/mcp hangs when authorizing a plugin-provided connector (Stripe)

Attempting to authorize the Stripe plugin connector (plugin:stripe:stripe) via /mcp in an interactive session hangs / doesn't complete. Connector status remains needs_auth even after the user reports completing authorization elsewhere (checked via session status — reconnect correctly reports it needs a user-driven sign-in, but the /mcp flow itself did not complete for the user).

Reproduced in the Claude Code desktop app (Code tab).

Steps to reproduce:

1. Have a plugin-provided MCP server (e.g. the Stripe plugin) in needs_auth state.
2. Run /mcp in an interactive session to authorize it.
3. The authorization flow hangs / does not complete.