fix: /demos/[vertical] route with Next.js 15 params await

- Fix Next.js 15 params requirement (await params)
- Add minimal test for route redirect behavior
- Test verifies all 4 verticals redirect correctly

tests/demos-vertical.test.ts

@@ -0,0 +1,53 @@
+/**
+ * Simple test for /demos/[vertical] route
+ * Tests that the dynamic route properly handles vertical params and redirects
+ */
+
+const VERTICALS = ['restaurant', 'real-estate', 'clinic', 'car-rental'];
+
+const BASE_URL = process.env.TEST_BASE_URL || 'http://localhost:1284';
+
+async function testRoute(vertical) {
+  const response = await fetch(`${BASE_URL}/demos/${vertical}`, {
+    redirect: 'manual' // Don't follow redirect, just get the location
+  });
+  
+  // Should return a 307 redirect (temporary redirect in Next.js)
+  if (response.status !== 307 && response.status !== 302) {
+    throw new Error(`Expected 307/302 for /demos/${vertical}, got ${response.status}`);
+  }
+  
+  // Should redirect to /demos?vertical=<vertical>
+  const location = response.headers.get('location');
+  if (!location || !location.includes(`/demos?vertical=${vertical}`)) {
+    throw new Error(`Expected redirect to /demos?vertical=${vertical}, got ${location}`);
+  }
+  
+  console.log(`✓ /demos/${vertical} redirects to ${location}`);
+  return true;
+}
+
+async function runTests() {
+  console.log('Testing /demos/[vertical] route...\n');
+  
+  let passed = 0;
+  let failed = 0;
+  
+  for (const vertical of VERTICALS) {
+    try {
+      await testRoute(vertical);
+      passed++;
+    } catch (error) {
+      console.error(`✗ /demos/${vertical} failed: ${error.message}`);
+      failed++;
+    }
+  }
+  
+  console.log(`\nResults: ${passed} passed, ${failed} failed`);
+  
+  if (failed > 0) {
+    process.exit(1);
+  }
+}
+
+runTests();