Load plugins.username via importlib.util.spec_from_file_location
since plugins/ is not a Python package on sys.path.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
53 tests covering regex validation, service registry integrity,
classification logic (status/json/body), formatting, and category
grouping.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>