[Bug Report] PWA is unavalible on some platforms and browsers due to manifest requirements chaging

[miawgogo]

Describe the bug

When using stash on android with Fennec F-Droid there is no option to install stash as a PWA and adding it to the home screen also only adds it as a shortcut showing the browser UI. I confirmed that fennec/firefox mobile supports PWAs by installing google maps as a PWA

Im going to include a screenshot of the chrome developer tools as it shows all the issues with the manifest

I think it could largely be solved by taking this icon from the site repo and adding it to the UI(I'll make a PR to do this after discussion) and using it instead as it simplifies a lot.

To Reproduce
Steps to reproduce the behavior:

1. Open it on firefox for Android
2. the menu says "add to home screen" instead of "Add App to home screen"
3. after adding it, it shows the browser UI when installed

Expected behavior
Firefox should say "Add App to home screen"

Stash Version: (from Settings -> About): v0.27.2

Smartphone (please complete the following information):

• Device: One Plus 9 Pro
• OS: Lineage OS 12(Android 15)
• Browser: Fennec F-Droid
• Version: 135.0

Extra Screenshot