Add production and dev Caddyfiles for FrankenPHP:
- Caddyfile: HTTP-only on :8080, auto_https off, worker mode
- Caddyfile.dev: same but without worker directive so Xdebug
step-debugging remains functional; Caddy debug logging enabled
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>