fix(web): restore rectification discriminator cards and stop-offer path

Coverage-complete ties never persisted A/B/C/D because contrast probes were stamped with an answered education quality probe, remaining minutes were asked as window D10 signs, and 「没有了」 missed the stop pattern.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/tests/rectification-inference-machine.test.ts

@@ -322,6 +322,15 @@ test("holdout events stay out of training and a winner must stay stable for two
     [{ id: "job", domain: "career", year: 2019, precision: "year" }],
   );
   assert.equal(matching[0]?.classified_from, "evidence");
+  const quality = {
+    ...probe({ id: "p-quality", domain: "education", year: 2016, gain: 0, yesSupports: ["05:00"], yesConflicts: ["05:10"] }),
+    source: "known_event_quality",
+  };
+  const skippedQuality = answersFromEvidence(
+    [quality],
+    [{ id: "enroll", domain: "education", year: 2016, precision: "year" }],
+  );
+  assert.equal(skippedQuality.length, 0);
 });
 
 test("C without new evidence updates the posterior immediately and D only marks the split asked", () => {
@@ -385,6 +394,50 @@ test("C without new evidence updates the posterior immediately and D only marks
   })], unsure.state.answered_probes)?.id, "p-other");
 });
 
+test("A/B/C/D on a remaining-minute contrast probe moves the posterior", () => {
+  const contrast: ConflictProbe = {
+    id: "contrast:varga.d24.05:00/05:06|05:07",
+    semantic_key: "varga.d24.05:00/05:06|05:07",
+    candidate_split_hash: "varga.d24.05:00/05:06|05:07",
+    domain: "education",
+    year: 0,
+    question: "学业盘还分得开",
+    candidate_ids: ["05:00", "05:06", "05:07"],
+    expected_outcomes: [
+      { answer_class: "yes", supports: ["05:00"], conflicts: ["05:06", "05:07"] },
+      { answer_class: "no", supports: ["05:06", "05:07"], conflicts: ["05:00"] },
+      { answer_class: "unsure", supports: [], conflicts: [] },
+    ],
+    information_gain: 0.16,
+    source: "varga_contrast",
+  };
+  const state = buildInferenceState({
+    range_start: "04:45",
+    range_end: "05:15",
+    candidates: [
+      { id: "05:00", time: "05:00", relative_support: 34 },
+      { id: "05:06", time: "05:06", relative_support: 33 },
+      { id: "05:07", time: "05:07", relative_support: 33 },
+    ],
+    events: [{ id: "e1", domain: "education", year: 2016, precision: "year" }],
+    probes: [contrast],
+  });
+  const before = posteriorMap(state.candidates);
+  const applied = applyChoiceWithoutEvidence(state, {
+    choiceKey: "C",
+    schema: {
+      choice: { prompt: "那次考试有没有发挥失常？" },
+      probe_id: contrast.id,
+      semantic_key: contrast.semantic_key,
+    },
+  });
+  assert.equal(applied.applied, true);
+  assert.equal(applied.answerClass, "no");
+  assert.notDeepEqual(posteriorMap(applied.state.candidates), before);
+  assert.ok((applied.state.candidates.find((item) => item.time === "05:06")?.posterior_score ?? 0)
+    > (applied.state.candidates.find((item) => item.time === "05:00")?.posterior_score ?? 0));
+});
+
 test("holdout and collection declines do not write a probe answer", () => {
   const conflict = probe({
     id: "p-holdout",