- Added extra HTTP headers and security configurations in the Nginx proxy for Headscale.
- Improves websocket handling, security headers, and HTTPS redirection.
- Introduced OIDC settings in Headscale, including allowed domains, client ID, client secret path, and issuer.
- Enables support for OpenID Connect authentication.
- Included `headscale.nix` in the MX system configuration for VPN management.
- Added Nginx and ACME configuration to route traffic securely to Headscale.
- Ensures Headscale is enabled with required settings and packaged in the system.
