docs(update_local_appstore): update error message for 1panel path

- improve error message for missing 1panel installation path in both Chinese and English
- add usage example to guide users on how to specify the path correctly

update_local_appstore.sh

@@ -49,7 +49,7 @@ if $USE_ZH; then
     MSG_ERR_PATH_INVALID="错误: 指定的路径 '%s' 不存在或不是目录"
     MSG_ERR_PATH_REQUIRE="错误: --1panel-path 参数需要指定路径"
     MSG_ERR_MULTI_PATH="错误: 只能指定一个 --1panel-path 参数"
-    MSG_ERR_NO_1PANEL="未找到1Panel的安装路径"
+    MSG_ERR_NO_1PANEL="未找到1Panel的安装路径, 使用 --1panel-path 设置1Panel的安装路径, 例如 --1panel-path /opt"
     MSG_LATEST_COMMIT="本地仓库的最新提交: "
     MSG_NOTE_UNKNOWN="注意: 未知参数 %s 被忽略"
     MSG_WARN_APP_MISSING="警告: 应用 '%s' 在仓库中不存在"
@@ -80,7 +80,7 @@ else
     MSG_ERR_PATH_INVALID="Error: Specified path '%s' does not exist or is not a directory"
     MSG_ERR_PATH_REQUIRE="Error: --1panel-path parameter requires a path"
     MSG_ERR_MULTI_PATH="Error: Only one --1panel-path parameter can be specified"
-    MSG_ERR_NO_1PANEL="No installation path found for 1panel"
+    MSG_ERR_NO_1PANEL="No installation path found for 1panel, use --1panel-path to specify the installation path, e.g., --1panel-path /opt"
     MSG_LATEST_COMMIT="Latest commit in the local repository:"
     MSG_NOTE_UNKNOWN="Note: Unknown parameter %s ignored"
     MSG_WARN_APP_MISSING="WARNING: App '%s' does not exist in repository"