Switch frontend container to production-aware runtime mode

frontend/docker-entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+# Frontend runtime entrypoint.
+# Uses APP_ENV to select development or production Vite startup mode.
+
+set -eu
+
+APP_ENV_VALUE="${APP_ENV:-development}"
+HOST_VALUE="${FRONTEND_HOST:-0.0.0.0}"
+PORT_VALUE="${FRONTEND_PORT:-5173}"
+
+if [ "$APP_ENV_VALUE" = "production" ]; then
+  npm run build
+  exec npm run preview -- --host "$HOST_VALUE" --port "$PORT_VALUE"
+fi
+
+exec npm run dev -- --host "$HOST_VALUE" --port "$PORT_VALUE"