transformers 5.x deprecated PretrainedConfig.torch_dtype; both getter and setter log a warning on every load. Add set_config_dtype/get_config_dtype helpers (configuration_vibevoice.py + modules/dtype_utils.py) that use config.dtype on v5 and torch_dtype on 4.x, and route the loader/external_loader writes plus the 5 vendored modeling reader blocks through them. +17 regression tests incl. no-warning assertions on the real load path.