🧪 [testing improvement] Cover and secure uuid generation

[Tcode-Motion]

🎯 What: The testing gap addressed was an uncovered unwrap() in stdlib/src/uuid.rs which was vulnerable to panic if SystemTime calculates a time before the UNIX epoch.
📊 Coverage: A test test_uuid_module has been added in stdlib/tests/stdlib_tests.rs to assert that uuid_v4 generates validly formatted UUID-like strings, covering the happy path.
✨ Result: Increased code reliability and test coverage by converting the panic point to a default fallback and explicitly testing module output.

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PR created automatically by Jules for task 5585788007734510867 started by @Tcode-Motion

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