Knowledge base: progress is proven over the bus with the module started whole (issue 1947)

The verb asks three seats and the records module; only a run over a real bus shows its
grants and subjects line up with what the manifest invokes.

modules/mesh-knowledge/cmd/mesh-knowledge/progress_test.go

@@ -18,6 +18,28 @@ func progressRecords() dirRecords {
 	return dirRecords{dir: filepath.Join("testdata", "progress", "hq")}
 }
 
+// withDesigns is the fixture's records with the captured designs beside them, as the bus test's records module
+// serves them: a folder or document the first does not hold is read from the second.
+type withDesigns struct{ base, designs dirRecords }
+
+func (w withDesigns) Standing() (string, error) { return w.base.Standing() }
+
+func (w withDesigns) List(folder string) ([]string, []string, error) {
+	if f, d, err := w.base.List(folder); err == nil {
+		return f, d, nil
+	}
+	return w.designs.List(folder)
+}
+
+func (w withDesigns) Read(path string) (string, string, error) {
+	if c, commit, err := w.base.Read(path); err == nil {
+		return c, commit, nil
+	}
+	c, _, err := w.designs.Read(path)
+	commit, _ := w.base.Standing()
+	return c, commit, err
+}
+
 // seatsWorld plays the issue tracker and mesh-delivery from the captured answers, and counts what it is asked.
 type seatsWorld struct {
 	mu     sync.Mutex