加一套抓真实请求做预设对比的工具，并把三份预设的机制差异记进 README。

tools/st-request-diff/extract-preset.mjs

@@ -0,0 +1,25 @@
+// 从本仓库存的预设包里把原始酒馆 JSON 抠出来，两边用同一个文件。
+// 用法: node extract-preset.mjs [预设包路径] [输出名]
+import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const HERE = path.dirname(fileURLToPath(import.meta.url));
+const input =
+  process.argv[2] ??
+  path.join(os.homedir(), ".writing-agent", "presets", "linux_1-3-9c636433.json");
+const name = process.argv[3] ?? "linux_1-3";
+
+const pkg = JSON.parse(readFileSync(input, "utf8"));
+const raw = pkg.raw ?? pkg;
+if (!raw.prompts || !raw.prompt_order) {
+  throw new Error("这份预设里没有 prompts / prompt_order，不是酒馆格式");
+}
+raw.name = name;
+
+const outDir = path.join(HERE, "presets");
+mkdirSync(outDir, { recursive: true });
+const file = path.join(outDir, name + ".json");
+writeFileSync(file, JSON.stringify(raw, null, 2), "utf8");
+console.log("写出 " + file + " (prompts=" + raw.prompts.length + ", prompt_order=" + raw.prompt_order.length + ")");