Rewrite search flow and enrich preview assets

backend/handlers/api.go

@@ -280,7 +280,11 @@ func (a *App) searchMedia(c *gin.Context) {
 	}
 
 	a.Hub.Broadcast("progress", gin.H{"type": "search", "status": "ranking thumbnail candidates", "progress": 55})
-	scored := rankSearchResults(req.Query, results)
+	rankQuery := req.Query
+	if len(queryVariants) > 0 {
+		rankQuery = strings.Join(queryVariants[:min(len(queryVariants), 3)], " ")
+	}
+	scored := rankSearchResults(rankQuery, results)
 	shortlist := scored[:min(len(scored), 10)]
 	a.Hub.Broadcast("progress", gin.H{"type": "search", "status": "analyzing shortlisted thumbnails with Gemini Vision", "progress": 75})
 	recommended, err := a.GeminiService.Recommend(req.Query, shortlist)
@@ -288,12 +292,13 @@ func (a *App) searchMedia(c *gin.Context) {
 		fallback := make([]services.AIRecommendation, 0, min(20, len(scored)))
 		for _, result := range scored[:min(20, len(scored))] {
 			fallback = append(fallback, services.AIRecommendation{
-				Title:        result.Title,
-				Link:         result.Link,
-				ThumbnailURL: result.ThumbnailURL,
-				Source:       result.Source,
-				Reason:       "Keyword-ranked result added without extra Gemini vision tokens.",
-				Recommended:  true,
+				Title:           result.Title,
+				Link:            result.Link,
+				ThumbnailURL:    result.ThumbnailURL,
+				PreviewVideoURL: result.PreviewVideoURL,
+				Source:          result.Source,
+				Reason:          "Keyword-ranked result added without extra Gemini vision tokens.",
+				Recommended:     true,
 			})
 		}
 		warning := err.Error()
@@ -379,9 +384,12 @@ func rankSearchResults(query string, results []services.SearchResult) []services
 		if result.ThumbnailURL != "" {
 			score += 2
 		}
+		if result.PreviewVideoURL != "" {
+			score += 3
+		}
 		switch result.Source {
 		case "Google Video":
-			score += 1
+			score -= 1
 		case "Envato":
 			score += 7
 		case "Artgrid":
@@ -419,12 +427,13 @@ func mergeRecommendations(recommended []services.AIRecommendation, ranked []serv
 		}
 		seen[item.Link] = true
 		merged = append(merged, services.AIRecommendation{
-			Title:        item.Title,
-			Link:         item.Link,
-			ThumbnailURL: item.ThumbnailURL,
-			Source:       item.Source,
-			Reason:       "Keyword-ranked result added without extra Gemini vision tokens.",
-			Recommended:  true,
+			Title:           item.Title,
+			Link:            item.Link,
+			ThumbnailURL:    item.ThumbnailURL,
+			PreviewVideoURL: item.PreviewVideoURL,
+			Source:          item.Source,
+			Reason:          "Keyword-ranked result added without extra Gemini vision tokens.",
+			Recommended:     true,
 		})
 	}
 	return merged