🧹 Refactor exception handling in cold_stats to be more specific

[dioncx]

🎯 What: Replaced the generic except Exception: block with except (OSError, json.JSONDecodeError): in the cold_stats method of Memory.
💡 Why: Catching generic exceptions makes debugging difficult and can silently swallow unrelated errors (like KeyboardInterrupt). Catching OSError and json.JSONDecodeError correctly handles expected file I/O and JSON parsing errors.
✅ Verification: Ran the full test suite (python -m pytest tests/), ensuring no functionality was broken and tests pass successfully.
✨ Result: Improved codebase maintainability by using explicit and safe exception handling.

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PR created automatically by Jules for task 4230600308162818401 started by @dioncx

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