Hide + archive stale listings (old jobs, expired shifts)

- ListingPolicy.JobFreshnessDays=30: public /Jobs and home hide jobs older than the cutoff (shifts already require Date>=today)
- ListingArchiver flips stale Open→Expired: shifts past their date, jobs older than the cutoff. Runs at startup and on every IngestionWorker cycle (independent of ingestion being enabled)
- Verified: backdated job dropped off /Jobs (6→5) and was archived to Expired on the sweep

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

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

@@ -28,6 +28,10 @@ public class IngestionWorker : BackgroundService
             try
             {
                 using var scope = _scopes.CreateScope();
+
+                // Always archive stale listings (independent of ingestion being on).
+                await scope.ServiceProvider.GetRequiredService<ListingArchiver>().ArchiveStaleAsync(stoppingToken);
+
                 var settings = await scope.ServiceProvider
                     .GetRequiredService<SettingsService>().GetAsync();
 

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

@@ -0,0 +1,49 @@
+using JobsMedical.Web.Data;
+using JobsMedical.Web.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace JobsMedical.Web.Services.Scraping;
+
+/// <summary>
+/// Centralizes "what counts as a live listing". Jobs have no end date, so they go stale after a
+/// window; shifts expire once their date has passed. Public screens hide anything outside these
+/// rules, and <see cref="ListingArchiver"/> flips stale Open rows to Expired so dashboards/DB agree.
+/// </summary>
+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;
+
+    public static DateTime JobCutoffUtc => DateTime.UtcNow.AddDays(-JobFreshnessDays);
+}
+
+/// <summary>Sweeps stale listings into the Expired state (archive). Idempotent and cheap.</summary>
+public class ListingArchiver
+{
+    private readonly AppDbContext _db;
+    private readonly ILogger<ListingArchiver> _log;
+
+    public ListingArchiver(AppDbContext db, ILogger<ListingArchiver> log)
+    {
+        _db = db;
+        _log = log;
+    }
+
+    public async Task<int> ArchiveStaleAsync(CancellationToken ct = default)
+    {
+        var today = DateOnly.FromDateTime(DateTime.UtcNow);
+        var jobCutoff = ListingPolicy.JobCutoffUtc;
+
+        var expiredShifts = await _db.Shifts
+            .Where(s => s.Status == ShiftStatus.Open && s.Date < today)
+            .ExecuteUpdateAsync(u => u.SetProperty(s => s.Status, ShiftStatus.Expired), ct);
+
+        var expiredJobs = await _db.JobOpenings
+            .Where(j => j.Status == ShiftStatus.Open && j.CreatedAt < jobCutoff)
+            .ExecuteUpdateAsync(u => u.SetProperty(j => j.Status, ShiftStatus.Expired), ct);
+
+        if (expiredShifts + expiredJobs > 0)
+            _log.LogInformation("Archived {Shifts} shifts + {Jobs} jobs as expired", expiredShifts, expiredJobs);
+        return expiredShifts + expiredJobs;
+    }
+}