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

docs/current-handoff.md

@@ -151,6 +151,11 @@
 - An experiment-only reconstruction-only seam now returns after initial reconstruction and graph construction, before `determineGraphBackedQuestion`. Normal production/default `startCase()` behavior remains unchanged; explicit OpenAI helper selection guarantees one selected reconstruction provider call and zero downstream question-generation calls.
 - Zero live calls occurred while implementing and verifying this seam. Next boundary: exactly one live Terra reconstruction with no retry.
 
+## OpenAI Responses text extraction
+
+- The first reconstruction-only Terra request reached inference successfully, but native-fetch parsing relied on SDK-only `output_text` and could not extract the raw response. The provider now reads documented `output[].content[].output_text` parts in response order while retaining the convenience-property path.
+- No tool-call assumption was introduced; canonical schema, prompt, transport compatibility, and reasoning remain unchanged. Zero live calls occurred during this correction; next boundary is exactly one live Terra reconstruction with no retry and no Ollama call.
+
 ## Current product architecture
 
 Three distinct routes, not a single page:

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;
+    let outputText;
-    if (typeof outputText !== "string") {
+    try {
-      const error = new Error("OpenAI Responses API returned no output_text");
+      outputText = extractOpenAIResponseText(data);
+    } catch (cause) {
+      const error = new Error(cause.message);
       error.providerApiPath = "/v1/responses";
       throw error;
     }

tests/llm/provider.test.js

@@ -239,6 +239,65 @@ describe("OpenAI reconstruction provider experiment seam", () => {
     });
   });
 
+  it("extracts ordered output_text parts from raw Responses output", async () => {
+    const provider = createOpenAIReconstructionProvider({
+      apiKey: "test-key",
+      fetchImpl: vi.fn().mockResolvedValue({
+        ok: true,
+        json: async () => ({
+          output: [
+            { type: "reasoning", content: [] },
+            {
+              type: "message",
+              role: "assistant",
+              content: [
+                { type: "output_text", text: '{"reconstruction":' },
+                { type: "output_text", text: '"result"}' },
+              ],
+            },
+          ],
+        }),
+      }),
+    });
+
+    await expect(provider.generateReconstruction("prompt")).resolves.toEqual({
+      response: { reconstruction: "result" },
+      providerApiPath: "/v1/responses",
+    });
+  });
+
+  it("preserves output_text convenience responses", async () => {
+    const provider = createOpenAIReconstructionProvider({
+      apiKey: "test-key",
+      fetchImpl: vi.fn().mockResolvedValue({
+        ok: true,
+        json: async () => ({ output_text: '{"reconstruction":"result"}' }),
+      }),
+    });
+
+    await expect(provider.generateReconstruction("prompt")).resolves.toEqual({
+      response: { reconstruction: "result" },
+      providerApiPath: "/v1/responses",
+    });
+  });
+
+  it("fails safely when a raw Responses result has no output text", async () => {
+    const provider = createOpenAIReconstructionProvider({
+      apiKey: "test-key",
+      fetchImpl: vi.fn().mockResolvedValue({
+        ok: true,
+        json: async () => ({
+          output: [{ type: "message", content: [{ type: "refusal" }] }],
+        }),
+      }),
+    });
+
+    await expect(provider.generateReconstruction("prompt")).rejects.toMatchObject({
+      providerApiPath: "/v1/responses",
+      message: expect.stringContaining("refusal: true"),
+    });
+  });
+
   it("surfaces Responses API failures without inventing reconstruction content", async () => {
     const provider = createOpenAIReconstructionProvider({
       apiKey: "test-key",