- Convert LoginPage, RegisterPage, ProfilePage to FSD structure (index.ts + ui/)
- Convert PortfoliosListPage, PortfolioDetailPage to FSD structure
- Replace relative imports with @/ aliases in portfolio pages
- Add ESLint import/no-restricted-paths for FSD layer boundaries
- Refactor useSession test to mock context instead of import from app/
- Mark frontend-fsd-screener tasks as complete