All tests are registrar-actor integration scenarios
sharing intertwined helpers + `enable_modules=[__name__]`
task fns, so keep as one mod but rename to reflect
content. Now lives alongside `test_multiaddr.py` in
the new `tests/discovery/` subpkg.
Also,
- update 5 refs in `/run-tests` SKILL.md to match
the new path
- add `discovery/` subdir to the test directory
layout tree
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi