perf(scheduler): harden jobs for scalable execution

server/internal/ops/repository/scheduler.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"time"
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
@@ -188,6 +189,25 @@ func (r *SchedulerRepository) GetJobForRuntime(ctx context.Context, key string)
 		WHERE j.job_key = $1`, key))
 }
 
+func (r *SchedulerRepository) LastAutoRunStartedAt(ctx context.Context, key string) (time.Time, bool, error) {
+	var startedAt time.Time
+	err := r.pool.QueryRow(ctx, `
+		SELECT started_at
+		FROM ops.scheduler_job_runs
+		WHERE job_key = $1
+		  AND trigger_type = 'auto'
+		ORDER BY started_at DESC, id DESC
+		LIMIT 1
+	`, key).Scan(&startedAt)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return time.Time{}, false, nil
+		}
+		return time.Time{}, false, err
+	}
+	return startedAt, true, nil
+}
+
 func (r *SchedulerRepository) UpdateJob(ctx context.Context, key string, in SchedulerJobUpdate) (*domain.SchedulerJob, error) {
 	configJSON, err := marshalSchedulerJSONMap(in.Config)
 	if err != nil {