v0.5.7
fix: DuckDBGraphWriter.__del__ crash when constructor fails (v0.5.7) Set self._conn = None before duckdb.connect() so __del__ → close() does not raise AttributeError when connect() fails. Also: hasattr check in close() for extra safety. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>