Telegram plugin: inbound message delivery broken (outbound works)

Bug Report

Description

The Telegram plugin (telegram@claude-plugins-official v0.0.1) can send messages (reply, react, edit_message tools all work), but inbound messages from Telegram are never delivered to the Claude Code session. The MCP notifications/claude/channel notification appears to not reach the client.

Environment

• macOS (Apple Silicon), Darwin 25.3.0
• Claude Code with --channels plugin:telegram@claude-plugins-official
• Bun runtime
• Plugin MCP server status shows "running" in /plugin

Steps to Reproduce

1. Install plugin: /plugin install telegram@claude-plugins-official
2. Configure with bot token via /telegram:configure
3. Launch: claude --channels plugin:telegram@claude-plugins-official
4. Pair a user or add to allowFrom in access.json
5. Send a DM or group message to the bot
6. Message never appears in the Claude Code session

What Works

• Outbound reply tool sends messages successfully
• Outbound react and edit_message tools work
• Bot token is valid (getMe returns correctly)
• Bot is polling (getUpdates returns empty, confirming updates are consumed)
• Plugin MCP server shows as "running"

What Doesn't Work

• No inbound messages are delivered to the session (DM or group)
• Tested with both requireMention: true and false
• Tested with privacy mode enabled and disabled via BotFather
• Confirmed can_read_all_group_messages: true after disabling privacy mode
• Multiple session restarts and /reload-plugins did not fix it

access.json (sanitized)

{
  "dmPolicy": "allowlist",
  "allowFrom": ["<user_id>"],
  "groups": {
    "<group_id>": {
      "requireMention": false,
      "allowFrom": []
    }
  },
  "pending": {}
}

Suspected Cause

The bot's handleInbound() function calls mcp.notification() with method notifications/claude/channel, but this notification never reaches the Claude Code client. The MCP stdio transport between the bot process and Claude Code may not be forwarding notifications correctly.