Keep AI jobs alive during processing

internal/store/store.go

@@ -542,6 +542,24 @@ RETURNING ` + jobSelectColumns + `
 	return job, err
 }
 
+func (s *Store) HeartbeatJob(ctx context.Context, id uuid.UUID) error {
+	const q = `
+UPDATE ai_jobs
+SET heartbeat_at = NOW(),
+    updated_at = NOW()
+WHERE id = $1
+  AND status = 'running'
+`
+	tag, err := s.pool.Exec(ctx, q, id)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return nil
+	}
+	return nil
+}
+
 func (s *Store) FailJob(ctx context.Context, id uuid.UUID, in model.FailJob) (*model.Job, error) {
 	errorCode := strings.TrimSpace(in.ErrorCode)
 	if errorCode == "" {