Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

templates/starter/src/pages/category/[slug].astro

@@ -0,0 +1,42 @@
+---
+import { getTerm, getEmDashCollection, decodeSlug } from "emdash";
+import { Image } from "emdash/ui";
+import Base from "../../layouts/Base.astro";
+
+const slug = decodeSlug(Astro.params.slug);
+const term = slug ? await getTerm("category", slug) : null;
+
+if (!term) {
+	return Astro.redirect("/404");
+}
+
+const { entries: posts } = await getEmDashCollection("posts", {
+	where: { category: term.slug },
+	orderBy: { published_at: "desc" },
+});
+---
+
+<Base title={`${term.label} posts`} description={`Posts in ${term.label}`}>
+	<h1>{term.label}</h1>
+	<p>{posts.length} {posts.length === 1 ? "post" : "posts"}</p>
+
+	{
+		posts.length === 0 ? (
+			<p>No posts in this category yet.</p>
+		) : (
+			<ul>
+				{posts.map((post) => (
+					<li>
+						<a href={`/posts/${post.id}`}>
+							{post.data.featured_image && (
+								<Image image={post.data.featured_image} />
+							)}
+							<h2>{post.data.title}</h2>
+						</a>
+						{post.data.excerpt && <p>{post.data.excerpt}</p>}
+					</li>
+				))}
+			</ul>
+		)
+	}
+</Base>