Backfill partial Gemini results and restore modal iframe

backend/handlers/api.go

@@ -458,6 +458,14 @@ func (a *App) searchMedia(c *gin.Context) {
 	}
 
 	merged := services.MergeRecommendations(recommended, scored, 20)
+	if geminiErr != nil {
+		merged = services.BackfillRecommendations(
+			merged,
+			scored,
+			12,
+			"Gemini 배치 일부가 실패해 미리보기 가능한 상위 후보를 보강했습니다.",
+		)
+	}
 	merged = services.RandomizeTopRecommendations(merged, 8)
 	warning := ""
 	if geminiErr != nil {

backend/services/ranker.go

@@ -355,6 +355,38 @@ func MergeRecommendations(recommended []AIRecommendation, ranked []SearchResult,
 	return merged
 }
 
+func BackfillRecommendations(existing []AIRecommendation, ranked []SearchResult, limit int, reason string) []AIRecommendation {
+	merged := make([]AIRecommendation, 0, min(limit, len(ranked)))
+	seen := map[string]bool{}
+	for _, item := range existing {
+		if item.Link == "" || seen[item.Link] {
+			continue
+		}
+		seen[item.Link] = true
+		merged = append(merged, item)
+	}
+	for _, item := range ranked {
+		if len(merged) >= limit || item.Link == "" || seen[item.Link] {
+			continue
+		}
+		if strings.TrimSpace(item.ThumbnailURL) == "" && strings.TrimSpace(item.PreviewVideoURL) == "" {
+			continue
+		}
+		seen[item.Link] = true
+		merged = append(merged, AIRecommendation{
+			Title:           item.Title,
+			Link:            item.Link,
+			Snippet:         item.Snippet,
+			ThumbnailURL:    item.ThumbnailURL,
+			PreviewVideoURL: item.PreviewVideoURL,
+			Source:          item.Source,
+			Reason:          reason,
+			Recommended:     false,
+		})
+	}
+	return merged
+}
+
 func max(a, b int) int {
 	if a > b {
 		return a