test(cache): verify TTLCache throws RangeError for negative TTL (JhaSourav07#1398) (JhaSourav07#1883)

## Description
Added a specific test case in lib/cache.test.ts to verify that setting a
cache value with a negative TTL (e.g., -5000) correctly throws a
RangeError. This improves test coverage for boundary inputs and ensures
the TTLCache implementation behaves safely under extreme values,
satisfying all acceptance criteria for the issue.

Fixes JhaSourav07#1398 

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Author: JhaSourav07

lib/cache.test.ts

@@ -426,6 +426,13 @@ describe('TTLCache', () => {
   });
 
   describe('edge cases and error handling', () => {
+    // FIX: New test explicitly targeting the -5000 boundary for Issue #1398
+    it('throws RangeError when setting a value with -5000 TTL', () => {
+      const cache = new TTLCache<string>();
+      expect(() => cache.set('key', 'value', -5000)).toThrow(RangeError);
+      cache.destroy();
+    });
+
     it('throws RangeError when ttlMs is 0 or negative', () => {
       const cache = new TTLCache<string>();
       expect(() => cache.set('key', 'value', 0)).toThrow(RangeError);
@@ -473,6 +480,7 @@ describe('TTLCache', () => {
       expect([null, 'lived']).toContain(result);
       cache.destroy();
     });
+
     it('does not throw when ttlMs is Number.EPSILON', () => {
       const cache = new TTLCache<string>();