fix(rectification): narrate exhausted-probe adopt instead of keep-collecting

When leftover probes cannot split adjacent minutes, skip frameless follow-ups and let a no-tool agent explain the stop. Distinguish-card "no" no longer closes a whole evidence domain.

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

frontend/src/lib/rectification-agentic/user-copy.ts

@@ -74,6 +74,8 @@ export type RangeNarrationInput = {
   openingRange?: readonly [string, string] | null;
   variant?: RangeNarrationVariant;
   stopReason?: string | null;
+  /** Extra stop sentence after BUG-503 prefixes; used when the probe pool is exhausted. */
+  stopExplain?: string | null;
 };
 
 function clockMinutes(value: string): number | null {
@@ -137,6 +139,8 @@ export function nonConvergingRangeNarration(
     ? progressClause(input.openingRange, rangeText, range)
     : null;
   const reason = variant === "delivery" ? stopReasonPrefix(input.stopReason) : null;
+  const explain = variant === "delivery" ? (input.stopExplain?.trim() || null) : null;
+  const prefix = [reason, explain].filter(Boolean).join("");
 
   if (variant === "intermediate") {
     if (rangeText && representative) {
@@ -155,19 +159,19 @@ export function nonConvergingRangeNarration(
     const head = progress ?? `更站得住的范围是 ${rangeText}，代表分钟 ${representative}`;
     const representativeClause = progress ? `。代表分钟是 ${representative}。` : `。`;
     const body = `${head}${representativeClause}${boundaryCopy}`;
-    return reason ? `${reason}${body}` : body;
+    return prefix ? `${prefix}${body}` : body;
   }
   if (rangeText) {
     const head = progress ?? `更站得住的范围是 ${rangeText}`;
     const body = `${head}。${boundaryCopy}`;
-    return reason ? `${reason}${body}` : body;
+    return prefix ? `${prefix}${body}` : body;
   }
   if (representative) {
     const body = `当前代表分钟 ${representative}。${boundaryCopy}`;
-    return reason ? `${reason}${body}` : body;
+    return prefix ? `${prefix}${body}` : body;
   }
   const body = `当前几个候选还分不开。${boundaryCopy}`;
-  return reason ? `${reason}${body}` : body;
+  return prefix ? `${prefix}${body}` : body;
 }
 
 export function deliveryAdoptNarration(input: RangeNarrationInput): string {