Node.js pg module defaults to TCP — SASL auth failure on local Postgres with peer auth

CLI tool using node-postgres (pg) Pool fails with SASL: SCRAM-SERVER-FIRST-MESSAGE: client password must be a string on a local Postgres instance configured for Unix socket peer auth. The pg module defaults to TCP localhost:5432 when no host is specified, which triggers password auth even though the system is configured for peer auth via Unix socket.