Subagent parsing is missing support for oauth fields

We want to support agents like below. Current code is parsing only subset of fields from MC server schema.

kind: local
name: spanner-test-agent
description: An agent to test Spanner MCP with auth
mcp_servers:
spanner:
url: https://spanner.googleapis.com/mcp
type: http
auth:
type: google-credentials
scopes:
- https://www.googleapis.com/auth/cloud-platform
timeout: 30000

You are a Spanner test agent. You have access to the Spanner MCP server.
Your task is to list configs under the span-cloud-testing project.