Dockerfile builds a static-web-server image serving src/ with the third-party
assets vendored in a first stage, so the runtime layer carries no Node and no
shell tooling. WITH_FFMPEG=0 drops the 18.5 MB asm.js encoder for a smaller
image, at the cost of fetching it at export time.
.gitignore covers dist/, which the release scripts write on every run: without
it a fresh clone reports the build output as untracked and publish.ps1 warns
that the worktree is dirty on every build.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
