fix: address code review findings

internal/routing/search_cache.go

@@ -2,6 +2,7 @@ package routing
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 
 	"trip-planner/internal/cache"
@@ -74,19 +75,23 @@ func (s *SearchCacheService) performYandexSearch(ctx context.Context, from, to,
 
 // parseItineraryFromBytes parses an itinerary from byte data.
 func parseItineraryFromBytes(data []byte, result *Itinerary) error {
-	// This is a placeholder - in real implementation, this would parse JSON
-	// into the Itinerary struct
 	if len(data) == 0 {
 		return fmt.Errorf("empty data")
 	}
+	if err := json.Unmarshal(data, result); err != nil {
+		return fmt.Errorf("failed to parse itinerary from bytes: %w", err)
+	}
 	return nil
 }
 
 // convertResponseToBytes converts Yandex API response to bytes for caching.
 func convertResponseToBytes(resp *yandex.Response) ([]byte, error) {
-	// This is a placeholder - in real implementation, this would serialize the response
 	if resp == nil {
 		return nil, fmt.Errorf("nil response")
 	}
-	return []byte(`{"search":{"from":"%s","to":"%s"},"segments":[]}`), nil
+	data, err := json.Marshal(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal response: %w", err)
+	}
+	return data, nil
 }