Function quote_in_system_note 

pub fn quote_in_system_note(text: &str) -> String

Text that goes inside one of srv’s own [AgentMux] system notes but was not written by srv: another agent’s claim note or topic, a file path, a branch or agent name. Sanitized like a delivered body, flattened to one line (every control character and line break becomes a space, runs of whitespace collapse), and with marker delimiters quoted, so it can neither start a line of its own nor open an [AgentMux] note, a jekt block or a broadcast header.