi-sdk-go/v3 v3.9.4
reasonix.example.toml	Example [lark] config section

Dependencies / 依赖

• github.com/larksuite/oapi-sdk-go/v3 v3.9.4 (MIT)
  • Transitive: gorilla/websocket v1.5.0 (MIT), gogo/protobuf v1.3.2 (BSD)
  • All pure Go, no CGO, single-binary compatible
  • 全部纯 Go，无 CGO，兼容单二进制构建

Testing / 测试

• Config resolution: defaults, env var fallback, ${VAR} expansion
  配置解析：默认值、环境变量回退、${VAR} 展开
• Session router: creation, expiry, eviction, concurrency limits
  会话路由：创建、过期、驱逐、并发限制
• Merge-save: existing file preserves unrecognized section, new file uses RenderTOML()
  合并保存：已有文件保留未识别段，新文件使用脚手架
• Manual integration: end-to-end tested with live Lark app (message receive, streaming reply, approval card)
  手动集成：与真实飞书应用端到端测试

[wade19990814-hue]

v2版本应该是暂时不考虑IM通道的，核心定位是高缓存的编程工具而不是OpenClaw式的AI助手，另外目前可以通过cc-connect实现了https://github.com/chenhg5/cc-connect，建议还是关注其他issue解决比较好🙂