Constant PROJECT_CONFIG_DIR_NAME 

pub const PROJECT_CONFIG_DIR_NAME: &str = ".pi";

The project-local config dir name. Mirrors pi’s .pi/ (NOT .rpi/) so a copied pi project directory drops in and works: skills under <cwd>/.pi/skills, prompts under <cwd>/.pi/prompts, SYSTEM.md/APPEND_SYSTEM.md under <cwd>/.pi/. The global config lives under agent_dir() (~/.rpi/agent), which IS .rpi — see config.rs.