Support opening local workflows via direct browser URL

### Feature Idea

Issue Title / 标题
[Feature Request] Support opening local workflows via direct browser URL
[功能请求] 支持通过浏览器URL直接打开本地已保存的工作流

Problem Description / 问题描述
English: Currently, to switch between saved workflows, users must use the "Load" button and navigate through the file system dialog every time. This process can be inefficient, especially when frequently switching between a set of known workflows.
中文： 目前，要切换已保存的工作流，用户每次都必须使用“加载”(Load) 按钮并在文件系统对话框中导航。这个过程效率较低，特别是在需要频繁切换几个已知的工作流时。

Proposed Solution / 建议的解决方案
English: I propose adding support for a direct URL scheme to open locally saved workflows. By simply appending the workflow filename as a parameter to the ComfyUI server URL, the interface would automatically load the specified JSON file from the default workspace directory.
中文： 我建议增加对直接URL方案的支持，用以打开本地保存的工作流。通过简单地将工作流文件名作为参数附加到ComfyUI服务器URL后，界面应能自动从默认的 workspace 目录加载指定的JSON文件。

Example / 示例:

Current URL / 当前网址: http://127.0.0.1:8188/

Proposed URL / 建议网址: http://127.0.0.1:8188/?workflow=my_awesome_workflow.json

Visiting this URL would automatically load the my_awesome_workflow.json file from the ComfyUI/web/workspace/ folder.

访问此URL应自动加载 ComfyUI/web/workspace/ 文件夹中的 my_awesome_workflow.json 文件。

Benefits / 好处
English:

Efficiency: Allows for quick switching of workflows by just changing the browser URL or using bookmarks.

Integration: Can be used by external tools or scripts to launch ComfyUI with a specific workflow automatically.

Usability: Creates shareable local links that others on the same network can use to open a workflow on your running server instantly.

中文:

高效: 只需更改浏览器URL或使用书签即可快速切换工作流。

集成: 外部工具或脚本可以使用此功能自动启动ComfyUI并加载特定工作流。

可用性: 可以创建可分享的本地链接，同一网络下的其他用户可以通过该链接立即在您运行的服务器上打开某个工作流。

Implementation Considerations / 实现考虑
English:

The parameter name could be something like ?workflow= or ?load_workflow=.

It should only read from the designated workspace directory for security reasons.

Robust error handling should be in place (e.g., displaying a message if the specified .json file is not found).

The current functionality of the main page (http://127.0.0.1:8188/ with no parameters) should remain unchanged, loading a blank state or the last opened workflow as it does now.

中文:

参数名可以是 ?workflow= 或 ?load_workflow=。

出于安全考虑，应仅从指定的 workspace 目录中读取文件。

应加入健壮的错误处理（例如，如果未找到指定的.json文件，则应显示错误信息）。

主页（http://127.0.0.1:8188/ 无参数）的当前功能应保持不变，像现在一样加载空白状态或最后打开的工作流。

Thank you for your consideration! This would be a powerful quality-of-life improvement for power users.
感谢您的考虑！这对于高级用户来说将是一个极佳的体验提升。

### Existing Solutions

_No response_

### Other

_No response_