🔒 Fix Insecure Randomness in TrinityKeystore

[jason420247]

🎯 What: Replaced insecure Math.random() usage in TrinityKeystore.getVector() with Web Crypto API's getRandomValues().

⚠️ Risk: Math.random() uses a non-cryptographic PRNG that produces predictable values. An attacker capable of predicting salt values could compromise cryptographic operations or keystore vectors.

🛡️ Solution: Implemented cryptoObj.getRandomValues() with cross-environment fallbacks (window.crypto / globalThis.crypto) to generate cryptographically secure random values.

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PR created automatically by Jules for task 15561568360184004983 started by @jason420247

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