Telegram plugin: inbound notifications/claude/channel not delivered to session (v2.1.89, macOS)

Bug Description

Telegram plugin's inbound MCP channel notifications (notifications/claude/channel) are not delivered to the Claude Code session. The bot receives messages and processes them successfully, but they never appear in the conversation.

Environment

• Claude Code version: 2.1.89
• OS: macOS (Darwin 25.4.0, arm64)
• Runtime: Bun
• Plugin: claude-plugins-official/telegram v0.0.4
• MCP SDK: @modelcontextprotocol/sdk ^1.0.0

What works

• Bot polls Telegram successfully (confirmed via 409 Conflict on manual getUpdates)
• gate() passes — typing indicator shows in Telegram
• mcp.notification() resolves successfully (no error)
• Outbound reply tool works perfectly — bot sends messages to Telegram without issue
• MCP stdio transport is functional for tool calls (request/response)

What doesn't work

• Inbound messages from Telegram never appear in the Claude Code conversation
• mcp.notification({ method: 'notifications/claude/channel', ... }) completes with no error but the client does not surface the message

Debug evidence

Added file-based debug logging to server.ts. After sending a message from Telegram:

[2026-04-01T05:21:52.783Z] handleInbound: gate passed, chat_id=7207774160, user=7207774160, text=333
[2026-04-01T05:21:52.783Z] mcp.notification called: {"method":"notifications/claude/channel","params":{"content":"333","meta":{"chat_id":"7207774160","message_id":"48","user":"7207774160","user_id":"7207774160","ts":"2026-04-01T05:21:52.000Z"}}}
[2026-04-01T05:21:52.784Z] mcp.notification SUCCESS

The server-side notification succeeds, but the Claude Code client silently drops it.

Steps to reproduce

1. Configure Telegram plugin with bot token and allowlist
2. Start Claude Code session
3. Send a message to the bot from Telegram
4. Observe: typing indicator appears in Telegram, but message never arrives in Claude Code
5. Use the reply tool to send a message back — this works fine

What I've tried

• Restarting Claude Code multiple times
• Killing orphaned bot processes and restarting
• /reload-plugins
• claude --update (already latest)
• Verified access.json has correct allowFrom with sender's user ID

Related issues

• #36429, #36431, #36472, #36802, #37498, #37633, #37933, #38259