Exceptions

Exception	Thrown when
`CommandDefinitionException`	Invalid or conflicting command definition at registration time
`NamespaceDefinitionException`	Invalid namespace definition, or a namespace/command name collision, at registration time
`CommandMappingException`	A `MapTo`/`MapToSignature` correlation is invalid (unmapped option or type mismatch) at registration time
`CommandParseException`	Input could not be parsed into a valid command structure
`CommandInputException`	User input is rejected — fails a constraint, or references an undefined or duplicate option
`OptionArgumentException`	Option argument cannot be converted to the declared type
`CommandExecutionException`	The command being executed has no `Handler` (or `AsyncHandler`) defined
`RangeOverflowException`	Input exceeds the scanner’s maximum length (or an internal buffer capacity)