feat(post): enhance post handling with channel integration

- Updated PostHandler to include channel information in post responses.
- Introduced PostChannelBrief DTO to represent channel details associated with posts.
- Modified post conversion functions to support channel data, ensuring proper mapping of channel IDs to channel names.
- Enhanced ChannelRepository and ChannelService to facilitate batch retrieval of channels by IDs.
- Updated wire generation to inject channel service into post handler for improved functionality.

internal/service/channel_service.go

@@ -8,6 +8,7 @@ import (
 type ChannelService interface {
 	ListActive() ([]*model.Channel, error)
 	ListAll() ([]*model.Channel, error)
+	MapByIDs(ids []string) (map[string]*model.Channel, error)
 	Create(name, slug, description string, sortOrder int, isActive bool) (*model.Channel, error)
 	Update(id, name, slug, description string, sortOrder int, isActive bool) (*model.Channel, error)
 	Delete(id string) error
@@ -29,6 +30,20 @@ func (s *channelServiceImpl) ListAll() ([]*model.Channel, error) {
 	return s.channelRepo.ListAll()
 }
 
+func (s *channelServiceImpl) MapByIDs(ids []string) (map[string]*model.Channel, error) {
+	list, err := s.channelRepo.ListByIDs(ids)
+	if err != nil {
+		return nil, err
+	}
+	m := make(map[string]*model.Channel, len(list))
+	for _, ch := range list {
+		if ch != nil {
+			m[ch.ID] = ch
+		}
+	}
+	return m, nil
+}
+
 func (s *channelServiceImpl) Create(name, slug, description string, sortOrder int, isActive bool) (*model.Channel, error) {
 	channel := &model.Channel{
 		Name:        name,