- Add ruff as dev dependency
- Configure ruff in pyproject.toml with strict 88-char line limit
- Ignore B008 (FastAPI Depends pattern is standard)
- Allow longer lines in tests for readability
- Fix all lint issues in source files
- Add Makefile targets: lint-backend, format-backend, fix-backend
- Changed formatTime back to use toLocaleTimeString (local time)
- Changed formatDateTime back to use toLocaleString (local time)
- App now displays all times in user's local timezone
- Backend still stores times in UTC, frontend converts for display