fix(confidence-engine): extract raw openai response text

lib/llm/provider.js

@@ -69,6 +69,32 @@ function recoverJson(raw) {
   throw new SyntaxError("Model output could not be parsed as JSON: " + result.slice(0, 300) + "...");
 }
 
+function extractOpenAIResponseText(data) {
+  if (typeof data.output_text === "string" && data.output_text.length > 0) {
+    return data.output_text;
+  }
+
+  const outputText = (data.output ?? []).flatMap((item) =>
+    item?.type === "message"
+      ? (item.content ?? []).flatMap((part) =>
+          part?.type === "output_text" && typeof part.text === "string"
+            ? [part.text]
+            : [],
+        )
+      : [],
+  );
+  if (outputText.length > 0) return outputText.join("");
+
+  const outputTypes = (data.output ?? []).map((item) => item?.type ?? "unknown");
+  const contentTypes = (data.output ?? []).flatMap((item) =>
+    (item?.content ?? []).map((part) => part?.type ?? "unknown"),
+  );
+  const refusal = contentTypes.includes("refusal");
+  throw new Error(
+    `OpenAI Responses API returned no output_text (output types: ${outputTypes.join(",") || "none"}; content types: ${contentTypes.join(",") || "none"}; refusal: ${refusal})`,
+  );
+}
+
 let _chatSupported = null;
 const reconstructionJsonSchema = z.toJSONSchema(reconstructionV2Schema);
 const openAIReconstructionJsonSchema = createOpenAIStrictSchema(
@@ -458,9 +484,11 @@ class OpenAIReconstructionProvider {
     }
 
     const data = await response.json();
-    const outputText = data.output_text;
-    if (typeof outputText !== "string") {
-      const error = new Error("OpenAI Responses API returned no output_text");
+    let outputText;
+    try {
+      outputText = extractOpenAIResponseText(data);
+    } catch (cause) {
+      const error = new Error(cause.message);
       error.providerApiPath = "/v1/responses";
       throw error;
     }