fix(consult): BUG-950~953 Pass 4 按句放行，无分钟按句丢弃

正文不再整段 hold：闭合句立刻过 Pass 4，无 reject 即发（950）。
无出生分钟改为按句丢弃，全丢才用兜底句（951）；该模式日期记 observe（952）。
校正流 token 级 thinking 死链按 P2 删除，测试翻转成否定合同（953）。

frontend/tests/rectification-v9-stream.test.ts

@@ -5,8 +5,6 @@ import test from "node:test";
 import {
   mapStreamChunkToActivity,
   mapStreamChunkToPhase,
-  mapStreamChunkToThinking,
-  toPublicThinkingDelta,
   safePublicEvent,
   streamToolNames,
 } from "../src/lib/rectification-agentic/v9/stream-mapping.ts";
@@ -173,20 +171,12 @@ test("reasoning, raw payloads, provider metadata and step internals never map to
 });
 
 test("Chinese thinking stays internal and is never a public stream event", () => {
-  assert.deepEqual(
-    mapStreamChunkToThinking(chunk("reasoning-delta", { text: "先核对升学年份。" }) as never),
-    { type: "thinking.delta", text: "先核对升学年份。" },
-  );
-  assert.equal(
-    mapStreamChunkToThinking(chunk("reasoning-delta", {
-      text: "The proposedKind value was rejected",
-    }) as never),
-    null,
-  );
-  assert.equal(
-    toPublicThinkingDelta("The proposedKind value was rejected because education is invalid"),
-    null,
-  );
+  // 原值：mapStreamChunkToThinking / toPublicThinkingDelta 把中文 reasoning 收成内部 thinking.delta
+  // 新值：源码不得存在这两个函数；reasoning-delta 不映射成对外事件；thinking.delta 仍被安全层丢掉
+  // 原因：BUG-953，死链按 P2 删除，翻转成否定合同
+  const mapping = readFileSync(new URL("../src/lib/rectification-agentic/v9/stream-mapping.ts", import.meta.url), "utf8");
+  assert.doesNotMatch(mapping, /function mapStreamChunkToThinking|function toPublicThinkingDelta|InternalThinkingDeltaEvent/);
+  assert.equal(mapStreamChunkToPhase(chunk("reasoning-delta", { text: "先核对升学年份。" }) as never), null);
   assert.equal(safePublicEvent({ type: "thinking.delta", text: "先核对升学年份。" }), null);
   assert.equal(safePublicEvent({
     type: "thinking.delta",