Fix Mentra nested Responses endpoints

crates/metacrate-grid-agent/tests/live_llm_vision.rs

@@ -50,10 +50,19 @@ async fn luna_describes_live_renderer_evidence() -> Result<(), Box<dyn Error>> {
             ContentBlock::image_url(image),
         ])
         .await?;
-    for block in response.content {
-        if let ContentBlock::Text { text } = block {
-            println!("LIVE_LLM_VISION={text}");
-        }
+    let descriptions = response
+        .content
+        .into_iter()
+        .filter_map(|block| match block {
+            ContentBlock::Text { text } if !text.trim().is_empty() => Some(text),
+            _ => None,
+        })
+        .collect::<Vec<_>>();
+    if descriptions.is_empty() {
+        return Err("Luna returned no snapshot description".into());
+    }
+    for description in descriptions {
+        println!("LIVE_LLM_VISION={description}");
     }
     Ok(())
 }