Add OSS Scanner build environment and threat model

.oss-scanner/start-postgres.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# Start the local PostgreSQL server used by the test suite and the app (see .oss-scanner/Dockerfile).
+set -euo pipefail
+
+pg_ctlcluster 15 main start 2>/dev/null || true
+until pg_isready -h 127.0.0.1 -p 5432 -q; do sleep 0.5; done
+echo "PostgreSQL is running on 127.0.0.1:5432 (user root, password root, database laravel)"