Telegram channel plugin: notifications/claude/channel not delivered to conversation

Summary

The Telegram channel plugin (telegram@claude-plugins-official) sends MCP notifications via notifications/claude/channel, but they never surface in the conversation. The bot receives messages and processes them correctly — the issue is on the client side.

Steps to reproduce

1. Configure the Telegram plugin with a valid bot token (/telegram:configure <token>)
2. Set access policy to allowlist with a valid Telegram user ID (/telegram:access)
3. Send a DM to the bot on Telegram

Expected behavior

The message appears in the Claude Code conversation as a <channel source="telegram" ...> block, and the assistant can reply via the telegram__reply tool.

Actual behavior

• The bot receives the message (typing indicator appears in Telegram)
• The MCP notification is sent by the server (line 580 of server.ts: mcp.notification({ method: 'notifications/claude/channel', ... }))
• Nothing arrives in the conversation
• No error output visible

Debugging done

• Confirmed the bot process is running (ps aux)
• Confirmed the MCP tool connection works (tool schemas load, reply tool is callable)
• Confirmed the user is on the allowlist and the gate returns deliver
• Reloaded plugins (/reload-plugins), restarted the session — no change
• The server declares experimental: { 'claude/channel': {} } in its capabilities

Environment

• Claude Code: 2.1.80 (Homebrew)
• Bun: 1.3.11
• MCP SDK: 1.27.1
• macOS (Darwin 25.3.0)

Hypothesis

The client does not yet handle the notifications/claude/channel experimental MCP notification method, so the notification is silently dropped despite the server sending it correctly.