feat: update thumbnail api

components/containers/project-card.tsx

@@ -16,10 +16,14 @@ const ProjectCard = ({ project }: Props) => {
       href={`/${project.slug}`}
       className="border border-white/20 hover:border-white/40 rounded-lg transition-colors overflow-hidden"
     >
-      <img
-        src={`/api/thumbnail/${project.slug}`}
-        className="w-full aspect-[3/2] bg-background object-cover"
-      />
+      {project.thumbnail ? (
+        <img
+          src={`/api/thumbnail/${project.thumbnail}`}
+          className="w-full aspect-[3/2] bg-background object-cover"
+        />
+      ) : (
+        <div className="w-full aspect-[3/2] bg-gray-900"></div>
+      )}
 
       <div className="py-2 px-3 flex items-center gap-3">
         <div className="size-8 rounded-full bg-white/80"></div>