Declare __all__ in aio.py

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: antoineleclair

src/sqlalchemydqlite/aio.py

@@ -11,6 +11,8 @@
 
 from sqlalchemydqlite.base import DqliteDialect
 
+__all__ = ["DqliteDialect_aio"]
+
 
 class AsyncAdaptedCursor:
     """Adapts an AsyncCursor for SQLAlchemy's greenlet-based async engine.