prod: UI Optimisée mise en production

- Documentation archivée et réorganisée
- Backend: Ajout tests, migrations, library service, rate limiting
- Frontend: Suppression Flutter, focus sur interface web HTML/JS
- Tailwind CSS ajouté pour le style
- Améliorations UX et corrections bugs

Generated with [Claude Code](https://claude.com/claude-code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

backend/pytest.ini

@@ -0,0 +1,7 @@
+[pytest]
+asyncio_mode = auto
+asyncio_default_fixture_loop_scope = function
+testpaths = tests
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*