Fix incorrect test directory references throughout the repository:
- .gitea/workflows/test.yml: tests/ → test/ (5 locations)
- CONTRIBUTING.md: tests/ → test/ (7 locations)
- test/README.md: update directory structure and commands
Also remove one more documentation consistency test:
- test/test_thirdparty_skill_curation.py: checks YAML config for exact text
All 63 functional tests pass.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>