fix(rectification): server-append spoken collect stems after free-text turns

Choice path already wrote spokenFollowupForUser into the body; free-text
dropped that stem and only filled empty answers, so a new collect_spoken
focus stayed invisible after “记下了”.

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

frontend/src/app/api/rectification/agent/route.ts

@@ -14,7 +14,7 @@ import {
   applyRectificationChoice,
   applyCollectFocusDenial,
   persistNextInterviewIfIdle,
-  persistEmptyCollectSpokenAssistant,
+  persistCollectSpokenAssistantIfNew,
 } from "@/lib/rectification-agentic/v9/answer-choice";
 import { mapRectificationRpcError } from "@/lib/rectification-agentic/v9/case-service";
 import { CHOICE_ACTION, STOP_ACTION } from "@/lib/rectification-agentic/v9/choice-action";
@@ -668,32 +668,35 @@ export async function POST(request: Request) {
           send({ type: "error", message: "生时校正暂时不可用，请稍后重试。" });
         } else {
           if (action === "message") {
+            let idleHostNarration: string | null = null;
             try {
-              await persistNextInterviewIfIdle({
+              const idle = await persistNextInterviewIfIdle({
                 accounting: accounting as never,
                 userId,
                 caseId,
               });
+              idleHostNarration = idle.hostNarration;
             } catch (error) {
               console.warn(
                 `[rectification-v9] persist next interview after turn failed case=${caseId} reason=${error instanceof Error ? error.name : "Unknown"}`,
               );
             }
-            if (!result.answerText.trim()) {
-              try {
-                const fallback = await persistEmptyCollectSpokenAssistant({
-                  accounting: accounting as never,
-                  userId,
-                  caseId,
-                  requestId: crypto.randomUUID(),
-                  answerText: result.answerText,
-                });
-                if (fallback) send({ type: "answer.delta", text: fallback });
-              } catch (error) {
-                console.warn(
-                  `[rectification-v9] empty collect spoken fallback failed case=${caseId} reason=${error instanceof Error ? error.name : "Unknown"}`,
-                );
-              }
+            try {
+              const fallback = await persistCollectSpokenAssistantIfNew({
+                accounting: accounting as never,
+                userId,
+                caseId,
+                requestId: crypto.randomUUID(),
+                answerText: result.answerText,
+                previousFocusId: result.previousFocusId,
+                alreadyEmitted: result.collectSpokenEmitted,
+                hostNarration: idleHostNarration,
+              });
+              if (fallback) send({ type: "answer.delta", text: fallback });
+            } catch (error) {
+              console.warn(
+                `[rectification-v9] collect spoken visibility fallback failed case=${caseId} reason=${error instanceof Error ? error.name : "Unknown"}`,
+              );
             }
           }
           send({ type: "done", emitted: true });