Improve modal fit and Gemini search refinement

backend/handlers/api.go

@@ -467,7 +467,7 @@ func (a *App) searchMedia(c *gin.Context) {
 	supplementalDeadlineLimited := false
 	if services.NeedsSupplementalExploration(recommended) && time.Now().Before(deadline.Add(-10*time.Second)) {
 		a.Hub.Broadcast("progress", gin.H{"type": "search", "status": "Gemini 평가가 약해 추가 후보를 탐색하는 중", "progress": 82})
-		explorationQueries := buildSupplementalQueries(req.Query, queryVariants)
+		explorationQueries := buildSupplementalQueries(a.GeminiService, req.Query, queryVariants, recommended)
 		extraResults, extraMeta, extraErr := a.SearchService.SearchMediaWithDeadline(explorationQueries, enabledPlatforms, deadline.Add(-10*time.Second))
 		supplementalDeadlineLimited = extraMeta.PartialDueToDeadline
 		if extraErr == nil && len(extraResults) > 0 {
@@ -613,15 +613,39 @@ func selectedPlatformLabel(platforms map[string]bool) string {
 	return strings.Join(labels, ", ")
 }
 
-func buildSupplementalQueries(query string, existing []string) []string {
+func buildSupplementalQueries(service *services.GeminiService, query string, existing []string, reviewed []services.AIRecommendation) []string {
+	if service != nil {
+		if generated, err := service.BuildSupplementalQueries(query, existing, reviewed); err == nil && len(generated) > 0 {
+			return mergeSupplementalQuerySets(existing, generated)
+		}
+	}
+	return buildDeterministicSupplementalQueries(query, existing, reviewed)
+}
+
+func buildDeterministicSupplementalQueries(query string, existing []string, reviewed []services.AIRecommendation) []string {
 	candidates := append([]string{}, existing...)
+	for _, item := range reviewed {
+		if item.Assessment == "positive" && item.SearchHint != "" {
+			candidates = append(candidates, item.SearchHint)
+		}
+		if (item.Assessment == "unclear" || services.IsExcludedAssessment(item.Assessment)) && item.SearchHint != "" {
+			candidates = append(candidates, query+" "+item.SearchHint)
+		}
+	}
 	candidates = append(candidates,
 		query+" cinematic stock footage",
 		query+" editorial b-roll",
 		query+" establishing shot",
 		query+" drone footage",
+		query+" authentic candid couple",
+		query+" urban park lifestyle footage",
 	)
+	return mergeSupplementalQuerySets(nil, candidates)
+}
 
+func mergeSupplementalQuerySets(base, extra []string) []string {
+	candidates := append([]string{}, base...)
+	candidates = append(candidates, extra...)
 	seen := map[string]bool{}
 	result := make([]string, 0, len(candidates))
 	for _, item := range candidates {