[Security] Harden random selection in takeRandomFromArray

[gonzaloriestra]

This PR hardens the takeRandomFromArray utility in @shopify/cli-kit by replacing the non-cryptographically secure Math.random() with a CSPRNG (globalThis.crypto.getRandomValues()). It also implements rejection sampling to eliminate modulo bias, ensuring a truly unbiased distribution. Additionally, the function now safely handles empty arrays by returning undefined and updating its type signature accordingly.

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PR created automatically by Jules for task 3547986643681095491 started by @gonzaloriestra

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[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/public/common/array.d.ts

@@ -5,7 +5,7 @@ import type { List, ValueIteratee } from 'lodash';
  * @param array - Array from which we'll select a random item.
  * @returns A random element from the array.
  */
-export declare function takeRandomFromArray<T>(array: T[]): T;
+export declare function takeRandomFromArray<T>(array: T[]): T | undefined;
 /**
  * Returns a copy of the array deleting the elemements that are undefined.
  *