feat(api): Protokollzeile je Anfrage und je Nextcloud-Pruefung im Docker-Log

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/api/src/nextcloud-status/nextcloud-status-scheduler.service.ts

@@ -146,6 +146,8 @@ export class NextcloudStatusSchedulerService implements OnApplicationBootstrap {
     for (const [tenantId, ids] of byTenant) {
       for (const id of ids) work.push({ tenantId, id });
     }
+    if (work.length === 0) return;
+    const startedAt = Date.now();
     await runWithConcurrency(work, CHECK_CONCURRENCY, async ({ tenantId, id }) => {
       try {
         await this.service.checkInstance(tenantId, id);
@@ -155,5 +157,8 @@ export class NextcloudStatusSchedulerService implements OnApplicationBootstrap {
         );
       }
     });
+    this.logger.log(
+      `Nextcloud-Pruefdurchlauf: ${work.length} Cloud(s) in ${Date.now() - startedAt} ms`,
+    );
   }
 }