Your manager should have been fired.

1. It should be impossible for a junior developer to delete anything important.

2. Backups FFS!

3. 6 hour retention window - because why? Because your boss wanted to make sure that if you make a mistake right before you leave, you can't possibly fix it the next day? Disk space is $20 for a terabyte!

4. Hiring people is very very hard these days. And now your junior has had a very good lesson at your expense. They will now take that experience elsewhere.

Is there no adult supervision in your company?