兼容缺少槽位的非工具 Responses 事件

非 function_call output item 缺少 output_index 时忽略

保留 function_call 槽位缺失的 fail-closed 契约并补回归测试

server-rs/crates/platform-llm/src/lib.rs

@@ -3774,8 +3774,18 @@ fn parse_responses_output_item_event(
     let Some(item) = parsed.get("item").filter(|item| item.is_object()).cloned() else {
         return Ok(None);
     };
-    let slot = responses_output_slot(parsed)
-        .ok_or_else(|| missing_tool_slot_error("Responses", event_type, "output_index"))?;
+    let is_function_call =
+        item.get("type").and_then(serde_json::Value::as_str) == Some("function_call");
+    let Some(slot) = responses_output_slot(parsed) else {
+        if !is_function_call {
+            return Ok(None);
+        }
+        return Err(missing_tool_slot_error(
+            "Responses",
+            event_type,
+            "output_index",
+        ));
+    };
     let mut event = ParsedStreamEvent {
         output_items: vec![(slot, item.clone())],
         ..Default::default()
@@ -7432,6 +7442,29 @@ mod tests {
         .await;
     }
 
+    #[tokio::test]
+    async fn stream_run_ignores_non_tool_output_item_without_output_index() {
+        let server_url = spawn_mock_server(vec![MockResponse {
+            status_line: "200 OK",
+            content_type: "text/event-stream; charset=utf-8",
+            body: concat!(
+                r#"data: {"type":"response.output_item.added","item":{"type":"reasoning","id":"rs_1"}}"#, "\n\n",
+                r#"data: {"type":"response.output_text.delta","delta":"杭州今天多云。"}"#, "\n\n",
+                r#"data: {"type":"response.completed"}"#, "\n\n"
+            )
+            .to_string(),
+            extra_headers: Vec::new(),
+        }]);
+
+        let response = build_test_client(server_url, 0)
+            .stream_run(weather_tool_request(LlmApiKind::OpenAiResponses), |_| {})
+            .await
+            .expect("非工具 output item 缺少 output_index 不应中断流");
+
+        assert_eq!(response.text, "杭州今天多云。");
+        assert!(response.tool_calls.is_empty());
+    }
+
     #[tokio::test]
     async fn stream_run_rejects_anthropic_tool_use_without_block_index() {
         expect_stream_missing_slot_error(