Document L4 service modes, header authentication, and access restrictions

[lixmal]

Summary

• Add L4 (TCP, UDP, TLS) service mode documentation to the reverse proxy overview, including service mode descriptions, target properties, port allocation, auto-assigned vs custom ports, and SNI-based port sharing behavior
• Add header authentication section (Basic Auth, Bearer Token, Custom Header presets) to the authentication page
• Add access restrictions section (IP CIDR and country-based allow/blocklists) to the authentication page, with correct reference to the Access Control tab in the dashboard
• Update expose-from-cli page with L4 protocol support, --with-external-port flag, and L4 examples (database tunnel, game server, TLS passthrough)
• Update access logs page with unified field table covering both HTTP and L4 log entries, deny reason reference, and L4-specific fields (bytes uploaded/downloaded, protocol)
• Update related page links across custom-domains and expose-from-cli to mention header auth

Screenshots

Overview (reverse-proxy/index.mdx)

Authentication (reverse-proxy/authentication.mdx)

tion.mdx)

Expose from CLI (reverse-proxy/expose-from-cli.mdx)

Access Logs (reverse-proxy/access-logs.mdx)