route-proxy's own Dockerfile documents the shape it has always needed and
never had: 'the proxy source is not vendored here... the build context is
the mesh-controller repository root, and this Dockerfile compiles
./examples/route-proxy from it.' Nothing in the mesh could do that — the
build command clones one repository and builds every artifact from
within it, so route-proxy has never once been built through the pipeline,
consistent with it never having been assigned anywhere. Found attempting
exactly that build tonight: 'stat go.mod: file does not exist', because
the context was mesh-catalog, which does not have one.
An image artifact may now carry a context: {repository, ref}, cloned
fresh alongside the module's own tree. The recipe (Dockerfile) is still
read from the module's own directory, at the module's own commit — only
docker build's own context argument moves. Packaging and source stay
exactly as separate as route-proxy's own comment already said they were,
now for real.