- Add navItemFactory to navigation (spec §5.1 — was missing)
- Refactor blog/router.test.ts to use articleFactory (eliminate new Date())
- headerFactory uses sequence for logoId (deterministic buildList output)
- Align media/tsconfig.json with other features (jsx + tests/ include)
- Refactor auth/container.test.ts to use userFactory
Reviewer: superpowers:code-reviewer (Task 3 of Plan 7).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds src/__factories__/<entity>.factory.ts to auth, blog, marketing-pages,
navigation, media. Each factory uses defineFactory from @repo/core-testing
with stable date defaults (2026-01-01) so snapshot diffs reflect SUT
behavior only. Refactors mechanical inline-fixture tests to use factories.
Also adds vitest.config.ts and tsconfig path alias to @repo/media (lacked
both), and adds @repo/core-testing devDependency to @repo/media.
Spec: §5.1, §6.3
