refactor(jobs): modularize background job handlers

Tiku.Infrastructure/Tenancy/TenantDomainRecheckJobHandler.cs

@@ -0,0 +1,19 @@
+using System.Text.Json;
+using Tiku.Application.Jobs;
+using Tiku.Application.Tenancy;
+
+namespace Tiku.Infrastructure.Tenancy;
+
+internal sealed class TenantDomainRecheckJobHandler(ITenantDomainLifecycleService lifecycleService)
+    : IBackgroundJobHandler
+{
+    public string JobType => "tenant_domain_recheck";
+
+    public async Task<BackgroundJobHandlerResult> HandleAsync(
+        BackgroundJobExecutionContext context,
+        CancellationToken cancellationToken = default)
+    {
+        var processed = await lifecycleService.ProcessPendingAsync(cancellationToken);
+        return new BackgroundJobHandlerResult(JsonSerializer.SerializeToElement(new { processed }));
+    }
+}