fix(project page): no skeleton bg if bg is set

Author: aster-void

src/pages/projects/[...id].astro

@@ -45,7 +45,10 @@ if (project.data.status !== "dead") {
       <Picture
         loading="eager"
         formats={["avif", "webp"]}
-        class="skeleton aspect-5/3 w-full object-cover lg:w-150 lg:rounded-2xl"
+        class:list={[
+          "aspect-5/3 w-full object-cover lg:w-150 lg:rounded-2xl",
+          !project.data.thumbnail.bg && "skeleton",
+        ]}
         alt="プロジェクト画像"
         src={project.data.thumbnail.src}
         position={project.data.thumbnail.position}
@@ -54,6 +57,7 @@ if (project.data.status !== "dead") {
         style={{
           "object-position": project.data.thumbnail.position,
           "object-fit": project.data.thumbnail.fit,
+          "background-color": project.data.thumbnail.bg || undefined,
         }}
       />
       <div class="container mx-auto mt-8 px-4 lg:mx-0 lg:flex-1">