fix(features): address Task 3 code review feedback

- 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>

packages/navigation/src/__factories__/index.ts

@@ -1 +1,2 @@
 export { headerFactory } from "./header.factory.js";
+export { navItemFactory } from "./nav-item.factory.js";