[BUG] Desktop: HTTP MCP server in a marketplace plugin's `.mcp.json` is counted but never registered as a connector

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

A custom marketplace plugin (installed in the Desktop app from a GitHub-repo marketplace) bundles a remote MCP server via .mcp.json using type: "http" (a Cloud Run endpoint behind OAuth). Desktop parses the manifest — the plugin detail page shows "It provides 1 connector" — but the connector never appears in Customize → Connectors, the OAuth flow is never initiated, and the server's tools are never available in any session. The plugin is enabled and up to date.

In earlier Desktop versions the bundled connector was listed inline in the plugin detail view and was connectable from there. In the current version the plugin detail only enumerates Skills/Agents and collapses connectors to an opaque count, and the HTTP connector no longer surfaces in Connectors at all — so there is no path to connect or authorize it from the plugin.

This appears to be the "never surfaces" variant of #47819 (which reports a Server not found error on explicit Connect). Here there is no error and no connect affordance; the connector simply does not materialize.

What Should Happen?

Plugin-bundled type: "http" MCP servers should be registered into Customize → Connectors on plugin install/enable, with the standard OAuth authorization flow triggered on first connect — identical to adding the same URL via "Add custom connector," but driven by the plugin manifest. The plugin detail page should also name the bundled connector(s) and link to their Connectors entry rather than showing only a count. No manual claude.ai add-custom-connector step should be required.

Error Messages/Logs

Steps to Reproduce

1. Create a plugin in a GitHub-repo marketplace that bundles a remote MCP server via .mcp.json:

``json
{
"mcpServers": {
"my-mcp": {
"type": "http",
"url": "https://<redacted>.run.app/mcp"
}
}
}
``

1. Add the marketplace and install the plugin in the Desktop app.
2. Enable the plugin; open its detail page — note it shows "It provides 1 connector."
3. Open Customize → Connectors.
4. Observe: the connector is absent; no OAuth prompt is triggered; the server's tools are unavailable in chat and Cowork sessions.

Claude Desktop version: Claude 1.14271.0 (c8f4d8) 2026-06-18T05:47:57.000Z

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.14271.0

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_