Fix GHL debug config auth lookup

[groksrc]

Summary

Fix debug_config so it resolves the registered OAuth service before reading auth settings. The opportunity tools register a getter (lambda: oauth_service) rather than the service object itself, so the health-check tool was failing with 'function' object has no attribute 'settings' when called through MCP.

Impact

• Restores the debug_config MCP health-check tool.
• Keeps the existing registration style and normal GHL tool behavior unchanged.
• Leaves unrelated local untracked recon scripts out of the PR.

Validation

• uv run pytest tests/test_mcp_mode_startup.py tests/test_mcp_endpoints.py