feat(T01): auth + user management + RBAC + base frontend + i18n

- Backend: FastAPI, JWT auth (HS256), bcrypt, RBAC middleware
- User CRUD (admin-only), soft-delete, pagination
- Pydantic BaseSettings config, async SQLAlchemy 2.0
- 50 backend tests, 88% coverage
- Frontend: Next.js 14 App Router, Tailwind, design tokens
- Login page, auth context, API client with auto-refresh
- i18n: next-intl, DE/EN (31 keys each)
- 6 base UI components (Button, Input, Card, Table, Modal, Toast)
- 12 frontend tests, npm build success

backend/requirements.txt

@@ -0,0 +1,14 @@
+fastapi>=0.115.0
+uvicorn[standard]>=0.32.0
+sqlalchemy[asyncio]>=2.0.0
+asyncpg>=0.30.0
+pydantic-settings>=2.0.0
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+redis>=5.0.0
+python-multipart>=0.0.12
+pytest>=8.0.0
+pytest-asyncio>=0.24.0
+httpx>=0.27.0
+pytest-cov>=5.0.0
+aiosqlite>=0.20.0