fix(rectification): dedupe post-adopt verify and skip this probe only

Adopted reverse-verify repeated already-asked collect stems, treated 「这题跳过」 as stopping the case, and promised holdout/OOS checks that never ran. Collect spoken stems no longer prefix a year.

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

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

@@ -77,6 +77,7 @@ test("the question gap is a live row with retries, then a reload; it never tells
   assert.match(chat, /const questionGap = rectificationQuestionGapState\(\{/);
   assert.match(chat, /questionGap === "preparing" && \(/);
   assert.match(chat, /questionGap === "unavailable" && \(/);
+  assert.match(chat, /questionGap === "verified_idle" && \(/);
   assert.match(chat, /RECTIFICATION_QUESTION_UNAVAILABLE_COPY/);
   assert.match(chat, /RECTIFICATION_QUESTION_RELOAD_LABEL/);
   assert.match(chat, /useVisibilityAwarePoll\(\{\s*enabled: questionGap === "preparing",\s*intervalMs: RECTIFICATION_QUESTION_RETRY_INTERVAL_MS,/);