The toolchain image installs from this package.json with a range; unchanged, Docker reused the
cached install and the image kept SDK 0.1.3 after 0.1.5 was published. Bundles copied that copy, so
a launched bundle registering its seat first served the seat's verbs as its own tools. Requiring
0.1.5 says what the runtime and its bundles need, and invalidates the cached layer.