fix(rectification): one stem on screen — a replaced focus draws nothing and the live one takes its slot (BUG-1135)

- GET attach: a live hanging focus replaces a superseded-unanswered focus
  linked to the last assistant turn instead of falling to a standalone copy.
- Client placement: a dead question on the latest message is replaceable,
  and the stem the body still ends with is stripped (stripQuestionSentences).
- Chat view: a dead question no longer turns the gap into 「没有拿到下一个问题」
  while the case has a different live question.
- Message entry: a superseded or replaced unanswered choice draws nothing
  (no stem without options); the current question keeps its stem while busy.
- Copy text skips a dead question.
- Three DOM tests reproduce 「stem, stem」 and 「dead stem + unavailable」, red then green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017eEAG8HD3mm8gsKXgk8uU8

frontend/src/components/rectification-message-entry.tsx

@@ -27,6 +27,7 @@ import {
 } from "@/lib/rectification-agentic/v9/choice-card";
 import {
   questionIsAnswered,
+  questionIsDeadUnanswered,
   type TurnQuestion,
 } from "@/lib/rectification-agentic/v9/turn-question";
 import { RECTIFICATION_STOPPED_NOTICE } from "@/lib/rectification-surface-state";
@@ -152,7 +153,16 @@ function RectificationMessageEntryView({
   const embeddedCard = question && !unansweredDeadChoice
     ? choiceCardFromQuestion(question, liveQuestion ? liveChoiceCard : null)
     : null;
-  const afterAnswer = question && displayedMessage.state === "settled"
+  // BUG-1135 (D1, supersedes BUG-917's 「stem without options」): a choice
+  // nobody can answer any more draws nothing on its message — only the live
+  // focus prints a stem, so the same stem never shows twice.
+  const replacedQuestion = Boolean(
+    question
+    && unansweredDeadChoice
+    && (questionIsDeadUnanswered(question)
+      || (currentQuestionFocusId !== null && currentQuestionFocusId !== question.focus_id)),
+  );
+  const afterAnswer = question && displayedMessage.state === "settled" && !replacedQuestion
     ? (
       <div className="rectification-message-question">
         <p className="rectification-message-question__prompt">{question.prompt}</p>

frontend/src/lib/rectification-agentic/v9/turn-question.ts

@@ -135,6 +135,16 @@ export function turnQuestionFromCurrent(
   };
 }
 
+/** A focus that was replaced before anyone answered it: nothing to show. */
+export function focusIsDeadUnanswered(focus: Pick<ConversationFocus, "status" | "answerOption">): boolean {
+  return focus.status === "superseded" && !focus.answerOption;
+}
+
+/** The same judgement on the client's question model (BUG-917 / BUG-1135). */
+export function questionIsDeadUnanswered(question: Pick<TurnQuestion, "status" | "answer_option">): boolean {
+  return question.status === "superseded" && !question.answer_option;
+}
+
 export function attachQuestionsToTurns<T extends { id: string; role: string; text: string | null }>(
   turns: readonly T[],
   focuses: readonly ConversationFocus[],
@@ -149,7 +159,11 @@ export function attachQuestionsToTurns<T extends { id: string; role: string; tex
     byTurn.set(focus.askedTurnId, focus);
   }
   const lastAssistant = [...turns].reverse().find((turn) => turn.role === "assistant");
-  if (hanging[0] && lastAssistant && !byTurn.has(lastAssistant.id)) {
+  // BUG-1135: a re-focused probe leaves its old focus linked to the turn and
+  // superseded unanswered; the live focus takes that slot instead of falling to
+  // a second, standalone copy of the same stem.
+  const linked = lastAssistant ? byTurn.get(lastAssistant.id) : undefined;
+  if (hanging[0] && lastAssistant && (!linked || focusIsDeadUnanswered(linked))) {
     byTurn.set(lastAssistant.id, hanging[0]);
   }
   return turns.map((turn) => {
@@ -325,7 +339,7 @@ export function questionIsAnswered(question: TurnQuestion): boolean {
 
 export function copyTextForMessage(body: string, question: TurnQuestion | null | undefined): string {
   const spoken = body.trim();
-  if (!question?.prompt) return spoken;
+  if (!question?.prompt || questionIsDeadUnanswered(question)) return spoken;
   const lines = [spoken, "", question.prompt];
   if (question.options?.length) {
     lines.push("");

frontend/src/lib/rectification-chat-view.ts

@@ -206,7 +206,9 @@ export function deriveRectificationChatView(input: RectificationChatViewInput) {
     && !latestSettledAssistant.question.answer_option
     && (latestSettledAssistant.question.status === "active"
       || latestSettledAssistant.question.status === "superseded")
-    && !liveQuestionOnMessages,
+    && !liveQuestionOnMessages
+    // BUG-1135: another, live question exists — it is drawn instead.
+    && !(currentQuestion && currentQuestion.focus_id !== latestSettledAssistant.question.focus_id && !deadChoice),
   );
   const questionGap = rectificationQuestionGapState({
     liveQuestionVisible: liveQuestionOnMessages,

frontend/src/lib/rectification-snapshot-messages.ts

@@ -1,6 +1,6 @@
 import { parseSegmentSummary, type SegmentSummary } from "./rectification-agentic/core/segment-summary.ts";
 import { stripQuestionSentences } from "./rectification-agentic/v9/collect-prompt.ts";
-import { parseTurnQuestion, persistedOfferFromTurn, type TurnQuestion } from "./rectification-agentic/v9/turn-question.ts";
+import { parseTurnQuestion, persistedOfferFromTurn, questionIsDeadUnanswered, type TurnQuestion } from "./rectification-agentic/v9/turn-question.ts";
 
 export type SnapshotTurnMessage = {
   role: "assistant" | "user";
@@ -111,7 +111,13 @@ export function placePersistedQuestion<T extends SnapshotTurnMessage>(
     }
   }
   const targetQuestion = target >= 0 ? current[target]!.question : undefined;
-  const hang = target >= 0 && (!targetQuestion || targetQuestion.focus_id === question.focus_id);
+  // BUG-1135: a dead (superseded, unanswered) question on the target is not a
+  // reason to draw the live one a second time in a standalone block.
+  const hang = target >= 0 && (
+    !targetQuestion
+    || targetQuestion.focus_id === question.focus_id
+    || questionIsDeadUnanswered(targetQuestion)
+  );
   let changed = false;
   const messages = current.map((message, index) => {
     if (hang && index === target) {
@@ -120,7 +126,10 @@ export function placePersistedQuestion<T extends SnapshotTurnMessage>(
       if (message.question && message.question.focus_id === question.focus_id
         && message.question.status === "active") return message;
       changed = true;
-      return { ...message, question };
+      // BUG-1135: the stem the body may still end with leaves when the card
+      // attaches — the same strip every other attach path runs.
+      const text = message.text ? stripQuestionSentences(message.text, question.prompt) : message.text;
+      return { ...message, text, question };
     }
     if (message.question?.focus_id !== question.focus_id) return message;
     changed = true;

frontend/tests/rectification-dup-question-20260926.test.tsx

@@ -566,3 +566,80 @@ test("mergeTurnQuestions drops the attached stem from the live text; appendUnsee
   );
   assert.deepEqual(inserted.map((message) => message.renderKey), ["a", "b", "live"]);
 });
+
+// 2026-10-01 (TASK-rectification-message-cleanup-20261001, BUG-1135): real
+// device 2026-09-29 showed 「stem, stem, A–D」. Two shapes can produce it.
+const SAME_STEM = "2024 年 1 月前后，你有过搬家或者长期住到外地的情况吗？";
+const RECAP = "记下了：2023 年换过工作。";
+
+test("C · a superseded focus with the same stem on the latest message: the stem shows once, the new card is tappable (BUG-1135)", async () => {
+  const turns: RawTurn[] = [
+    OPENING,
+    { id: "t1", role: "user", text: "2023 年换过工作。", status: "completed" },
+    { id: "t2", role: "assistant", text: RECAP, status: "completed" },
+  ];
+  // Same probe re-focused: the old focus was linked to t2 and superseded
+  // unanswered; the new one has no asked turn yet.
+  const old = focus(FOCUS_1, SAME_STEM, { askedTurnId: "t2", status: "superseded", resolvedAt: "2026-09-29T08:01:00.000Z" });
+  const fresh = focus(FOCUS_2, SAME_STEM);
+  const chat = await mountChat({
+    initialTurns: turns,
+    initialFocuses: [old, fresh],
+    initialCurrent: fresh,
+    route: () => json(snapshot(turns, [old, fresh], fresh)),
+  });
+  try {
+    assert.equal(chat.harness.errors.length, 0, String(chat.harness.errors[0] ?? ""));
+    assert.equal(chat.occurrences(SAME_STEM), 1, `stem must show exactly once:\n${chat.text()}`);
+    assert.equal(chat.clickableOptions().length, 4, `the live focus is tappable:\n${chat.text()}`);
+  } finally {
+    await chat.close();
+  }
+});
+
+test("C · client guard: a message still carrying a dead focus with the same stem never prints it beside the live question (BUG-1135)", async () => {
+  const turns: RawTurn[] = [
+    OPENING,
+    { id: "t1", role: "user", text: "2023 年换过工作。", status: "completed" },
+    { id: "t2", role: "assistant", text: RECAP, status: "completed" },
+  ];
+  const old = focus(FOCUS_1, SAME_STEM, { askedTurnId: "t2", status: "superseded", resolvedAt: "2026-09-29T08:01:00.000Z" });
+  const fresh = focus(FOCUS_2, SAME_STEM);
+  // A server snapshot assembled before the live focus could hang: only the
+  // dead focus is attached, the live one is the case's current question.
+  const assembled = { ...snapshot(turns, [old], fresh), turns: attachQuestionsToTurns(turns, [old]) };
+  const chat = await mountChat({
+    initialTurns: turns,
+    initialFocuses: [old],
+    initialCurrent: fresh,
+    route: () => json(assembled),
+  });
+  try {
+    assert.equal(chat.occurrences(SAME_STEM), 1, `stem must show exactly once:\n${chat.text()}`);
+    assert.equal(chat.clickableOptions().length, 4);
+  } finally {
+    await chat.close();
+  }
+});
+
+test("C · a stem left in the body of the message that receives the persisted question shows once (BUG-1135)", async () => {
+  const turns: RawTurn[] = [
+    OPENING,
+    { id: "t1", role: "user", text: "2023 年换过工作。", status: "completed" },
+    { id: "t2", role: "assistant", text: `${RECAP}${SAME_STEM}`, status: "completed" },
+  ];
+  const fresh = focus(FOCUS_2, SAME_STEM);
+  const chat = await mountChat({
+    initialTurns: turns,
+    initialFocuses: [],
+    initialCurrent: fresh,
+    route: () => json(snapshot(turns, [], fresh)),
+  });
+  try {
+    assert.ok(chat.text().includes(RECAP), "the recap stays");
+    assert.equal(chat.occurrences(SAME_STEM), 1, `stem must show exactly once:\n${chat.text()}`);
+    assert.equal(chat.clickableOptions().length, 4);
+  } finally {
+    await chat.close();
+  }
+});