Function subagents_json_path 

pub fn subagents_json_path(root: &Path, project: &str, agent: &str) -> PathBuf

Absolute path to the rendered Claude Code --agents JSON for one agent (#383 Phase 3a). Lives beside the settings file under state/claude/ and is written only when the agent declares subagents:; the wrapper passes it via --agents "$(cat <path>)" when the file exists.