Fix script to work with backups from HA version 2025.7.1+

[sicada]

This PR fixes the script to work with encrypted backup archives from HomeAssistant version 2025.7.1, and presumably newer versions as well (though I have not tested on newer versions).

I've also added a couple lines to print out some helpful info from the manifest (backup.json) since that's what helped me understand how to update this script in the first place.

Example output from the script based on this PR:

$ ./borgify-ha-backup.py -i hass-backup.tar -o hass-output.tar
Encryption key: ****-****-****-****
Reading backup.json manifest from input archive...
Found manifest info: 
    compressed: True
    date: 2025-09-17T18:05:55.360526-00:00
    extra: {'instance_id': '2a51bbc4c91b4ca00070644c777eabcd', 'with_automatic_settings': False}
    homeassistant: {'exclude_database': True, 'version': '2025.7.1'}
    name: hass-backup-2025-09-17
    protected: True
    slug: e7291008
    type: partial
    version: 2
$

[degerrit]

Thanks for the PR - this addresses the same problems I ran into and works for me on 2025.10 too!

I have a separate issue though, which I would address in my own PR (for my specific backup (>6GB sqlite DB) it only works with --compressed, indicating an issue with gzip ISIZE/footer or something).

[degerrit]

Will this break restoring backups of older versions?

[sicada]

I don't know. Unfortunately I don't have any backups that are old enough to test with.