fix(rectification): keep opening greeting across set-focus

set-focus only attaches the question stem. Retracting live Chinese before
it wiped the opening hello with an empty replace. Other public tools still
retract planning prose.

BUG-533.

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

CHANGELOG.md

@@ -1,5 +1,9 @@
 # 印度占星 Skill 更新日志
 
+## 2026-09-04 — 开场打招呼不再被 set-focus 清掉
+
+生时校正开场先播出的打招呼会留在同一条消息里。`rectification-set-focus` 只负责题干，不再发空的 `replace` 把正文抹掉。Skill 版本未变。
+
 ## 2026-09-04 — 未确认生时的个人报告不再被候选窗读取打死
 
 出生时间尚未 confirmed 时，报告会去读校正候选窗。那张表已经收回运行时表权限，读失败却被当成计算不可用，整份报告在排盘前就失败。现在改走只读 RPC；读不到窗口就按无窗口继续生成。Skill 版本未变。

docs/BUG_HISTORY.md

@@ -8228,3 +8228,19 @@
 - 相关记录：无
 - 复发自：无
 - 修复版本：待发布
+
+## BUG-533 | 开场打招呼被 set-focus 空 replace 清掉
+
+- 状态：resolved
+- 首次发现：2026-09-04
+- 最近更新：2026-09-04
+- 影响面：`applyStepAnswerChunk`、`retractSpoken`、开场轮 `answer.delta`
+- 用户现象：开场先流出「你好，很高兴一起做这次生时校正…」，页面最终只剩「我们慢慢来就好…」和采集题干。
+- 触发条件：模型在 `rectification-set-focus` 之前写出带句号的中文正文；该步已 `live` 播出。
+- 根因：任一公开工具的 `tool-call` 都会 `retractLive`，发出 `answer.delta` `{text:"", replace:true}`。set-focus 只是把题干挂到同一条消息，前面的打招呼不是过程自述。
+- 修复：`rectification-set-focus` 的 call/result 不再收回已播出正文。读诊断、记证据仍收回。
+- 验证：`rectification-step-answer`：打招呼 + set-focus 为 `none`，其后短句仍 `live`；read-diagnostics 仍 `retract`。
+- 防复发：set-focus 不得把同轮已播出的正文 replace 成空。不得把这个例外扩到 record/compare/diagnostics。
+- 相关记录：无
+- 复发自：无
+- 修复版本：待发布

frontend/src/lib/rectification-agentic/v9/step-answer.ts

@@ -6,7 +6,8 @@
  * Once the current step looks like the spoken reply — Chinese sentence end,
  * or live-unlock after compare/offer/result tools — tokens may stream as
  * `live`. A later public tool-call retracts that speculative stream so
- * "Let me set" never stays in `answer.delta`.
+ * "Let me set" never stays in `answer.delta`. Exception: `rectification-set-focus`
+ * only attaches the question stem; live greeting/handoff in the same step stays.
  */
 
 export type StepAnswerChunk = Readonly<{
@@ -45,6 +46,11 @@ const SPOKEN_LIVE_UNLOCK_TOOLS = new Set([
   "rectification-read-diagnostics",
 ]);
 
+/** set-focus writes the stem onto the same turn; it is not planning prose. */
+const KEEP_LIVE_SPOKEN_TOOLS = new Set([
+  "rectification-set-focus",
+]);
+
 function resetBuffers(state: StepAnswerState): void {
   state.text = "";
   state.pieces = [];
@@ -153,14 +159,19 @@ export function applyStepAnswerChunk(
     }
     case "tool-call":
       if (isPublicToolCall(chunk, isPublicTool)) {
-        const retracted = retractLive(state);
         state.calledTool = true;
+        if (KEEP_LIVE_SPOKEN_TOOLS.has(toolName(chunk))) return { kind: "none" };
+        const retracted = retractLive(state);
         return retracted.kind === "retract" ? retracted : { kind: "none" };
       }
       return { kind: "none" };
     case "tool-result":
     case "tool-error": {
       if (isPublicToolCall(chunk, isPublicTool)) state.calledTool = true;
+      if (KEEP_LIVE_SPOKEN_TOOLS.has(toolName(chunk))) {
+        resetBuffers(state);
+        return { kind: "none" };
+      }
       const discarded = state.calledTool || state.text.length > 0;
       const retracted = retractLive(state);
       resetBuffers(state);

frontend/tests/rectification-step-answer.test.ts

@@ -106,6 +106,42 @@ test("retracts a live spoken prefix if that step later calls a public tool", ()
   assert.deepEqual(spoken, { kind: "live", text: "诊断已经看过。接下来确认入职年份。" });
 });
 
+test("keeps a live opening greeting when the next public tool is set-focus", () => {
+  const state = createStepAnswerState();
+  assert.deepEqual(
+    applyStepAnswerChunk(
+      state,
+      chunk("text-delta", { text: "你好，我们从你最容易想起的经历开始就行。" }),
+      isPublicTool,
+    ),
+    { kind: "live", text: "你好，我们从你最容易想起的经历开始就行。" },
+  );
+  assert.equal(
+    applyStepAnswerChunk(
+      state,
+      chunk("tool-call", { toolName: "rectification-set-focus" }),
+      isPublicTool,
+    ).kind,
+    "none",
+  );
+  assert.equal(
+    applyStepAnswerChunk(
+      state,
+      chunk("tool-result", { toolName: "rectification-set-focus" }),
+      isPublicTool,
+    ).kind,
+    "none",
+  );
+  assert.deepEqual(
+    applyStepAnswerChunk(
+      state,
+      chunk("text-delta", { text: "我们慢慢来就好——想到哪件就聊哪件，不用一次说完。" }),
+      isPublicTool,
+    ),
+    { kind: "live", text: "我们慢慢来就好——想到哪件就聊哪件，不用一次说完。" },
+  );
+});
+
 test("does not live-publish English planning before a tool-call", () => {
   const state = createStepAnswerState();
   assert.equal(