[Windows] --dangerously-load-development-channels does not enable inbound channel notifications

Summary

--dangerously-load-development-channels reliably enables inbound channel notifications on macOS but silently fails on Windows. The MCP server connects, outbound tools work, but notifications/claude/channel is never delivered to the conversation.

Environment

• OS: Windows 11 Home (10.0.26200)
• Shell: Git Bash (also tested concept in PowerShell)
• Claude Code: 2.1.97
• Auth: claudeAiOauth, Max plan, default_claude_max_5x rate-limit tier
• Plugin: telegram@claude-plugins-official v0.0.4
• MCP server name: telegram (matching server:telegram in flag)

Steps to reproduce

1. Configure Telegram MCP server in .mcp.json with name telegram
2. Run:

``bash
claude --dangerously-load-development-channels server:telegram --debug
``

1. Verify MCP server connects (/mcp → telegram · ✔ connected)
2. Send a message to the bot from Telegram

Expected behavior

Inbound message is delivered to the Claude conversation via notifications/claude/channel.

Actual behavior

• ✅ MCP server connects successfully
• ✅ Outbound reply tool sends messages to Telegram
• ✅ Bot shows "typing..." in Telegram (MCP server receives the inbound message)
• ❌ notifications/claude/channel never reaches the conversation
• ❌ Claude session shows no indication of an incoming message

The bot receiving the message and showing "typing..." confirms the MCP server processes the inbound message and sends the notification — but Claude Code drops it silently.

What I've tested

| # | What | Result |
|---|------|--------|
| 1 | --channels plugin:telegram@claude-plugins-official | --channels ignored |
| 2 | --dangerously-load-development-channels server:telegram | No error, but inbound silent |
| 3 | --dangerously-load-development-channels plugin:telegram@... | No effect |
| 4 | Plugin versions 0.0.1 → 0.0.4 | No difference |
| 5 | Claude Code versions 2.1.81 → 2.1.97 | No difference |
| 6 | Disabled official plugin to avoid duplicate MCP conflict | Same result |

Cross-platform comparison

• macOS: --dangerously-load-development-channels bypasses tengu_harbor feature flag — confirmed working by multiple users on 2.1.92–2.1.96
• Windows: Same flag with same auth level does not enable inbound notifications

Hypothesis

Windows stdio handling differs from macOS/Linux (line ending conversion, buffering behavior), which may affect how JSON-RPC notifications are delivered over the MCP subprocess pipe. The notification is sent by the MCP server but never processed by Claude Code on Windows.

Related issues

• #36503 — Main channels/tengu_harbor discussion (this issue was filed at the request of community members there)
• #36460 — tengu_harbor feature flag deep-dive
• #36964 — MCP server dies on Windows (another Windows-specific channel issue)