refactor(server): correct stale org wording in messages

server/internal/services/instances.go

@@ -92,7 +92,7 @@ func AdoptInstance(instanceID, name string) (*models.Instance, error) {
 
 	if _, err := db.Col("instances").UpdateOne(ctx, bson.M{"instance_id": instanceID}, bson.M{"$set": set}); err != nil {
 		if mongo.IsDuplicateKeyError(err) {
-			return nil, fmt.Errorf("organization slug already taken")
+			return nil, fmt.Errorf("instance slug already taken")
 		}
 		return nil, err
 	}

server/internal/services/monitors.go

@@ -52,7 +52,7 @@ func ListMonitors(instanceID string) ([]models.Monitor, error) {
 
 func ListMonitorsForRunner(instanceID, runner string) ([]models.Monitor, error) {
 	if instanceID == "" {
-		return nil, errors.New("org id required")
+		return nil, errors.New("instance id required")
 	}
 	return listMonitorsForRunner(instanceID, runner)
 }
@@ -227,7 +227,7 @@ func UptimeRollups(instanceID, monitorID string, since time.Time) ([]models.Roll
 
 func IngestResult(instanceID, runner, monitorID string, res checker.Result) error {
 	if instanceID == "" {
-		return errors.New("org id required")
+		return errors.New("instance id required")
 	}
 	return ingestResult(instanceID, runner, monitorID, res)
 }