`everyvoice checkpoint inspect hifigan_universal_v1_everyvoice.ckpt` creates empty directories in the current dir

### Bug description

Inspecting our universal HFGL model causes the creation of these empty directory in your current working directory:
```
.
├── logs_and_checkpoints/
├── preprocessed/
│  └── YourDataSet/
...
```

### How to reproduce the bug

```python
everyvoice checkpoint inspect /hifigan_universal_v1_everyvoice.ckpt
```

### Error messages and logs

Between printing the config and the arch, these two messages occur:
```
2025-08-28 17:02:56.284 | INFO | everyvoice.config.validation_helpers:directory_path_must_exist:89 - Directory at logs_and_checkpoints does not exist. Creating...
2025-08-28 17:02:56.286 | INFO | everyvoice.config.validation_helpers:directory_path_must_exist:89 - Directory at preprocessed/YourDataSet does not exist. Creating...
```

Note that in the config that gets printed from this universal checkpoint, this line occurs under `"preprocessing"`:
```
"save_dir": "preprocessed/YourDataSet",
```

which at least explains where the folder name `YourDataSet` comes from, though it really should still not get created!

### Environment

Current environment

# Please paste the output of `everyvoice --diagnostic` here

# EveryVoice Diagnostic information

### More info

_No response_

Run `everyvoice checkpoint inspect /hifigan_universal_v1_everyvoice.ckpt` and start by reading `everyvoice.config.validation_helpers:directory_path_must_exist` around line 89. Trace how the printed preprocessing `save_dir` and `logs_and_checkpoints` paths are validated; done means inspection prints the config and architecture without creating directories in the current directory.

Written by the indexing model from the issue text.