Warning: This build has drifted.
The coverage report for this pull request build may be inaccurate because its base commit is no longer the HEAD of its target branch.
This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

    • Learn more: For more information on this, see Tracking coverage changes for pull request builds.
    • Fix now: For a quick fix, rebase this PR at GitHub. Your next report should be accurate.
    • Prevent going forward: To avoid this issue with future PRs, see these Recommended CI Configurations.

solver: add defensive coeffBits validation in backSubstitute

Validates that sb.coeffBits is 32, 64, or 128 at the point of use
in backSubstitute(), complementing the existing validation in the
newStandardBander constructor.

Addresses review feedback from @DhruvilK7 on PR #40.