fn parse_tool_call_by_name(message: &str) -> Option<TriggeredToolCall>Expand description
Reads a TOOL_CALL_BY_NAME_PREFIX trigger out of message.
A learner can type the trigger into the chat, so a name no registry claims has to read as an
ordinary message rather than reach the chatbot as a hallucinated call. ! closes the trigger
and so cannot appear in arguments.