🔒 Fix Insecure Randomness for Cryptographic Salt in App.tsx

[jason420247]

🎯 What: Fixed an insecure randomness vulnerability in TrinityKeystore.getVector() within App.tsx where an insecure Math.random() was used to generate salt values.
⚠️ Risk: Math.random() generates predictable values that are highly vulnerable to seed-reconstruction attacks, putting cryptographic salt integrity at risk.
🛡️ Solution: Replaced Math.random() with crypto.getRandomValues() utilizing the Web Crypto API, resolving the provider safely across different browser and Node.js environments.

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PR created automatically by Jules for task 156326424397801300 started by @jason420247

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