Add Ubuntu deployment workflow

scripts/start-frontend.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Ubuntu/systemd 前端启动入口。
+# 运行生产构建后的 Next.js 服务；开发调试继续使用 scripts/start-webui.sh。
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+ENV_FILE="${ROOT_DIR}/.env.deploy"
+
+if [[ -f "${ENV_FILE}" ]]; then
+	# shellcheck disable=SC1090
+	source "${ENV_FILE}"
+else
+	echo "Missing deploy config: ${ENV_FILE}" >&2
+	echo "Run: bash scripts/deploy-ubuntu.sh" >&2
+	exit 1
+fi
+
+BACKEND_HOST="${CLAW_BACKEND_HOST:-127.0.0.1}"
+BACKEND_PORT="${CLAW_BACKEND_PORT:-8765}"
+FRONTEND_HOST="${CLAW_FRONTEND_HOST:-0.0.0.0}"
+FRONTEND_PORT="${CLAW_FRONTEND_PORT:-3000}"
+
+export CLAW_API_URL="${CLAW_API_URL:-http://${BACKEND_HOST}:${BACKEND_PORT}}"
+
+cd "${ROOT_DIR}/frontend/app"
+exec npm run start -- --hostname "${FRONTEND_HOST}" --port "${FRONTEND_PORT}"