Evaluate replacing Traefik with Caddy for reverse proxy

[mairas]

Summary

Consider replacing Traefik with Caddy as the reverse proxy solution for HaLOS.

Motivation

Caddy supports automatic local CA (Certificate Authority), which would be a significant benefit for HaLOS devices operating in isolated networks. This feature allows Caddy to:

• Automatically generate and manage TLS certificates for local domains
• Serve as a local CA without requiring external certificate authorities
• Provide HTTPS out of the box for devices that may never be connected to the internet

For marine and other isolated device networks, this eliminates the friction of certificate management while still providing secure connections.

Context

This suggestion came from a discussion with Teppo Kurki about the relative strengths of Traefik vs Caddy.

Tasks

• Research Caddy's local CA capabilities in detail
• Compare feature parity between current Traefik setup and Caddy
• Evaluate migration complexity
• Test Caddy in a development environment
• Document any breaking changes for existing users

References

• Caddy documentation on automatic HTTPS
• Caddy local CA / internal certificates