auto-claude: subtask-2-1 - Create tests for cache.ts (TTL, get/set, expiration logic)

- Created comprehensive test suite for cache.ts covering:
  - set() and get() operations with various data types
  - TTL expiration logic (default, custom, and edge cases)
  - has() method for checking key existence
  - delete() method for removing individual keys
  - clear() method for removing all keys
  - Expiration boundary testing
  - Different TTL values for different items
  - TTL reset when items are overwritten
- Fixed vitest.config.ts to include src/utils/** tests
- Fixed tsconfig.json to include src/utils/** files
- Used vi.useFakeTimers() for deterministic time-based testing
- All tests properly isolated with beforeEach/afterEach hooks

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.auto-claude-status

@@ -0,0 +1,25 @@
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+    "total": 8,
+    "in_progress": 1,
+    "failed": 0
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+  "phase": {
+    "current": "Utility Functions Tests",
+    "id": null,
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