预设兼容：按真实抓包对齐装配与包装层，补上声明式工具与预设正则。

- 装配只认 prompt_order.enabled；squash_system_messages 只合并相邻 system（新增 system 档，连接符按酒馆用单换行）
- 包装层：new_chat_prompt、示例对话（new_example_chat_prompt + <START> 切段 + name）、角色卡三块与 personality_format/scenario_format、{{user}}/{{char}} 取值、任务契约并进预设条目
- 工具协议：按 ToolBindings / 伪工具协议数据声明真 tools（presetToolPolicy=preset），工具描述用到的条目不再重复作为消息发出
- 正则：promptOnly 作用于对话历史（含 depth 过滤）、写入时脚本改写回复；{{//}} 注释按配平扫描
- tools/st-request-diff：真假上游抓包对比工具、三份预设的机制结论与实测报告

tests/dialogue-history.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
   appendDialogueHistoryTurn,
+  parseHistoryMessages,
   projectDialogueHistory,
   buildHistoryFallback,
   isDialogueHistoryRef,
@@ -14,18 +15,78 @@ import {
   synthesizeContextOrderFromWorkers,
 } from "../src/skills/context-order.js";
 
+describe("parseHistoryMessages", () => {
+  it("turns ## 用户 / ## 助手 blocks into real turns", () => {
+    const raw = appendDialogueHistoryTurn(
+      appendDialogueHistoryTurn("", { role: "助手", text: "门开了。" }),
+      { role: "用户", text: "我推门。" },
+    );
+    expect(parseHistoryMessages(raw)).toEqual([
+      { role: "assistant", content: "门开了。" },
+      { role: "user", content: "我推门。" },
+    ]);
+  });
+
+  it("accepts 【用户】 and 用户：single-line forms", () => {
+    expect(parseHistoryMessages("【用户】\n你好\n\n【助手】\n在。")).toEqual([
+      { role: "user", content: "你好" },
+      { role: "assistant", content: "在。" },
+    ]);
+    expect(parseHistoryMessages("用户：你好\n助手：在。")).toEqual([
+      { role: "user", content: "你好" },
+      { role: "assistant", content: "在。" },
+    ]);
+  });
+
+  it("keeps the projection note on the first turn", () => {
+    const turns = parseHistoryMessages(
+      "（仅最近 20 段，更早已省略）\n\n## 用户\n\n你好",
+    );
+    expect(turns).toHaveLength(1);
+    expect(turns[0]!.content).toContain("仅最近");
+    expect(turns[0]!.content).toContain("你好");
+  });
+
+  it("returns [] for text without role markers", () => {
+    expect(parseHistoryMessages("一段无结构的前情提要")).toEqual([]);
+  });
+
+  it("keeps a body line that looks like markdown heading", () => {
+    const raw = "## 用户\n\n我说## 这不是块头\n\n## 助手\n\n嗯";
+    const turns = parseHistoryMessages(raw);
+    expect(turns).toHaveLength(2);
+    expect(turns[0]!.content).toContain("这不是块头");
+  });
+});
+
 describe("dialogue history projection", () => {
   it("recognizes history refs and projects by level", () => {
     expect(isDialogueHistoryRef("对话.历史")).toBe(true);
     expect(isDialogueHistoryRef("history")).toBe(true);
-    const long = Array.from({ length: 30 }, (_, i) => `## 用户\n\n第${i}句`).join(
+    const long = Array.from({ length: 60 }, (_, i) => `## 用户\n\n第${i}句`).join(
       "\n\n",
     );
     const summary = projectDialogueHistory(long, "summary");
     expect(summary).toContain("仅最近");
+    // 裁到 n 段（summary = 20）
+    expect(summary.split("## 用户").length - 1).toBe(20);
     expect(projectDialogueHistory(long, "fixed")).toContain("不注入");
   });
 
+  it("keeps the whole window until it doubles（滞回，不每轮位移）", () => {
+    const turn = (n: number) =>
+      Array.from({ length: n }, (_, i) => `## 用户\n\n第${i}句`).join("\n\n");
+    // 20～40 段（summary 的 n=20，高水位=40）原样全给，前缀稳定
+    expect(projectDialogueHistory(turn(30), "summary")).not.toContain("仅最近");
+    expect(projectDialogueHistory(turn(30), "summary").split("## 用户").length - 1).toBe(
+      30,
+    );
+    // 超过高水位才裁，且一次裁到 20
+    expect(projectDialogueHistory(turn(41), "summary").split("## 用户").length - 1).toBe(
+      20,
+    );
+  });
+
   it("assembles history tag in flat segment order", () => {
     const bb = new Blackboard();
     bb.write({