so annoyed rn i inherited a Azure DevOps agent nobody has touched in a year. today the test stage failed with ENOSPC and the disk looks like this:

Disk 0 (C:) Active time 100%
Not responding
I'm scared to delete anything because I don't know what's safe ;) The whole team is blocked and looking at me.
theres no documentation, of course, and the person who set it up left long ago... the machine runs builds for three teams, i need a safe, boring way to get space back today and then a plan so this never happens again. pls help 🙏