Caddy's email directive requires a non-empty argument. Since ACME_EMAIL
wasn't set, Caddy failed to parse the config. Email is optional for
Let's Encrypt — remove the directive entirely and document it as a
manual opt-in comment.
Caddy's built-in ACME support handles TLS automatically — no CF_API_TOKEN,
no Cloudflare account, no DNS plugin needed. Requires ports 80+443 forwarded
to the Pi and ACME_EMAIL set in infra/.env.
start.sh now generates proxy/caddy.json at launch time with Let's Encrypt
automatic HTTPS (HTTP-01 or TLS-ALPN-01 challenge — no Cloudflare needed).
Reads DOMAIN_SUFFIX and ACME_EMAIL from infra/.env before starting.
Added infra/.env.example to document required vars.
