Direct port access (http://host:port) fails over Tailscale/VPN and
when ports aren't externally accessible. Now all apps use nginx proxy
paths (/app/name/) on both HTTP and HTTPS.
Also adds missing proxy paths for btcpay, nextcloud, penpot, grafana,
indeedhub. Bumps version to 1.3.1.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>