test: refactor factory setup for coverage (#790)

* test: add git helper and guard annotations

* chore: align release metadata with 0.40.0

* test: refactor factory setup for coverage

cmd/bd/setup/setup_test_helpers.go

@@ -0,0 +1,22 @@
+package setup
+
+import "testing"
+
+type exitCapture struct {
+	called bool
+	code   int
+}
+
+func stubSetupExit(t *testing.T) *exitCapture {
+	t.Helper()
+	cap := &exitCapture{}
+	orig := setupExit
+	setupExit = func(code int) {
+		cap.called = true
+		cap.code = code
+	}
+	t.Cleanup(func() {
+		setupExit = orig
+	})
+	return cap
+}