feat: add public listing detail web flow

apps/web/tests/catalog-service.test.js

@@ -1,6 +1,18 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 
-test('web workspace exposes a catalog test entrypoint', () => {
-  assert.ok(true);
+import { getPublicListing } from '../src/services/catalog-service.js';
+
+test('fetches a public listing detail through the API service', async () => {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async (url) => {
+    assert.equal(url, 'http://localhost:3000/api/v1/public/listings/listing-1');
+    return { ok: true, async json() { return { data: { id: 'listing-1' } }; } };
+  };
+
+  try {
+    assert.deepEqual(await getPublicListing('listing-1'), { id: 'listing-1' });
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
 });