Check fuzz workspace formatting in CI

[joostjager]

Extend the rustfmt CI job to check the fuzz workspace.

This covers fuzz alongside the root workspace and lightning-tests.

[ldk-reviews-bot]

👋 Thanks for assigning @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[ldk-claude-review-bot]

This is a straightforward formatting-only PR. All changes in chanmon_consistency.rs are purely whitespace/line-break adjustments to satisfy rustfmt, and the CI change correctly follows the existing pattern for the lightning-tests workspace.

No issues found.

No inline comments were posted. The PR is a clean, minimal change that:

• Adds a cargo fmt --check CI step for the fuzz workspace, following the identical pattern used for lightning-tests
• Applies rustfmt-required formatting fixes to fuzz/src/chanmon_consistency.rs — all changes are strictly cosmetic (line wrapping) with no logic modifications

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.17%. Comparing base (42e198c) to head (2294480).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4582      +/-   ##
==========================================
+ Coverage   87.15%   87.17%   +0.01%     
==========================================
  Files         161      161              
  Lines      109251   109251              
  Branches   109251   109251              
==========================================
+ Hits        95215    95235      +20     
+ Misses      11560    11542      -18     
+ Partials     2476     2474       -2     

Flag	Coverage Δ
fuzzing-fake-hashes	31.20% <ø> (+0.05%)	⬆️
fuzzing-real-hashes	22.92% <ø> (+<0.01%)	⬆️
tests	86.23% <ø> (+0.01%)	⬆️

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