fix(rectification): match the delivery inside the acknowledged reply (BUG-1241)

The answered choice persists the acknowledgement, a blank line, and the
rewritten delivery. The exit fill-in required equality and wrote the
deterministic delivery again. Check containment instead, and pin it on the
real answer path. The suspected widen staleness regression did not hold;
keep a guard test.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4f2nya58RoRu4yEmJgRGE

frontend/src/lib/rectification-agentic/v9/delivery-turn-guard.ts

@@ -71,7 +71,9 @@ export function deliveryCarrierNarration(input: {
 }
 
 /**
- * True when the latest assistant text is the stored delivery sentence.
+ * True when the latest assistant text carries the stored delivery sentence.
+ * The answered choice persists 「已记录，…」 + a blank line + that sentence,
+ * so this is a containment check, not equality (BUG-1241 fix sheet).
  * Whitespace is ignored. A needle shorter than 8 characters does not match.
  */
 export function deliveryCarrierMatchesLastAssistant(input: {
@@ -91,7 +93,7 @@ export function deliveryCarrierMatchesLastAssistant(input: {
     if (turn?.role !== "assistant") continue;
     const text = typeof turn.text === "string" ? squash(turn.text) : "";
     if (!text) continue;
-    return text === needle;
+    return text.includes(needle);
   }
   return false;
 }