Unable to get MCP servers depending on OAuth to work

I can't figure out how to configure MCP servers which depend on OAuth to get working. A simple one to test is the Github Copilot MCP which works without configuring anything.

Works
```json
"github-mcp-server": {
"type": "http",
"url": "https://api.githubcopilot.com/mcp",
"gallery": "https://p-ne1apim-apicenter.data.swedencentral.azure-apicenter.ms/workspaces/default",
"version": "Original",
"headers": {
"X-MCP-Toolsets": "actions,git,pull_requests,repos",
"X-MCP-Readonly": "true"
}
},
```

Does not work
```json
"githu-mcp-server2": {
"type": "http",
"url": "https://p-ai-gateway.azure-api.net/default/toolservers/github/mcp",
"headers": {
"api-key": ""
},
"gallery": "https://p-ne1apim-apicenter.data.swedencentral.azure-apicenter.ms/workspaces/default",
"version": "v0"
}
```

I tried configuring the authentication to "None" - this results i :
```
2026-07-31 13:58:19.769 [info] Connection state: Error 404 status sending message to https://p-ai-gateway.azure-api.net/default/toolservers/github/mcp: { "statusCode": 404, "message": "Federation tools/list failed: required endpoint 'Github' returned error: Endpoint 'Github' init returned HTTP 401." }
```

When attempting to configure OAuth 2.0 with "Auto discover" I get the following settings:

Just put "placeholder", "placeholder" in clientid and secret.

This ends up with:

2026-07-31 14:04:55.674 [info] Connection state: Error 404 status sending message to https://p-ai-gateway.azure-api.net/default/toolservers/github/mcp: { "statusCode": 404, "message": "Federation tools/list failed: required endpoint 'Github' returned error: OAuth2 endpoint 'Github' has no valid connection (ReconnectRequired)." }

Not sure how this is meant to be set up, and why is a client id and client secret needed in this case?

Start by reproducing the OAuth and unauthenticated requests to https://p-ai-gateway.azure-api.net/default/toolservers/github/mcp using the configurations and error logs in this issue. Inspect how the Github endpoint is initialized and how OAuth discovery handles client credentials. Done means the MCP server connects successfully with a documented, working configuration.

Written by the indexing model from the issue text.