fix: harden backend stability and test production utilities

backend/tests/archive-tests.js

@@ -0,0 +1,31 @@
+const assert = require('assert');
+const { PassThrough } = require('stream');
+const { finished } = require('stream/promises');
+const { createZipArchive } = require('../utils/archive');
+
+async function run() {
+  const archive = await createZipArchive({ store: true });
+  const output = new PassThrough();
+  const chunks = [];
+  output.on('data', (chunk) => chunks.push(chunk));
+  archive.pipe(output);
+  archive.append(Buffer.from('wanwanyun archive smoke test'), { name: 'smoke.txt' });
+
+  await archive.finalize();
+  await finished(output);
+
+  const zip = Buffer.concat(chunks);
+  assert.ok(zip.length > 30, 'ZIP output should not be empty');
+  assert.strictEqual(zip.subarray(0, 2).toString('ascii'), 'PK');
+  assert.ok(zip.includes(Buffer.from('smoke.txt')), 'ZIP should contain the requested entry');
+
+  console.log('通过: 1');
+  console.log('失败: 0');
+}
+
+run().catch((error) => {
+  console.error(error.stack || error.message);
+  console.log('通过: 0');
+  console.log('失败: 1');
+  process.exit(1);
+});