docs(channels): add design documentation for channels feature

- Architecture overview with platform adapters and ACP bridge
- Plugin system contract and extension loading
- Implementation guides for Telegram, WeChat, DingTalk
- Testing guide with mock servers and E2E scenarios
- Feature roadmap and known limitations

These docs provide the foundation for the external messaging integrations.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

docs/design/channels/channels-roadmap.md

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+# Channels Roadmap
+
+## Implemented (MVP)
+
+- **3 built-in channels** — Telegram, WeChat, DingTalk
+- **Plugin system** — `ChannelBase` SDK with `connect`/`sendMessage`/`disconnect`, extension manifest, compiled JS + `.d.ts`
+- **Access control** — `allowlist`, `pairing` (8-char codes, CLI approval), `open` policies
+- **Group chat** — `open`/`disabled`/`allowlist` group policy, `requireMention` per group, reply-as-mention
+- **Session routing** — `user`, `thread`, `single` scopes with per-channel `cwd`, `model`, `instructions`
+- **Dispatch modes** — `steer` (default: cancel + re-prompt), `collect` (buffer + coalesce), `followup` (sequential queue). Per-channel and per-group config.
+- **Working indicators** — centralized `onPromptStart`/`onPromptEnd` hooks. Telegram: typing bar. WeChat: typing API. DingTalk: 👀 emoji reaction.
+- **Block streaming** — progressive multi-message delivery with paragraph-aware chunking
+- **Streaming hooks** — `onResponseChunk`/`onResponseComplete` for plugins to implement progressive display
+- **Media support** — images (vision input), files/audio/video (saved to temp, path in prompt), `Attachment` interface on `Envelope`
+- **Slash commands** — `/help`, `/clear` (`/reset`, `/new`), `/status`, custom via `registerCommand()`
+- **Service management** — `qwen channel start/stop/status`, PID tracking, crash recovery (auto-restart, session persistence)
+- **Token security** — `$ENV_VAR` syntax in config
+
+## Future Work
+
+### Safety & Group Chat
+
+- **Per-group tool restrictions** — `tools`/`toolsBySender` deny/allow lists per group
+- **Group context history** — ring buffer of recent skipped messages, prepended on @mention
+- **Regex mention patterns** — fallback `mentionPatterns` for unreliable @mention metadata
+- **Per-group instructions** — `instructions` field on `GroupConfig` for per-group personas
+- **`/activation` command** — runtime toggle for `requireMention`, persisted to disk
+
+### Operational Tooling
+
+- **`qwen channel doctor`** — config validation, env vars, bot tokens, network checks
+- **`qwen channel status --probe`** — real connectivity checks per channel
+
+### Platform Expansion
+
+- **Discord** — Bot API + Gateway, servers/channels/DMs/threads
+- **Slack** — Bolt SDK, Socket Mode, workspaces/channels/DMs/threads
+
+### Multi-Agent
+
+- **Multi-agent routing** — multiple agents with bindings per channel/group/user
+- **Broadcast groups** — multiple agents respond to the same message
+
+### Plugin Ecosystem
+
+- **Community plugin template** — `create-qwen-channel` scaffolding tool
+- **Plugin registry/discovery** — `qwen extensions search`, version compatibility
+
+## Reference: OpenClaw Comparison
+
+See [channels-comparison.md](channels-comparison.md) for the detailed feature comparison between OpenClaw and Qwen-Code channels.