Changelog
Changes are recorded in CHANGELOG.md in the repository (in Japanese).
Firmware for each release (full image and application-only image) is available on GitHub Releases. The Web Flasher installs the latest release.
Version numbers follow Semantic Versioning. The major version is raised for incompatible changes to the config.json format or a change of the target hardware. Versions stay at 0.x until the requirements are settled.