Ruuvi Firmware version 3. Built on top of Nordic SDK 15, uses both Ruuvi and external repositories as submodules. In Beta, no breaking changes are intended but may be done if absolutely necessary
This would be possible with containerized build, e.g. with Docker. However, as tags are not so security critical implementing this would be more of an academic exercise than actually needed feature
Users should be able to check their app .apk against automated builds, similar to https://core.telegram.org/reproducible-builds