Adds Dockerfile.android (Flutter + Android SDK/JDK 17) and
Dockerfile.linux (Flutter + clang/cmake/GTK3 for desktop builds).
Publish and Scout pipelines now use matrix strategy to build all
three variants in parallel. Registry secrets updated to
REGISTRY_USERNAME/REGISTRY_PASSWORD. Update-check adds explicit
stable channel filter.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Dockerfile based on debian:bookworm-slim with web-only Flutter SDK
- Release pipeline with Docker Scout CVE scan, SBOM, and provenance
- Scout PR pipeline with check-image gate
- Daily update-check pipeline that auto-creates releases for new
Flutter stable versions via Gitea API
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>