Add initial niaeve implementation of SFTP logging

This will end up flooding the activity logs due to the way SFTP works, we'll need to have an intermediate step in Wings that batches events every 10 seconds or so and submits them as a single "event" for activity.

internal/cron/activity_cron.go

@@ -18,6 +18,7 @@ func processActivityLogs(m *server.Manager, c int64) error {
 	// Don't execute this cron if there is currently one running. Once this task is completed
 	// go ahead and mark it as no longer running.
 	if !processing.SwapIf(true) {
+		log.WithField("subsystem", "cron").Warn("cron: process overlap detected, skipping this run")
 		return nil
 	}
 	defer processing.Store(false)

internal/cron/cron.go

@@ -26,7 +26,7 @@ func Scheduler(m *server.Manager) (*gocron.Scheduler, error) {
 	}
 
 	s := gocron.NewScheduler(l)
-	_, _ = s.Tag("activity").Every(config.Get().System.ActivitySendInterval).Seconds().Do(func() {
+	_, _ = s.Tag("activity").Every(int(config.Get().System.ActivitySendInterval)).Seconds().Do(func() {
 		if err := processActivityLogs(m, config.Get().System.ActivitySendCount); err != nil {
 			log.WithField("error", err).Error("cron: failed to process activity events")
 		}