Add Krux decrypt to the GUI (for QR code and SD card)

[tadeubas]

The full script is that needs to interact with the GUI: https://gist.github.com/odudex/e86fb4d97cc2c161803ad01f7b43e237

Doc about Krux Encrypted Mnemonics: https://selfcustody.github.io/krux/getting-started/features/encrypted-mnemonics/

[qlrd]

I'm reviewing all the old stuff that I haven't resolved...

I don't remember the details and I'll try to infer what you meant.

Is your proposal to capture an encrypted qrcode on the device, decode it and show the contents in the installer?

[tadeubas]

Sorry for the late reply. The idea is to be able to decrypt a Krux QRCode or an encrypted mnemonic stored on the SD card. To be able to do what a Krux device is capable of doing, but without the Krux device!

This is important because the user may have an encrypted backup (QR or saved on the SD), but no longer have the device to decrypt it (this will also address a workaround for a rare bug in v23.09.0 that may require brute-forcing to recover the mnemonic).