DigitalOcean doesn't provision swap by default and the $4/mo (512MB)
droplet has little headroom once Docker + Asterisk + coturn are
running. The installer now detects RAM <=2GB with no existing swap and
offers to add a persistent 2GB swapfile before doing anything else, so
that tier is safe to use instead of risking an OOM kill under load.
README updated with the corrected sizing table.
Duplicates services/asterisk.sh (left untouched) into a DO-specific
variant: auto-detects the droplet's public IP/ID via the DO metadata
service, always assumes a public FQDN (no LAN/VLAN prompts), offers to
provision a matching DigitalOcean Cloud Firewall via doctl (never
touching one that's already attached), and documents droplet sizing,
firewall rules, and Sipnetic client setup in the generated README.
Claude