Make Caddy Admin API Endpoint Exposing Secure

[raghavyuva]

Describe the bug

The Caddy Admin API endpoint is currently exposed without proper access controls, making it potentially vulnerable to unauthorized access and abuse.

To Reproduce

Steps to reproduce the behavior:

• Start a Caddy server with default settings.
• Access the Admin API endpoint at http://localhost:2019/config/.
• Observe that configuration data is returned without any authentication mechanism.

Expected behavior

The Admin API should be protected by authentication and/or IP restriction by default, or provide clear documentation and options to secure the endpoint.