fix(dev): 等待 PostgreSQL 容器就绪

数据库初始化脚本在容器停止时主动启动，并在执行 psql 前等待 PostgreSQL 就绪；若容器提前退出或超过等待时间则返回明确错误。

验证：bash -n、ShellCheck、git diff --check 与 pnpm db:create 通过。

scripts/create-database.sh

@@ -23,6 +23,35 @@ fi
 PGUSER="${AI_GATEWAY_PG_USER:-easyai}"
 DB_NAME="${AI_GATEWAY_DATABASE_NAME:-easyai_ai_gateway}"
 
+wait_for_postgres() {
+  local status
+
+  status="$(docker inspect "$CONTAINER" --format '{{.State.Status}}')"
+  if [[ "$status" != "running" ]]; then
+    echo "[ai-gateway] starting PostgreSQL container: ${CONTAINER}"
+    docker start "$CONTAINER" >/dev/null
+  fi
+
+  for _ in {1..30}; do
+    if docker exec "$CONTAINER" \
+      pg_isready -U "$PGUSER" -d postgres >/dev/null 2>&1; then
+      return 0
+    fi
+
+    status="$(docker inspect "$CONTAINER" --format '{{.State.Status}}')"
+    if [[ "$status" != "running" ]]; then
+      echo "[ai-gateway] PostgreSQL container stopped before becoming ready: ${CONTAINER} (${status})" >&2
+      return 1
+    fi
+    sleep 1
+  done
+
+  echo "[ai-gateway] timed out waiting for PostgreSQL container: ${CONTAINER}" >&2
+  return 1
+}
+
+wait_for_postgres
+
 version_num="$(
   docker exec "$CONTAINER" \
     psql -U "$PGUSER" -d postgres -tAc "SHOW server_version_num" \