on_conversion_failed property Leave feedback

The event handler invoked when a conversion fails.

Honored for back‑compat: the value is merged into the internal events bag at Converter construction (mapping to ConversionEvents.on_document_failed) and is overridden if the same handler is also set on the events constructor parameter.

@property
def on_conversion_failed(self):
    ...
@on_conversion_failed.setter
def on_conversion_failed(self, value):
    ...

• class ConverterSettings