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/wire/handler.go

@@ -64,9 +64,10 @@ func ProvideUserHandler(
 func ProvidePostHandler(
 	postService service.PostService,
 	userService service.UserService,
+	channelService service.ChannelService,
 	logService *service.LogService,
 ) *handler.PostHandler {
-	h := handler.NewPostHandler(postService, userService)
+	h := handler.NewPostHandler(postService, userService, channelService)
 	if ps, ok := postService.(interface{ SetLogService(*service.LogService) }); ok {
 		ps.SetLogService(logService)
 	}