Add support for PWA

[AAEE86]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

PWA (Progressive Web App) is an application that can provide a native application-like experience on web pages and mobile devices. PWA combines the advantages of web pages and mobile applications, which can be accessed through the browser or installed on the device like a native application. The core concept of PWA is Progressive Enhancement, that is, the application will provide a better experience with the enhancement of the user's device and browser capabilities.

2. Additional context or comments

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3. Can you help us with this feature?

• I am interested in contributing to this feature.

[backrunner]

I think at least the built-in chat web app should support PWA, Coze has a great support for PWA and I can easily access my agent through the dock of macOS or home screen of my smartphone, but I can't do that with Dify.
Add a service worker will not take a long time to develop, but it can bring a much better UX to users.