Path parsing, hop counting, per-path distances and node location by prefix (ten functions and the hex-token set, about 450 lines) move verbatim from utils.py to mesh_paths.py, and utils re-exports every one of them, so existing imports and module.utils lookups are unchanged. The two functions that need calculate_distance import it from utils at call time, which avoids a circular import and keeps patches of modules.utils.calculate_distance effective. The five tests that patched _get_node_location_from_db to steer calculate_path_distances now patch it where it lives, and a companion test goes through the old modules.utils entry point. utils.py drops to 1,798 lines.
