Improve Vertex search result extraction

backend/handlers/api.go

@@ -263,6 +263,10 @@ func (a *App) searchMedia(c *gin.Context) {
 		c.JSON(http.StatusBadGateway, gin.H{"error": err.Error()})
 		return
 	}
+	if len(results) == 0 {
+		c.JSON(http.StatusOK, gin.H{"results": []services.AIRecommendation{}, "warning": "Vertex AI Search returned no renderable results. Check your website indexing fields and thumbnails."})
+		return
+	}
 
 	recommended, err := a.GeminiService.Recommend(req.Query, results)
 	if err != nil {