--path-style=auto rule settings

https://github.com/lusingander/stu/issues/57#issuecomment-2721030990

It would be nice if `--path-style` could be set automatically depending on the `endpoint-url` specified by the user.

```toml
path_style_rules = [
  { match = "localhost", type = "contains", path_style = "always" },
  { match = "https://storage.example.com", type = "exact", path_style = "never" },
]
```