5.3.1

[github-actions]

This is the release candidate for version 5.3.1.

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Note

Low Risk
Low risk release bookkeeping only: version metadata and changelog updates, with no runtime code changes.

Overview
Prepares the 5.3.1 release by bumping package.json version to 5.3.1 and adding a new CHANGELOG.md section for 5.3.1 (Windows CRLF validation fix).

Updates changelog link references so [Unreleased] compares from v5.3.1 and adds the v5.3.1 compare link.

^{Written by Cursor Bugbot for commit 355f0f3. This will update automatically on new commits. Configure here.}

[cryptodev-2s]

LGTM!