Docs: add lavarand

[tadeubas]

What is this PR for?

Add lavarand info to new mnemonic by camera

Changes made to:

• [ ] Code
• [ ] Tests
• [x] Docs
• [ ] CHANGELOG

Did you build the code and tested on device?

• [ ] Yes, build and tested on

What is the purpose of this pull request?

• [ ] Bug fix
• [ ] New feature
• [x] Docs update
• [ ] Other

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 97.37%. Comparing base (e6b895e) to head (59c3769). :warning: Report is 4 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #764      +/-   ##
===========================================
- Coverage    97.37%   97.37%   -0.01%     
===========================================
  Files           83       83              
  Lines        10525    10521       -4     
===========================================
- Hits         10249    10245       -4     
  Misses         276      276              

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[odudex]

I didn't get why this should be in Krux documentation.

[tadeubas]

Lavarand reference provides valuable context for understanding the rationale and legitimacy of Krux's image-based entropy generation method. It connects our "experimental" feature to a well-known, historically validated approach to physical entropy collection in cryptography.

This is important because "entropy from camera" can sound hand-wavy or insecure to a reader without context and by referencing Lavarand, we implicitly answer the question:

• Is using a camera img as an entropy source legitimate? Yes, this idea has decades of precedent in cryptographic systems!
• And adds a reference point if someone wants to audit or discuss the entropy assumptions.