Function extract_paths 

pub fn extract_paths(session: &Session) -> Vec<(String, DateTime<Utc>)>

Extract raw path strings from a single session.

Sources (most-trusted first):

• tool_args of trajectory steps (paths the agent actually operated on)
• user messages (explicit mentions)

Each returned (path, timestamp) pair is one “touch”. A single message may contribute several touches if it references several paths.