MCP Supabase dialog shows wrong project_ref despite correct .mcp.json

Bug

When configuring the Supabase MCP server via .mcp.json, the /mcp authentication dialog displays a stale/incorrect project reference in the URL, even though .mcp.json contains the correct project_ref.

Steps to reproduce

1. Set .mcp.json to point to a specific Supabase project:

``json
{
"mcpServers": {
"supabase": {
"url": "https://mcp.supabase.com/mcp?project_ref=<PROJECT_A>"
}
}
}
``

1. Run /mcp to authenticate.
2. The dialog displays a URL containing a different project ref (<PROJECT_B>) — not the one in .mcp.json.

Expected behavior

The authentication dialog should display the project_ref from the .mcp.json file on disk.

Actual behavior

The dialog shows a stale/cached project ref that doesn't match .mcp.json. This persists across:

• Editing and saving .mcp.json with the correct value
• Revoking old OAuth tokens on claude.ai
• Re-running /mcp multiple times

Workaround

Despite the wrong URL in the dialog, proceeding with authentication (option 1) actually connects to the correct project. Verified by running list_tables — the correct tables are returned. So the bug appears to be cosmetic/display-only, but it's confusing and erodes trust in the connection.

Environment

• macOS (Darwin 25.3.0)
• Claude Code CLI
• Supabase MCP server via remote URL