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

packages/contentful-to-portable-text/src/blocks/code-block.ts

@@ -0,0 +1,12 @@
+import type { ArbitraryTypedObject } from "@portabletext/types";
+
+import type { ContentfulEntry } from "../types.js";
+
+export function transformCodeBlock(entry: ContentfulEntry, key: string): ArbitraryTypedObject {
+	return {
+		_type: "code",
+		_key: key,
+		code: (entry.fields.code as string) ?? "",
+		language: (entry.fields.language as string) ?? "",
+	};
+}