fix(rectification): ask reverse-inference probes at engine dasha months

Keep Vimshottari/Narayana start dates instead of truncating to year, so
same-year month splits can appear on the choice card.

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

frontend/tests/rectification-choice-card.test.ts

@@ -128,6 +128,42 @@ test("choice frames ask one biographical event from a server probe, not competin
   assert.equal(mergeChoiceCard(frame, null), null);
 });
 
+test("choice frames keep the engine month lock instead of collapsing to a year", () => {
+  const frame = buildChoiceFrame(
+    {
+      method_id: "d10_career",
+      ask_theme: "dated_event",
+      domain: "career",
+      user_prompt_hint: "unused",
+    },
+    {
+      evidence: [{
+        status: "confirmed",
+        domain: "education",
+        datePrecision: "year",
+        occurredFrom: "2016-01-01",
+        occurredTo: null,
+      }],
+      probes: [{
+        ...MOVE_PROBE,
+        year: 2018,
+        month: 3,
+        year_label: "2018 年 3 月前后",
+        domain: "career",
+        event_family: "入职、升职或职责明显加重",
+        source: "dasha_boundary",
+        user_meaning: "时间范围锁定 2018 年 3 月前后；领域锁定 career。",
+        semantic_key: "career.2018.03.dasha_boundary",
+      }],
+    },
+  );
+  assert.ok(frame);
+  assert.equal(frame.period, "2018 年 3 月前后");
+  assert.match(frame.prompt, /2018 年 3 月前后/);
+  assert.match(frame.why, /2018 年 3 月前后/);
+  assert.doesNotMatch(frame.period, /^2018 年前后$/);
+});
+
 test("server-owned card names the event family, not a generic 有没有这件事", () => {
   const frame = buildChoiceFrame(
     {

frontend/tests/rectification-distinguish-contract.test.ts

@@ -74,6 +74,32 @@ test("receipt parser drops invalid distinguish probes and known_event_quality",
   assert.ok((parsed[0]?.information_gain ?? 0) > 0);
 });
 
+test("receipt parser keeps engine month on dasha boundary probes", () => {
+  const parsed = parseDiscriminatingEventProbes([{
+    year: 2018,
+    month: 3,
+    year_label: "2018 年 3 月前后",
+    domain: "career",
+    event_family: "职责变化",
+    source: "dasha_boundary",
+    tracks: ["vimshottari", "narayana"],
+    tracks_agree: true,
+    unique_minute_claim: false,
+    user_meaning: "时间范围锁定 2018 年 3 月前后",
+    role: "distinguish",
+    information_gain: 0.4,
+    semantic_key: "career.2018.03.dasha_boundary",
+    candidate_ids: ["05:00", "05:20"],
+    expected_outcomes: [
+      { answer_class: "yes", supports: ["05:00"], conflicts: ["05:20"] },
+      { answer_class: "no", supports: ["05:20"], conflicts: ["05:00"] },
+    ],
+  }]);
+  assert.equal(parsed[0]?.month, 3);
+  assert.equal(parsed[0]?.year_label, "2018 年 3 月前后");
+  assert.equal(parsed[0]?.source, "dasha_boundary");
+});
+
 test("randomized hidden mutated answers change posterior only when mapped", () => {
   const probe = probeFromEngine({
     year: 2018,

frontend/tests/rectification-eight-method.test.ts

@@ -358,6 +358,30 @@ test("dasha conflict probe jumps after four scoreable events leave three trainin
   }), "collect_evidence");
 });
 
+test("dasha conflict probe keeps the engine month on the choice card", () => {
+  const plan = buildMethodFollowupPlan({
+    evidence: [
+      datedEvidence("education", "2016"),
+      datedEvidence("education", "2020"),
+      datedEvidence("relationship", "2018"),
+      datedEvidence("family", "2023"),
+    ],
+    eventProbes: [{
+      ...CAREER_CONFLICT_PROBE,
+      month: 3,
+      year_label: "2018 年 3 月前后",
+      source: "dasha_boundary",
+      user_meaning: "时间范围锁定 2018 年 3 月前后；领域锁定 career。",
+      semantic_key: "career.2018.03.dasha_boundary",
+    }],
+  });
+  assert.equal(plan.next_followup?.source, "event_probe");
+  assert.equal(plan.next_followup?.choice_frame?.period, "2018 年 3 月前后");
+  assert.equal(plan.next_followup?.year_label, "2018 年 3 月前后");
+  assert.equal(plan.next_followup?.probe_month, 3);
+  assert.match(plan.next_followup?.user_prompt_hint ?? "", /2018 年 3 月前后/);
+});
+
 test("three scoreable events in one domain still rotate methods instead of reverse-inferring", () => {
   const plan = buildMethodFollowupPlan({
     evidence: [