Tolerate Gemini image expansion drift

backend/services/gemini.go

@@ -147,6 +147,11 @@ func (g *GeminiService) ExpandImageQueries(query string) ([]string, error) {
 	}
 	jsonText, err := extractJSONObject(rawText)
 	if err != nil {
+		if looseQueries := parseLooseImageExpansionLines(rawText); len(looseQueries) == 5 {
+			g.setCachedExpansion(cacheKey, looseQueries, 15*time.Minute)
+			g.debug("gemini:image_expand_success", map[string]any{"query": trimmed, "queries": looseQueries, "mode": "loose_text"})
+			return looseQueries, nil
+		}
 		g.debug("gemini:image_expand_parse_error", map[string]any{"query": trimmed, "error": err.Error()})
 		g.setCachedExpansion(cacheKey, fallback, 15*time.Minute)
 		return fallback, err
@@ -801,6 +806,34 @@ func truncateForError(text string, limit int) string {
 	return trimmed[:limit] + "..."
 }
 
+func parseLooseImageExpansionLines(text string) []string {
+	candidates := make([]string, 0, 8)
+	for _, line := range strings.Split(text, "\n") {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "" {
+			continue
+		}
+		trimmed = strings.TrimPrefix(trimmed, "- ")
+		trimmed = strings.TrimPrefix(trimmed, "* ")
+		trimmed = strings.TrimPrefix(trimmed, "1. ")
+		trimmed = strings.TrimPrefix(trimmed, "2. ")
+		trimmed = strings.TrimPrefix(trimmed, "3. ")
+		trimmed = strings.TrimPrefix(trimmed, "4. ")
+		trimmed = strings.TrimPrefix(trimmed, "5. ")
+		trimmed = strings.TrimSpace(strings.Trim(trimmed, "\"'`"))
+		lower := strings.ToLower(trimmed)
+		if strings.HasPrefix(lower, "here is") || strings.HasPrefix(lower, "json") || strings.HasPrefix(lower, "output") {
+			continue
+		}
+		candidates = append(candidates, trimmed)
+	}
+	queries := normalizeImageExpansionQueries(candidates)
+	if len(queries) < 5 {
+		return nil
+	}
+	return queries[:5]
+}
+
 func normalizeKoreanReason(reason string) string {
 	trimmed := strings.TrimSpace(reason)
 	if trimmed == "" {

backend/services/gemini_test.go

@@ -145,6 +145,26 @@ func TestExpandImageQueriesFallsBackWhenGeminiFails(t *testing.T) {
 	}
 }
 
+func TestExpandImageQueriesAcceptsLoosePlainTextList(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"candidates":[{"content":{"parts":[{"text":"Here is the JSON requested\n1. cute cat\n2. cute cat gif\n3. cat reaction gif\n4. cat meme gif\n5. animated cat sticker"}]}}]}`))
+	}))
+	defer server.Close()
+
+	service := NewGeminiService("dummy-key", "gemini-2.5-flash")
+	service.Client = &http.Client{Timeout: 2 * time.Second}
+	service.GenerateEndpoint = server.URL
+
+	queries, err := service.ExpandImageQueries("고양이")
+	if err != nil {
+		t.Fatalf("expected loose plain-text list to be accepted, got %v", err)
+	}
+	if len(queries) != 5 || queries[0] != "cute cat" || queries[4] != "animated cat sticker" {
+		t.Fatalf("unexpected loose parsed queries: %#v", queries)
+	}
+}
+
 func TestSelectUnevaluatedCandidatesSkipsReviewedLinks(t *testing.T) {
 	ranked := []SearchResult{
 		{Link: "https://a.example"},

backend/services/giphy.go

@@ -168,7 +168,6 @@ func (s *GiphyService) SearchImages(query string, requestedMax int) (GiphySearch
 	expandedQueries, expansionErr := s.expandQueries(response.OriginalQuery)
 	response.ExpandedQueries = expandedQueries
 	if expansionErr != nil {
-		response.Warning = "Query expansion failed, using fallback search terms."
 		s.debug("giphy:query_expansion_fallback", map[string]any{
 			"query":   response.OriginalQuery,
 			"queries": expandedQueries,