fix(core): handle partial listing data

packages/core/test/kijiji-integration.test.ts

@@ -13,7 +13,7 @@ describe("HTML Parsing Integration", () => {
     // Mock fetch for all tests
     global.fetch = mock(() => {
       throw new Error("fetch should be mocked in individual tests");
-    });
+    }) as unknown as typeof fetch;
   });
 
   afterEach(() => {
@@ -111,7 +111,7 @@ describe("HTML Parsing Integration", () => {
 			`;
 
       const results = parseSearch(mockHtml, "https://www.kijiji.ca");
-      expect(results[0].listingLink).toBe(
+      expect(results[0]?.listingLink).toBe(
         "https://www.kijiji.ca/v-iphone/k0l0",
       );
     });
@@ -146,7 +146,7 @@ describe("HTML Parsing Integration", () => {
 
       const results = parseSearch(mockHtml, "https://www.kijiji.ca");
       expect(results).toHaveLength(1);
-      expect(results[0].name).toBe("iPhone 13 Pro");
+      expect(results[0]?.name).toBe("iPhone 13 Pro");
     });
 
     test("should return empty array for invalid HTML", () => {