HTTP MCP server that requires OAuth freezes entire CLI

Bug

When an HTTP-based MCP server (e.g. https://mcp.linear.app/mcp) is enabled but hasn't completed OAuth authentication, the entire Claude Code CLI freezes. This happens when:

1. Typing /mcp to list MCP servers
2. Starting a new session (Claude Code attempts to connect to all enabled servers on startup)

The CLI becomes completely unresponsive — no timeout, no error message, no way to recover except killing the process.

Expected behavior

• HTTP MCP connections should have a reasonable timeout (e.g. 5s)
• If an MCP server fails to connect or requires auth, it should be marked as unavailable with an error message, not block the entire CLI
• Other MCP servers and core CLI functionality should continue working even when one server is unresponsive

Reproduction

1. Enable an HTTP MCP server that requires OAuth: claude mcp add linear-server --type http --url https://mcp.linear.app/mcp
2. Don't complete the OAuth flow
3. Type /mcp — CLI freezes indefinitely

Workaround

claude mcp disable linear-server (but you have to do this from a separate terminal since the CLI is frozen)

Environment

• macOS Darwin 25.4.0
• Claude Code CLI (latest)