[Security] Harden takeRandomFromArray with CSPRNG

[gonzaloriestra]

WHY are these changes introduced?

The takeRandomFromArray utility used Math.random(), which is not cryptographically secure. Hardening it with a CSPRNG provides defense-in-depth for this public utility.

WHAT is this pull request doing?

Replaces Math.random() with globalThis.crypto.getRandomValues() in takeRandomFromArray. Added unit tests for the utility.

How to test your changes?

CI

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct bump type (patch for bug fixes · minor for new features · major for breaking changes) and added a changeset with pnpm changeset add

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PR created automatically by Jules for task 17998295092342495672 started by @gonzaloriestra

[google-labs-jules]

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