Consider adding a method for creating and/or opening a file

We have this snippet:

https://github.com/axodotdev/axoasset/blob/main/src/compression.rs#L33

We could replace this with a method from `LocalAsset` that `create`s a file and then returns it.

Start at src/compression.rs#L33 and inspect the LocalAsset API to understand how the existing file creation and opening flow works. Define the intended method boundary and verify that the snippet can use it while preserving current behavior; the issue does not name a test, so locate the relevant asset or compression tests before confirming completion.

Written by the indexing model from the issue text.