Merge upstream: Mantine v7, document edit times, minor fixes and upgrades
Contains the following upstream changes from master:
- Improving the container/Dockerfile setup
- Sort documents lexicographically in the frontend when like counts are the same
- Fix changing exam category blanking the page
- Better handling of the "default" category: prevent renames, move documents to it when parent category deleted, etc
- Fix newlines in answers being ignored because span is used instead of p
- Add document last update times
- Limit maximum exam PDF size to 2.5 mb
- Migrate from Mantine v6 to v7, removing
vseth-canine-uidependency - Some other small minor version upgrades in dependencies
The Mantine migration specifically changes almost all frontend files, so a lot of manual merges had to be performed.