- Version parsing and comparison tests
- Cache management with TTL validation
- API fetching with network error handling
- Check for updates (with caching)
- Download update with checksum file handling
- Checksum verification (match/mismatch/missing)
- Platform-aware installer launching (Windows MSI, macOS DMG)
- All 20 tests passing with proper async/await support
- Installed pytest-asyncio for async test support
- Updated copilot instructions to document .venv environment
