fix(qajobsboard): drop expired LinkedIn reposts and resolve hiring location

Probe application links for closed listings and feed expires_at; enrich vague Remote/Worldwide rows with real country before blocked-countries filtering.

Co-authored-by: Cursor <cursoragent@cursor.com>

extractors/qajobsboard/tests/detail-page.test.ts

@@ -23,6 +23,13 @@ describe("parseQaJobDetailPage", () => {
     expect(result?.jobDescription).toContain("Mumbai/Nagpur");
   });
 
+  it("marks posting expired when validThrough is in the past", () => {
+    const html = `<script type="application/ld+json">
+{"@type":"JobPosting","validThrough":"2020-01-01","title":"Old role"}
+</script>`;
+    expect(parseQaJobDetailPage(html)).toEqual({ expired: true });
+  });
+
   it("extracts job location lines from plain text", () => {
     expect(
       extractJobLocationFromText(