Adds role_tag_problems() to check-tags.py: every role imported in a
play's roles: block must carry its own role name as a tag (extra tags
allowed; templated role names skipped). Wires the check into main() so
make lint catches violations. 6 new unit tests (29 total, all passing).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
