Deprecations

Probably a good place to start for any modernization:
```
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
npm WARN deprecated har-validator@5.1.5: this library is no longer supported
npm WARN deprecated uuid@3.4.0: Please upgrade to version 7 or higher. Older versions may use Math.random() in certain circumstances, which is known to be problematic. See https://v8.dev/blog/math-random for details.
```

The issue only provides npm deprecation warnings, with no files, tests, or specific replacement scope named. Start by running the project’s npm installation and tracing which dependencies bring in request, har-validator, and uuid. Done should mean the deprecated packages are resolved without breaking the ActivityPub server, but the issue needs a maintainer-defined target and verification steps.

Written by the indexing model from the issue text.