Refactor recommendation response handling and enhance enrichment logic

- Removed the `buildRecommendedTenderResponsesParallel` method and replaced it with `buildRecommendedTenderListResponses`, simplifying the response building process.
- Introduced `enrichRecommendedTenderResponsesParallel` to handle enrichment of tender responses in parallel, improving performance.
- Updated the `Recommend` method to utilize the new enrichment logic, ensuring timely and efficient processing of recommendations.
- Cleaned up unused functions and imports in `recommendation_page_cache.go` and `recommendation_response.go`, enhancing code clarity and maintainability.

This update streamlines the recommendation response handling and improves the overall efficiency of the tender recommendation service.

internal/tender/service.go

@@ -96,8 +96,9 @@ type tenderService struct {
 }
 
 const (
-	aiSummaryEnrichmentTimeout     = 2 * time.Second
-	aiTranslationEnrichmentTimeout = 2 * time.Second
+	aiSummaryEnrichmentTimeout        = 2 * time.Second
+	aiTranslationEnrichmentTimeout    = 2 * time.Second
+	recommendTranslationEnrichmentTimeout = 5 * time.Second
 )
 
 var (
@@ -214,6 +215,17 @@ func (s *tenderService) enrichWithAISummary(ctx context.Context, t *Tender, resp
 // enrichWithTranslation overlays title/description from MinIO when the pipeline has finished
 // for the requested language. Does not call the AI translate API on GET.
 func (s *tenderService) enrichWithTranslation(ctx context.Context, t *Tender, resp *TenderResponse, language string, cache *recommendationTranslationCache) {
+	s.enrichWithTranslationTimeout(ctx, t, resp, language, cache, aiTranslationEnrichmentTimeout)
+}
+
+func (s *tenderService) enrichWithTranslationTimeout(
+	ctx context.Context,
+	t *Tender,
+	resp *TenderResponse,
+	language string,
+	cache *recommendationTranslationCache,
+	enrichmentTimeout time.Duration,
+) {
 	if t == nil || resp == nil {
 		return
 	}
@@ -233,7 +245,7 @@ func (s *tenderService) enrichWithTranslation(ctx context.Context, t *Tender, re
 		}
 	}
 
-	enrichCtx, cancel := context.WithTimeout(ctx, aiTranslationEnrichmentTimeout)
+	enrichCtx, cancel := context.WithTimeout(ctx, enrichmentTimeout)
 	defer cancel()
 
 	stored, usedNotice, err := s.lookupTranslationForTender(enrichCtx, t, targetLanguage)
@@ -1027,7 +1039,8 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 		return nil, err
 	}
 
-	paged := s.buildRecommendedTenderResponsesParallel(ctx, pageResult.items, lang)
+	paged := s.buildRecommendedTenderListResponses(pageResult.items, lang)
+	paged = s.enrichRecommendedTenderResponsesParallel(ctx, paged, lang)
 
 	return &SearchResponse{
 		Tenders:  paged,