5 tests pin the SoulSync standalone client surface — the
structurally-different one (no auth, no API, no library scan).
is_connected just checks os.path.isdir(transfer_path).
ensure_connection reloads config first so the user changing
the transfer_path takes effect without a process restart.
get_all_album_ids returns a set of MD5-hashed string ids
matching cross-server uniform set semantics.
