One way to do this is to use the Archive list - when you need a report, you go to Archive and press Archive all. Then at the top of the list you will see the actions completed this week sorted by descending completion date. You can also export this list into plain text with the “Copy view as text” button in the filter section above.
Another option I would suggest for this and other reporting use cases is writing a sqlite3 script against the database directly Export data on command line. It will be really simple and flexible, better than anything that can realistically be done in-app.
We should probably have a section on the website that shows some examples of using sqlite to generate reports.
As the app feature, the reports of this kind would definitely be useful, but I think not as useful as many of the other pending features.