Every served bundle is its own process now, so each carries its own copy of what it imports: after
the compile and the launchers, the toolchain image's esbuild bundles every entrypoint in place and
every launcher under its own name into one ES module file, the SDK inlined, require provided to
inlined CommonJS, the launcher's shebang kept and its mode 0755. The toolchain's node_modules is
copied only for packages an artifact names external. An image without the bundler is refused by
name. Issue 212: build.on already passes a published package by its exact version and plans the
toolchain after it; tests say so.