Add more LiquidCache tests for TTL and expiration behavior

[FlaringPhoenix]

Motivation

• Improve test coverage around TTL inspection, disabled expiration, manual deletes, and TTL updates to prevent regressions in expiration logic.
• Validate lifecycle hooks like onExpire and runtime options such as autoRenew to ensure expected production semantics.

Description

• Added new test cases in test/LiquidCache.spec.ts to cover: remaining TTL reporting for present/missing keys, disabled expiration (null TTL), that onExpire is not called for manual delete, clearing TTL when updating a key with null, and autoRenew behavior on get.
• Tests use LiquidCache constructed with option objects (e.g. defaultTTL, onExpire, autoRenew) to exercise runtime options.
• Kept tests asynchronous where needed using setTimeout to observe expiration side effects.

Testing

• Ran npm test (which runs npm run build then the test suite); TypeScript build/tests failed due to duplicate identifier errors from conflicting ambient types in @types/jasmine and @types/mocha.
• No test failures from the new specs themselves were observed locally because the type conflicts prevented the test run from completing.

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Codex Task