[BUG] Discord plugin MCP notifications not received on Windows/WSL (works on native Linux)

Description

The Discord
plugin MCP server correctly sends JSON-RPC notifications via stdout when a Discord message arrives, but Claude Code does
not process them on Windows or WSL. Works on native Linux (VPS Debian 13).

Steps to Reproduce

1. Install Discord

plugin

1. Configure bot token and access
2. Launch Claude

Code with --mcp-debug

1. Verify plugin MCP shows

connected

1. Send a DM to the bot

Expected: Claude
Code receives notification and responds
Actual: Bot shows
typing but Claude Code never receives the notification

##
Debug Evidence
Running MCP server standalone confirms
notifications ARE sent to stdout. MCP tools (fetch_messages,
reply) work. Only unsolicited push notifications are
ignored.

Environment

Claude Code 2.1.83, Plugin 0.0.1
and 0.0.4 tested, Bun 1.3.11

• Windows: tools work, push

notifications ignored

• WSL Ubuntu: tools work, push

notifications ignored

• VPS Debian 13: everything

works

Tested with two different bot tokens. VPS bot running
since March 22 without issues.
Related: #2722