fix(scripts): preserve emoji in GitHub API errors (#108184)

* fix(scripts): keep GitHub errors valid Unicode

* style(scripts): format GitHub error boundary test

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

scripts/gh-read.ts

@@ -4,6 +4,7 @@ import { createPrivateKey, createSign } from "node:crypto";
 import { pathToFileURL } from "node:url";
 import { readSecretFileSync } from "@openclaw/fs-safe/secret";
 import { expectDefined } from "../packages/normalization-core/src/expect.js";
+import { truncateUtf16Safe } from "../packages/normalization-core/src/utf16-slice.js";
 import { readBoundedResponseText } from "./lib/bounded-response.ts";
 import { parseStrictIntegerOption } from "./lib/dev-tooling-safety.ts";
 import {
@@ -238,7 +239,7 @@ export async function readBoundedGitHubErrorText(
 
       text += decoder.decode(value, { stream: true });
       if (text.length > maxChars) {
-        text = text.slice(0, maxChars);
+        text = truncateUtf16Safe(text, maxChars);
         truncated = true;
         break;
       }

test/scripts/gh-read.test.ts

@@ -173,6 +173,26 @@ describe("gh-read helpers", () => {
     expect(text.length).toBeLessThan(4200);
   });
 
+  it.each([
+    {
+      caseName: "drops a split surrogate pair",
+      responseBody: `abc\u{1f600}tail`,
+      expectedText: "abc\n[truncated]",
+    },
+    {
+      caseName: "preserves a complete surrogate pair",
+      responseBody: `ab\u{1f600}tail`,
+      expectedText: `ab\u{1f600}\n[truncated]`,
+    },
+  ])(
+    "keeps GitHub API error truncation UTF-16 safe: $caseName",
+    async ({ responseBody, expectedText }) => {
+      const response = new Response(responseBody, { status: 500 });
+
+      await expect(readBoundedGitHubErrorText(response, 4)).resolves.toBe(expectedText);
+    },
+  );
+
   it("reads bounded GitHub API JSON responses", async () => {
     await expect(readBoundedGitHubJson(new Response('{"id":123}'), 1024)).resolves.toEqual({
       id: 123,