In this Go repository (odin), fix backlog item B-071: `Advance` in internal/engine/engine.go has no default case in its switch on the node kind, so a graph node of a kind the engine does not know is skipped as if it had passed. Add a default case that stops the run with the `bad_manifest` reason, following how the engine already stops runs for other manifest problems. Add a test: a graph with a made-up node kind stops with bad_manifest. Run `GOWORK=off go test ./internal/engine/` and make sure it passes (the package's tests take about 90 seconds). Do not commit. Do not ask clarifying questions; make reasonable choices and say what you chose.
