feat(transport): register AddTransport() on central nodes

src/ScadaLink.Host/Program.cs

@@ -19,6 +19,7 @@ using ScadaLink.NotificationService;
 using ScadaLink.Security;
 using ScadaLink.SiteCallAudit;
 using ScadaLink.TemplateEngine;
+using ScadaLink.Transport;
 using Serilog;
 
 // SCADALINK_CONFIG determines which role-specific config to load (Central or Site)
@@ -80,6 +81,10 @@ try
         // AddNotificationService() SMTP machinery above. AddNotificationOutbox binds
         // NotificationOutboxOptions via BindConfiguration, so no explicit Configure is needed.
         builder.Services.AddNotificationOutbox();
+        // Transport (#24) — central-only bundle export/import pipeline. Binds
+        // TransportOptions from ScadaLink:Transport via BindConfiguration; no
+        // explicit Configure needed.
+        builder.Services.AddTransport();
         // Audit Log (#23) — central node owns the AuditLogIngestActor singleton +
         // IAuditLogRepository. The site writer chain is still registered (lazy
         // singletons) but is never resolved on a central node.