Discord channel plugin: inbound notifications not delivered to conversation

Description

The Discord channel plugin's MCP server connects successfully and all tools (reply, fetch_messages, react, edit_message) work correctly. However, inbound Discord messages never appear in the Claude Code conversation.

Steps to reproduce

1. Configure Discord plugin with bot token in ~/.claude/channels/discord/.env
2. Pair a Discord user via /discord:access
3. DM the bot on Discord
4. Bot shows typing indicator (confirms messageCreate fires and gate() allows delivery)
5. mcp.notification({ method: 'notifications/claude/channel' }) fires — but no <channel source="discord" ...> block appears in the conversation

Expected behavior

Inbound Discord messages should appear in the conversation as <channel source="discord" ...> blocks, prompting Claude to reply.

Actual behavior

Nothing appears in the conversation. The bot receives the message (typing indicator shows), but the MCP notification is silently dropped. Claude never sees the inbound message and can't reply.

Tools work fine when called manually — fetch_messages returns the DM history and reply sends messages back to Discord successfully.

Troubleshooting attempted

• /reload-plugins — no effect
• Fresh Claude Code session — no effect
• Verified bot token, access policy (allowFrom includes the sender), and plugin is enabled in settings.json

Environment

• Claude Code v2.1.80
• Discord plugin v0.0.1
• macOS (Darwin 24.3.0)
• Bun runtime