Modernized design and Seamless workflow

[nitrogl]

I added the following features and improvements:

• Modernized design: icons and popup window that provides user-friendly feedback
• Seamless workflow: fingerprint starts automatically (no button required to be pushed manually)
  • First 5 attempts are automatic, then a button "Try again" appears and restarts the fingerprint scan
  • If the fingerprint device is "busy", it waits for it

I tested it on Firefox 153.0.4 (64-bit) - and https://webauthn.io/ and GitHub itself (if that matters)

[Karloss1234]

I like the modern look.

With respect to its position, my thoughts are that this is a high-status dialog box, which is as important as a conventional password request. As password requests are presented as large popups in the middle of the window, I think this passkey popup should be the same, just like Windows Hello:

What was already there achieved this and really just needed a modern look and to go straight to fingerprint press:

--centred/prominent in the current Firefox window/tab, like a password dialog box
--visible without requiring the user to look at the toolbar (some users won't have the extension icon visible)
--it needs a Cancel button, just like a password popup

I have also found a potential bug. On www.webauthn.io, registration succeeds, however when I click on the extension icon in the browser extension bar, it still shows the "Verify it's you, touch the fingerprint reader..." dialog. It is only after doing a follow-up authentication that the extension menu reappears.

Regarding the fingerprint retry handling: I like the effort to make fingerprint failures more resilient, but I have a concern about putting the retry logic at this level. This effectively hides some of the weaknesses of the current fprintd-verify approach rather than addressing/removing those weaknesses.

My concern is that we eventually want WebAuthnLinux to move toward communicating with the fingerprint service through D-Bus directly. If retry/error handling is built around fprintd-verify now, we risk making this workaround part of the architecture and then having to remove/rework it when the D-Bus implementation is introduced.

Many elements of the extension are still experimental/undeveloped, and the use of fprintd-verify is one of those elements. I think users should be able to see the experimental elements, especially as this is a security extension. Keeping the current retry behaviour raw/minimal/honest until we have the underlying D-Bus fingerprint-service interface sorted out seems like the best way forward.