**suggestion (performance):** Optimize data fetching in MainTopicPage

[Shloimy15e]

          **suggestion (performance):** Optimize data fetching in MainTopicPage

The current implementation fetches all videos for all subtopics at once. Consider implementing pagination or lazy loading to fetch videos only when needed, especially if there are many subtopics or videos.

  } = useInfiniteQuery(
    "videosBySubtopic",
    async ({ pageParam = 0 }) => {
      const limit = 10;
      const offset = pageParam * limit;
      return await fetchVideosBySubtopicPaginated(subtopics, offset, limit);
    },
    {
      getNextPageParam: (lastPage, pages) => pages.length,
    }
  );

Originally posted by @sourcery-ai[bot] in #35 (comment)