HF RL Explorer

Bug: UnknownArgumentValueParser triggers error/downcast failure for an absent boolean flag

Bug: UnknownArgumentValueParser triggers error/downcast failure for an absent boolean flag: a task in LegoFlow-SWE (Harbor dataset). When attaching UnknownArgumentValueParser (or the deprecated UnknownValueParser ) to a boolean flag (e.g., ArgAction::SetTrue ), the parser incorrectly interferes…

The task

When attaching `UnknownArgumentValueParser` (or the deprecated `UnknownValueParser`) to a boolean flag (e.g., `ArgAction::SetTrue`), the parser incorrectly interferes with normal parsing even when the flag is **not** provided on the command line. This leads to two distinct problems:

Part of Lego-X/LegoFlow-SWE.