test(frontend): add Storybook coverage for WorkspaceNav

frontend/src/components/WorkspaceNav.stories.tsx

@@ -0,0 +1,34 @@
+import type { Meta, StoryObj } from "@storybook/react-vite";
+import { WorkspaceNav } from "./WorkspaceNav";
+
+const meta = {
+  title: "Navigation/WorkspaceNav",
+  component: WorkspaceNav,
+  args: {
+    destination: "board",
+    onChange: () => undefined,
+  },
+} satisfies Meta<typeof WorkspaceNav>;
+
+export default meta;
+
+type Story = StoryObj<typeof meta>;
+
+export const Board: Story = {};
+
+export const AskAgent: Story = {
+  args: { destination: "ask" },
+};
+
+export const Admin: Story = {
+  args: { destination: "admin" },
+};
+
+// Edge case: an extra tools slot (e.g. a settings or logout control) rendered
+// alongside the nav items.
+export const WithTools: Story = {
+  args: {
+    destination: "customers",
+    tools: <button type="button">Sign out</button>,
+  },
+};