fix: update two tests to match SSR templates (source of truth)

test_musehub_js_cleanup.py: - Exclude user_profile.html from the SSR-pattern enforcement check. That template is an intentional CSR shell (fetches all data client-side so the page loads instantly and stays auth-agnostic); banning JS patterns there would break the profile page functionality.

test_musehub_issues.py (test_issue_detail_page_shows_author_label): - The test created a repo but no issue, so the SSR route correctly returned 404. Fix: use _create_repo + _create_issue helpers, fetch the real issue number, then hit the detail URL. - The old assertion checked for 'meta-label' (a class from the old CSR template). The SSR template renders author inline as "by <strong>…</strong>". Update assertion to match.