Handle ambiguous and nested encrypted QR codes, and hide legacy AES v1 modes

[earthdiver]

Description

• Added support for nested encrypted QR codes
  (currently limited to static QR codes)

• Added support for ambiguous QR codes. You can now choose in Settings how to handle QR codes that could be interpreted as either CompactSeedQR or EncryptedQR (or xprv).

• Handle decrypted text from encrypted QR codes (as an alternative to PR Handle text payloads in encrypted QR decoding #175)

• Hid legacy AES v1 modes from the encryption mode selector

This pull request is categorized as a:

• New feature
• Bug fix
• Code refactor
• Documentation
• Other

Checklist

• I’ve run pytest and made sure all unit tests pass before sumbitting the PR

If you modified or added functionality/workflow, did you add new unit tests?

• No, I’m a fool
• Yes (auto generated by gpt codex)
• N/A

I have tested this PR on the following platforms/os:

• Raspberry Pi OS Manual Build
• SeedSigner OS on a Pi0/Pi0W board
• Other

[earthdiver]

Notes

• Encrypted QR does not support high-capacity QR formats such as BBQR, but in most cases it should be sufficient. (I have not figured out how to support reading both static and animated QR codes in SS.)

• For ambiguous QR codes, CompactSeedQR is prioritized by default. This is to preserve compatibility with previous behavior and to account for the possibility that someone may create an encrypted QR code resembling CompactSeedQR for plausible deniability.

• If the decrypted data does not match CompactSeedQR, xprv, or EncryptedQR, but is valid UTF-8 text, that text will be displayed. However, there are font limitations.

At present, all of these new features are meaningful only when used in combination with Krux’s Datum tool.