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/message-squash.test.ts

@@ -0,0 +1,109 @@
+import { describe, expect, it } from "vitest";
+import type { ChatMessage } from "../src/llm/client.js";
+import { squashMessages } from "../src/llm/message-squash.js";
+
+const sys = (content: string): ChatMessage => ({ role: "system", content });
+const user = (content: string): ChatMessage => ({ role: "user", content });
+const asst = (content: string): ChatMessage => ({ role: "assistant", content });
+
+const toolCall: ChatMessage = {
+  role: "assistant",
+  content: null,
+  tool_calls: [
+    { id: "1", type: "function", function: { name: "t", arguments: "{}" } },
+  ],
+};
+const toolResult: ChatMessage = { role: "tool", content: "{}", tool_call_id: "1" };
+
+describe("squashMessages", () => {
+  it("none returns the list untouched", () => {
+    const input = [sys("a"), sys("b")];
+    expect(squashMessages(input, "none")).toBe(input);
+  });
+
+  it("merge joins adjacent same-role messages with a blank line", () => {
+    const out = squashMessages([sys("a"), sys("b"), user("c")], "merge");
+    expect(out).toEqual([sys("a\n\nb"), user("c")]);
+  });
+
+  it("merge keeps role changes intact", () => {
+    const out = squashMessages([sys("a"), user("b"), asst("c")], "merge");
+    expect(out.map((m) => m.role)).toEqual(["system", "user", "assistant"]);
+  });
+
+  it("never merges tool groups", () => {
+    const out = squashMessages(
+      [sys("a"), sys("b"), toolCall, toolResult, asst("x"), asst("y")],
+      "merge",
+    );
+    expect(out.map((m) => m.role)).toEqual([
+      "system",
+      "assistant",
+      "tool",
+      "assistant",
+    ]);
+    // 工具组原样保留
+    expect(out[1]).toBe(toolCall);
+    expect(out[2]).toBe(toolResult);
+  });
+
+  it("semi folds system into neighbouring messages", () => {
+    const out = squashMessages(
+      [sys("规则"), user("问题"), sys("补充"), asst("回答")],
+      "semi",
+    );
+    expect(out).toEqual([user("规则\n\n问题"), asst("补充\n\n回答")]);
+  });
+
+  it("strict makes the first message a user", () => {
+    const out = squashMessages([asst("前言"), user("问题")], "strict");
+    expect(out[0]?.role).toBe("user");
+    expect(out[0]?.content).toBe("前言\n\n问题");
+  });
+
+  it("single-user-turn collapses everything into one user message", () => {
+    const out = squashMessages(
+      [sys("规则"), user("问题"), asst("回答")],
+      "single-user-turn",
+    );
+    expect(out).toEqual([user("规则\n\n问题\n\n回答")]);
+  });
+
+  it("falls back to merge when a tool group is present", () => {
+    const out = squashMessages(
+      [sys("a"), sys("b"), toolCall, toolResult],
+      "single-user-turn",
+    );
+    expect(out.map((m) => m.role)).toEqual(["system", "assistant", "tool"]);
+    expect(out[0]?.content).toBe("a\n\nb");
+  });
+
+  it("handles empty input", () => {
+    expect(squashMessages([], "strict")).toEqual([]);
+  });
+});
+
+describe("system 档（对齐酒馆 squashSystemMessages）", () => {
+  it("只合并相邻 system，user/assistant 不动", () => {
+    const out = squashMessages(
+      [sys("a"), sys("b"), user("u1"), user("u2"), asst("c1"), asst("c2"), sys("d"), sys("e")],
+      "system",
+    );
+    expect(out).toEqual([
+      sys("a\nb"),
+      user("u1"),
+      user("u2"),
+      asst("c1"),
+      asst("c2"),
+      sys("d\ne"),
+    ]);
+  });
+
+  it("不碰工具组", () => {
+    const out = squashMessages(
+      [sys("a"), sys("b"), toolCall, toolResult, sys("c"), sys("d")],
+      "system",
+    );
+    expect(out.map((m) => m.role)).toEqual(["system", "assistant", "tool", "system"]);
+  });
+});