fix: close marketplace client review findings

tests/unit/host-api.test.ts

@@ -141,6 +141,32 @@ describe('host-api', () => {
     );
   });
 
+  it('preserves a bounded Marketplace status through browser fallback', async () => {
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 409,
+      statusText: 'Conflict',
+      json: async () => ({
+        success: false,
+        code: 'plugin_release_yanked',
+        error: 'Release is no longer available',
+      }),
+    });
+    vi.stubGlobal('fetch', fetchMock);
+    window.localStorage.setItem('niancode:allow-localhost-fallback', '1');
+    invokeIpcMock.mockResolvedValueOnce({
+      ok: false,
+      error: { message: 'No handler registered for hostapi:fetch' },
+    });
+
+    const { hostApiFetch } = await import('@/lib/host-api');
+    await expect(hostApiFetch('/api/coding/plugin-marketplace/install/notes'))
+      .rejects.toMatchObject({
+        message: 'Release is no longer available',
+        details: { backendCode: 'plugin_release_yanked', status: 409 },
+      });
+  });
+
   it('throws message from legacy non-ok envelope', async () => {
     invokeIpcMock.mockResolvedValueOnce({
       success: true,