Draw a plan's order per module from the graph and the manifests' change, and read no after: line (issue 977, part B, ADR 0419)

cmd/mesh-controller/batches_test.go

@@ -19,7 +19,15 @@ import (
 // The suite's tests of a merge, but for the merge window's own (this file's), plan the merge as it is heard: a
 // window of nothing closes at once, so a merge with no walk open is cut into its walk at once, as every merge
 // was planned before novox/hq ADR 0276. The window's tests set it through the controller's settings.
-func init() { mergeWindowDefault = 0 }
+func init() {
+	mergeWindowDefault = 0
+	// No forge in a test: no manifest is found at any commit, so a merge draws no edge of the manifests' change
+	// (delivery_edges.go). A test that wants some replaces these (forgeHolding).
+	manifestAt = func(context.Context, string, string, string, string) (catalogue.Manifest, bool, error) {
+		return catalogue.Manifest{}, false, nil
+	}
+	parentOf = func(context.Context, string, string, string) (string, error) { return "", nil }
+}
 
 // windowed is a mesh whose controller's settings give a merge window of 90 seconds and at most 10 minutes, as its
 // settings file says them, and