feat(backend/jobs): add agent_id parameter

backend/internal/repository/job_repository.go

@@ -113,18 +113,22 @@ type JobMetrics struct {
 }
 
 // GetJobMetrics returns job success metrics for jobs updated since the given time.
-// A successful job has status == 0, failed has status != 0, pending has status == 0 with empty stdout/stderr.
-func (r *JobRepository) GetJobMetrics(ctx context.Context, since time.Time) (JobMetrics, error) {
+// If agentID is non-empty, results are filtered to that agent only.
+func (r *JobRepository) GetJobMetrics(ctx context.Context, since time.Time, agentID string) (JobMetrics, error) {
 	var m JobMetrics
-	err := r.DB.QueryRowContext(ctx,
-		`SELECT
-			COUNT(*),
-			SUM(CASE WHEN status = 0 AND (stdout != '' OR stderr != '') THEN 1 ELSE 0 END),
-			SUM(CASE WHEN status != 0 THEN 1 ELSE 0 END),
-			SUM(CASE WHEN status = 0 AND stdout = '' AND stderr = '' THEN 1 ELSE 0 END)
-		FROM jobs WHERE updated_at >= ?`,
-		since,
-	).Scan(&m.Total, &m.Success, &m.Failed, &m.Pending)
+	query := `SELECT
+		COUNT(*),
+		SUM(CASE WHEN status = 0 AND (stdout != '' OR stderr != '') THEN 1 ELSE 0 END),
+		SUM(CASE WHEN status != 0 THEN 1 ELSE 0 END),
+		SUM(CASE WHEN status = 0 AND stdout = '' AND stderr = '' THEN 1 ELSE 0 END)
+	FROM jobs WHERE updated_at >= ?`
+	args := []any{since}
+	if agentID != "" {
+		query += " AND agent_id = ?"
+		args = append(args, agentID)
+	}
+
+	err := r.DB.QueryRowContext(ctx, query, args...).Scan(&m.Total, &m.Success, &m.Failed, &m.Pending)
 	if err != nil {
 		return JobMetrics{}, err
 	}