fix(content): update conditional checks to use mimeType for content rendering

- Replaced `type` field checks with `mimeType.startsWith("image/")` for improved accuracy in `content-card` and admin content page components.
- Adjusted `CardContent` background color for better visual consistency.

frontend/src/components/content-card.tsx

@@ -71,6 +71,7 @@ export function ContentCard({ content }: ContentCardProps) {
 		}
 	};
 
+
 	return (
 		<Card className="overflow-hidden border-none shadow-sm hover:shadow-md transition-shadow">
 			<CardHeader className="p-4 flex flex-row items-center space-y-0 gap-3">
@@ -93,9 +94,9 @@ export function ContentCard({ content }: ContentCardProps) {
 					<MoreHorizontal className="h-4 w-4" />
 				</Button>
 			</CardHeader>
-			<CardContent className="p-0 relative bg-zinc-100 dark:bg-zinc-900 aspect-square flex items-center justify-center">
+			<CardContent className="p-0 relative bg-zinc-200 dark:bg-zinc-900 aspect-square flex items-center justify-center">
 				<Link href={`/meme/${content.slug}`} className="w-full h-full relative">
-					{content.type === "meme" ? (
+					{content.mimeType.startsWith("image/") ? (
 						<Image
 							src={content.url}
 							alt={content.title}