disconnect method
Closes the active database connection.
If no connection is active, this method does nothing gracefully.
Sets the internal _connection reference to null.
{@tool example}
await reader.connect();
// ... use reader ...
await reader.disconnect();
{@end-tool}
@return A Future that completes when the connection is closed or if it was already closed.
Implementation
Future<void> disconnect() async {
// Use `?.` for safe invocation if _connection is already null.
await _connection?.close();
_connection = null; // Ensure reference is cleared
_logger.info('Disconnected from database');
}