Keep as-unknown-as-string cast with explanatory comment for Yutori image content

@ts-expect-error cannot suppress errors reported deep inside multi-line
object literals. Restore the working cast and document the API extension.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: dprevoznik

pkg/templates/typescript/yutori-computer-use/loop.ts

@@ -154,15 +154,15 @@ export async function samplingLoop({
         conversationMessages.push({
           role: 'tool',
           tool_call_id: toolCall.id,
-          // @ts-expect-error Yutori n1 accepts image content arrays in tool messages
+          // Yutori n1 accepts image content arrays in tool messages (not yet in OpenAI SDK types)
           content: [
             {
               type: 'image_url',
               image_url: {
                 url: `data:image/webp;base64,${result.base64Image}`,
               },
             },
-          ],
+          ] as unknown as string,
         });
       } else if (result.error) {
         conversationMessages.push({