Function project_config_file 

pub fn project_config_file(cwd: &Path, name: &str) -> PathBuf

The candidate context/SYSTEM/APPEND filenames live directly under <cwd>/.rpi/, <cwd>/.pi/, and <agent_dir>/ (no skills/prompts subdir). Re-exports the harness context-file candidates for the system/append discovery path so callers share one source of truth.