Audio export should not override existing files if cancelled

Your idea

Currently, the export target is immediately cleared when exporting to audio. For 80% of the progress bar, no data is actually written to the file (only a buffer is filled).

Instead, pressing cancel should not clear the file until the encoding process has started. The final 20% is encoding and cannot be interrupted, so once writing to the file starts it will run to completion.

Problem to be solved

• Overriding the wrong export file causes data loss that could be prevented otherwise by cancelling quickly.
• When the export takes a long time, it can be cancelled and a previous version of the score is still available.

Prior art

It is common in other software to preserve existing files if exporting is cancelled. I think this is often done using temp files, but in this case it would be sufficient to overwrite the file at a later stage during the export process.

Additional context

No response