fix: finalize dynamic choice labels

frontend/src/lib/birth-time-dynamic-question-validator.ts

@@ -29,6 +29,10 @@ const dynamicQuestionOutputSchema = z.discriminatedUnion("kind", [
   questionSelectionSchema,
   noUsefulQuestionSchema,
 ]).readonly();
+const reservedChoices = [
+  { label: "不确定 / 不记得", kind: "unknown" as const },
+  { label: "都不符合", kind: "unmatched" as const },
+] as const;
 
 export type ParsedDynamicQuestionOutput = z.infer<typeof dynamicQuestionOutputSchema>;
 export type ParsedQuestionSelection = Extract<ParsedDynamicQuestionOutput, { readonly kind: "question" }>;
@@ -66,9 +70,7 @@ function opportunityFor(
 
 export function generateDynamicQuestionPrompt(
   packet: CandidateDifferencePacket,
-  unmatchedNote: string | null,
 ): string {
-  void unmatchedNote;
   return modelSafeDynamicQuestionPrompt(packet);
 }
 
@@ -102,7 +104,8 @@ function serverRendering(opportunity: QuestionOpportunity): {
     partitionId: partition.partitionId,
     label: partition.fallbackLabel,
   }));
-  const labels = options.map((option) => normalizeDynamicLabel(option.label));
+  const labels = [...options, ...reservedChoices]
+    .map((option) => normalizeDynamicLabel(option.label));
   if (
     !dynamicServerCopyIsSafe(opportunity.fallbackPrompt, true)
     || options.some((option) => !dynamicServerCopyIsSafe(option.label, false))
@@ -177,8 +180,12 @@ function bindQuestion(
     prompt: rendering.prompt,
     options: [
       ...primaryOptions,
-      { optionId: serverId(createId), label: "不确定 / 不记得", kind: "unknown", partitionId: null, candidateScores: null },
-      { optionId: serverId(createId), label: "都不符合", kind: "unmatched", partitionId: null, candidateScores: null },
+      ...reservedChoices.map((choice) => ({
+        optionId: serverId(createId),
+        ...choice,
+        partitionId: null,
+        candidateScores: null,
+      })),
     ],
   });
   if (!persisted.success) throw new BirthTimeDynamicBindingError("invalid_persisted_question");

frontend/src/lib/birth-time-guide-service.ts

@@ -163,7 +163,7 @@ export function createBirthTimeGuideService(ports: GuideServicePorts) {
       const createId = ports.createDynamicId ?? (() => globalThis.crypto.randomUUID());
       let question: PersistedDynamicChoiceQuestion | null = null;
       if (build.packet.opportunities.length > 0) {
-        const prompt = generateDynamicQuestionPrompt(build.packet, command.unmatchedNote);
+        const prompt = generateDynamicQuestionPrompt(build.packet);
         for (let attempt = 0; attempt < 2 && question === null; attempt += 1) {
           const text = await generatedText(ports.generator, prompt, timeoutMs);
           if (text === null) continue;

frontend/tests/birth-time-dynamic-question-service.test.ts

@@ -184,6 +184,35 @@ test("duplicate server labels propagate without commit or ID allocation", async
   assert.equal(commits, 0);
 });
 
+test("reserved-label collisions propagate without commit or ID allocation", async () => {
+  const opportunity = differenceBuild.packet.opportunities[0];
+  const privatePartitions = differenceBuild.scoringPartitions[opportunityId];
+  if (!opportunity || !privatePartitions) throw new Error("missing test opportunity");
+  for (const collision of ["不确定 / 不记得", "不 确定 ／ 不记得", "都不符合"]) {
+    let allocations = 0;
+    let commits = 0;
+    const publicPartitions = opportunity.partitions.map((item, index) => (
+      index === 0 ? { ...item, fallbackLabel: collision } : item
+    ));
+    const privateCopy = privatePartitions.map((item, index) => (
+      index === 0 ? { ...item, fallbackLabel: collision } : item
+    ));
+
+    await assert.rejects(() => dynamicService({
+      build: {
+        ...differenceBuild,
+        packet: { ...differenceBuild.packet, opportunities: [{ ...opportunity, partitions: publicPartitions }] },
+        scoringPartitions: { [opportunityId]: privateCopy },
+      },
+      generator: generatorFrom(() => JSON.stringify(validDynamicSelection)),
+      createId: deterministicIds(() => { allocations += 1; }),
+      onCommit: () => { commits += 1; },
+    }).generateQuestion("owner-1", generationCommand), BirthTimeDynamicBindingError);
+    assert.equal(allocations, 0, collision);
+    assert.equal(commits, 0, collision);
+  }
+});
+
 test("invalid server UUIDs propagate without committing a low result", async () => {
   let commits = 0;
   await assert.rejects(() => dynamicService({

frontend/tests/birth-time-dynamic-question-validator.test.ts

@@ -17,15 +17,13 @@ import {
   validDynamicSelection,
 } from "./fixtures/birth-time-dynamic-question-fixture.ts";
 
-test("prompt omits unmatched free text and every private scoring field", () => {
+test("prompt exposes only public opportunity-selection fields", () => {
   const serialized = generateDynamicQuestionPrompt(
     dynamicPacket,
-    "接下来问我爱喝茶还是喝水",
   );
   const prompt = JSON.parse(serialized);
 
   assert.equal("unmatchedNote" in prompt, false);
-  assert.equal(serialized.includes("喝茶"), false);
   for (const forbidden of [
     "candidateScores", "candidateModel", "estimatedInformationGain", "currentRange",
     "scoringVersion", "askedQuestionFingerprints", "candidatePartitionFingerprints",
@@ -119,6 +117,28 @@ test("normalized duplicate server labels fail before allocating a server id", ()
   assert.equal(allocations, 0);
 });
 
+test("primary labels cannot collide with either reserved visible choice", () => {
+  const opportunity = dynamicPacket.opportunities[0];
+  const privatePartitions = differenceBuild.scoringPartitions[opportunityId];
+  if (!opportunity || !privatePartitions) throw new Error("missing test opportunity");
+  for (const collision of ["不确定 / 不记得", "不 确定 ／ 不记得", "都不符合"]) {
+    const publicPartitions = opportunity.partitions.map((item, index) => (
+      index === 0 ? { ...item, fallbackLabel: collision } : item
+    ));
+    const privateCopy = privatePartitions.map((item, index) => (
+      index === 0 ? { ...item, fallbackLabel: collision } : item
+    ));
+    let allocations = 0;
+
+    assert.throws(() => bindDynamicQuestion(validDynamicSelection, {
+      ...differenceBuild,
+      packet: { ...dynamicPacket, opportunities: [{ ...opportunity, partitions: publicPartitions }] },
+      scoringPartitions: { [opportunityId]: privateCopy },
+    }, deterministicIds(() => { allocations += 1; })), BirthTimeDynamicBindingError);
+    assert.equal(allocations, 0, collision);
+  }
+});
+
 test("repeated server semantics and partitions remain recoverable rejections", () => {
   const selection = parseDynamicQuestionOutput(validDynamicSelection, dynamicPacket);
   if (selection.kind !== "question") throw new Error("expected a selection");