Function hook_socket_path 

pub fn hook_socket_path(base_dir: &Path, worktree_root: &Path) -> PathBuf

Where the elected listener binds. Prefers a sockets/ sibling of locks/ under the shared DB dir; diverts to $XDG_RUNTIME_DIR/rag-rat/ then the OS temp dir when the result would exceed the sun_path budget. Hook clients compute the same path independently, so this must stay deterministic for a given (base_dir, worktree_root) and environment.