Telegram plugin: channel notifications not delivered to session

Description

The Telegram plugin (telegram@claude-plugins-official) receives messages and processes them correctly, but notifications/claude/channel never reaches the Claude Code session. Outbound (reply/react/edit) works fine — only inbound delivery is broken.

Environment

• Claude Code: 2.1.92
• OS: macOS (Darwin 25.4.0, Apple Silicon)
• Plugin runtime: Bun
• Plugin: telegram@claude-plugins-official (enabled in settings.json)

Diagnosis

| Check | Result |
|-------|--------|
| Bot token valid | ✅ getMe returns bot info |
| Plugin process running | ✅ PID active, TCP connections to 149.154.166.110 (Telegram API) |
| Polling active | ✅ Long-poll connections established |
| access.json correct | ✅ sender ID in allowFrom |
| gate() passes | ✅ confirmed via ackReaction — 👀 emoji appears on sender's message |
| MCP outbound tools (reply/react) | ✅ work correctly |
| notifications/claude/channel delivery | ❌ never received by session |

Steps to reproduce

1. Install and enable the Telegram plugin
2. Configure bot token and pair a user (user appears in allowFrom)
3. Set ackReaction in access.json to verify plugin receives messages
4. Send a message from Telegram to the bot
5. Observe: ack reaction appears (plugin processed the message), but Claude Code session receives no channel notification

Expected behavior

Messages should appear in the Claude Code session as <channel source="telegram" ...> blocks.

Actual behavior

Plugin receives and processes inbound messages (confirmed by ackReaction), calls mcp.notification({ method: 'notifications/claude/channel', ... }), but the notification is silently dropped — nothing appears in the session. The .catch() handler on the notification call does not fire (no stderr output), suggesting the MCP write succeeds but the client side ignores it.