1.0.0

This is an AI-assisted release to include several minor speed improvements and tests.

• Optimise key generation by reusing buffers to reduce heap allocations
• Add comprehensive unit tests for key generation and utility functions
• Add GitHub Actions workflow for automated testing on push and pull requests
• Update Go to 1.25.0
• Add -v / --version flag to display current version and check for updates
• Add -u / --update flag to self-update to the latest release