feat: enhance components with new features and optimizations

- Added support for conditional rendering of the NekoFollower component in AppShell based on ENABLE_NEKO_FOLLOWER.
- Introduced MarkdownImage component in BlogDetailContent for handling images in markdown, supporting both local and external assets.
- Improved BlogToc component to use IntersectionObserver for better performance in tracking active headings.
- Refactored ContentContent to utilize YoutubeLiteEmbed for embedding YouTube videos, simplifying the video rendering logic.
- Created a new YoutubeLiteEmbed component for lazy loading YouTube videos with thumbnail previews.
- Updated site-settings to include ENABLE_NEKO_FOLLOWER constant for feature toggling.
- Enhanced next.config.ts with image optimization settings for better performance.
- Refactored snippets-content to improve code readability and structure.
- Cleaned up home-hero and home-videos-section components for better layout and performance.

components/app-shell.tsx

@@ -6,7 +6,7 @@ import { usePathname } from "next/navigation";
 import { AnnouncementBar } from "poyraz-ui/organisms";
 import { SiteNavbar } from "@/components/site-navbar";
 import { NekoFollower } from "@/components/neko-follower";
-import { ANNOUNCEMENT_ITEMS } from "@/data/site-settings";
+import { ANNOUNCEMENT_ITEMS, ENABLE_NEKO_FOLLOWER } from "@/data/site-settings";
 
 type AppShellProps = {
   children: React.ReactNode;
@@ -15,7 +15,8 @@ type AppShellProps = {
 export function AppShell({ children }: AppShellProps) {
   const pathname = usePathname();
   const announcement = ANNOUNCEMENT_ITEMS[0];
-  const isStandaloneLinksPage = pathname === "/links" || pathname.startsWith("/links/");
+  const isStandaloneLinksPage =
+    pathname === "/links" || pathname.startsWith("/links/");
 
   if (isStandaloneLinksPage) {
     return children;
@@ -23,7 +24,7 @@ export function AppShell({ children }: AppShellProps) {
 
   return (
     <>
-      <NekoFollower />
+      {ENABLE_NEKO_FOLLOWER ? <NekoFollower /> : null}
       <div className="mx-auto flex w-full max-w-4xl flex-col px-4 py-4 sm:px-6">
         <SiteNavbar />
         {announcement ? (