MCP server unavailable is reported as "waiting on ide" and hangs copilot-cli

Describe the bug

If you have an entry like this in your ~/.copilot/mcp-config.json

    "dummy": {
      "tools": [
        "*"
      ],
      "type": "http",
      "url": "http://bextop17:4000/mcp",
      "headers": {
        "Authorization": "Bearer token"
      }
    }

And the host is unavailable (it is in DNS but the system as a whole is unreachable) then copilot will hang on startup eventually showing the message "waiting on ide." IDE is not in use.

Important: using a non-existent dns name will NOT recreate this error. The host must be defined in DNS and not available. Using an existing host with a down service (system up, but port not) will NOT recreate this. My tests were confirmed by unplugging a system next to me's ethernet cable.

Affected version

GitHub Copilot CLI 1.0.81-6

Steps to reproduce the behavior

1. Define an mcp server for a system that has a valid dns name but is not on the network
2. start copilot cli
3. see error

Expected behavior

The cli should report the correct error message and not hang on a missing mcp server.

Additional context

This is on MacOS 15.7.7 (24G720) connecting to an mcp server on my local network which I had unplugged from the network for $reasons. This left the name in DNS but the system unavailable.

Commencez par le chemin de démarrage de la CLI qui se connecte aux serveurs MCP configurés, puis reproduisez le problème avec un hôte résolvable par DNS mais inaccessible sur le réseau. C'est terminé lorsque la CLI signale correctement l'échec de la connexion MCP et continue sans se bloquer ni afficher incorrectement "waiting on ide.".