- Remove structlog dependency from backend/pyproject.toml
- Add app.utils.logging_compat shim for keyword-arg logging API
- Add app.utils.json_formatter for JSON log output with extra fields
- Update all backend modules to use logging_compat.get_logger()
- Update docstrings in log_sanitizer.py and json_formatter.py
- Update test comment in test_async_utils.py
- Record 406 failing tests in Docs/Tasks.md for tracking
- Created StartupDAG class to orchestrate startup stages with explicit dependencies
- Defined 6 startup stages: WORKER_MODE → DATABASE → GEO_CACHE → HTTP_SESSION → SCHEDULER → TASKS
- Each stage has prerequisites, error handling, and rollback support
- Refactored startup_shared_resources() to use the DAG
- Added StartupContext for resource tracking and failure management
- Partial failures automatically roll back all completed resources in reverse order
- Added health checks to verify all resources initialized successfully
- Comprehensive test coverage: 15 DAG unit tests + 3 integration tests + 6 existing tests
- Documented startup DAG in Architekture.md with detailed stage descriptions and failure modes
This replaces implicit ordering with explicit dependency tracking, making lifecycle
changes safe and failure modes predictable. Hidden order dependencies no longer exist.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
