🐛 fix(frontend): Playwright now detects health endpoint failures (was silently passing) (#32)

User caught silent regression: existing test only asserted dashboard visibility, which is also true on the error branch. New tests assert healthy state + new regression test mocks /api/healthz to 502.

Co-authored-by: Gabriel Radureau <arcodange@gmail.com>
Co-committed-by: Gabriel Radureau <arcodange@gmail.com>

frontend/components/HealthDashboard.stories.ts

@@ -6,11 +6,28 @@ const meta: Meta<typeof HealthDashboard> = {
   component: HealthDashboard,
   tags: ['autodocs'],
 }
-
 export default meta
 
 type Story = StoryObj<typeof meta>
 
+// Default story - calls real /api/healthz (works in browser if dev proxy + backend are up)
 export const Default: Story = {
   args: {},
 }
+
+// Documents the loading/error visuals so reviewers see them in Storybook
+// without needing a backend down. The component currently doesn't accept overrides
+// because it uses useFetch internally - this story is a placeholder for a future
+// refactor that exposes data/pending/error as props for testability.
+export const DocumentationStub: Story = {
+  args: {},
+  parameters: {
+    docs: {
+      description: {
+        story:
+          'Renders the same as Default. The HealthDashboard fetches /api/healthz internally, so loading/error states only appear when the backend is down or slow. ' +
+          'Future improvement: accept healthData/pending/error as props for easy state-based stories. Until then, see frontend/docs/e2e/ for screenshots of both healthy and error states.',
+      },
+    },
+  },
+}