test(gsd): add zero-slice roadmap guided flow test

src/resources/extensions/gsd/tests/zero-slice-roadmap-guided.test.ts

@@ -0,0 +1,19 @@
+/**
+ * Regression test for #3441: guided flow must treat a roadmap with zero
+ * parseable slices the same as no roadmap — offer "Create roadmap" not "Go auto".
+ */
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+test("guided-flow checks roadmap slice count before offering auto (#3441)", () => {
+  const src = readFileSync(
+    join(import.meta.dirname, "..", "guided-flow.ts"),
+    "utf-8",
+  );
+  assert.ok(
+    src.includes("roadmapHasSlices") || src.includes("parseRoadmapSlices"),
+    "Guided flow must parse roadmap for slices before deciding which options to show",
+  );
+});