Talent lifecycle (21-day expiry) + noindex expired job/shift details

- Talent «آماده به کار» now has its own freshness window (21 days, vs 30
  for jobs) since availability goes stale fast; archiver, browse, and home
  use TalentCutoffUtc.
- Expired/filled job openings and past/filled shifts now emit
  robots noindex so Google drops dead listings instead of keeping
  soft-404 pages. (Talent details were already noindex.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/JobsMedical.Web/Services/Scraping/ListingArchiver.cs

@@ -14,7 +14,11 @@ public static class ListingPolicy
     /// <summary>A job opening older than this (since posting) is treated as stale and hidden.</summary>
     public const int JobFreshnessDays = 30;
 
+    /// <summary>«آماده به کار» goes stale faster — the person is usually hired within a few weeks.</summary>
+    public const int TalentFreshnessDays = 21;
+
     public static DateTime JobCutoffUtc => DateTime.UtcNow.AddDays(-JobFreshnessDays);
+    public static DateTime TalentCutoffUtc => DateTime.UtcNow.AddDays(-TalentFreshnessDays);
 }
 
 /// <summary>Sweeps stale listings into the Expired state (archive). Idempotent and cheap.</summary>
@@ -42,8 +46,9 @@ public class ListingArchiver
             .Where(j => j.Status == ShiftStatus.Open && j.CreatedAt < jobCutoff)
             .ExecuteUpdateAsync(u => u.SetProperty(j => j.Status, ShiftStatus.Expired), ct);
 
+        var talentCutoff = ListingPolicy.TalentCutoffUtc;
         var expiredTalent = await _db.TalentListings
-            .Where(t => t.Status == ShiftStatus.Open && t.CreatedAt < jobCutoff)
+            .Where(t => t.Status == ShiftStatus.Open && t.CreatedAt < talentCutoff)
             .ExecuteUpdateAsync(u => u.SetProperty(t => t.Status, ShiftStatus.Expired), ct);
 
         if (expiredShifts + expiredJobs + expiredTalent > 0)