chore: 删除无用的预检测试脚本 _preflight.js

该脚本仅用于本地测试，不属于项目核心代码，清理冗余文件减少项目杂乱度

_preflight.js

@@ -1,53 +0,0 @@
-const https = require('https');
-const base = 'test-test.zeabur.app';
-
-function req(method, path, headers) {
-  return new Promise((resolve) => {
-    const r = https.request({
-      hostname: base, port: 443, path, method, headers: headers || {},
-    }, (res) => {
-      const chunks = [];
-      res.on('data', (c) => chunks.push(c));
-      res.on('end', () => resolve({ status: res.statusCode, headers: res.headers, body: Buffer.concat(chunks) }));
-    });
-    r.on('error', (e) => resolve({ error: e.message }));
-    r.end();
-  });
-}
-
-(async () => {
-  // 1. 预检 OPTIONS 请求
-  console.log('=== 预检: OPTIONS /v1/audio/speech (with Origin) ===');
-  const r1 = await req('OPTIONS', '/v1/audio/speech', {
-    'Origin': 'https://example.com',
-    'Access-Control-Request-Method': 'POST',
-    'Access-Control-Request-Headers': 'content-type, authorization',
-  });
-  console.log('Status:', r1.status);
-  console.log('Headers:');
-  for (const k of Object.keys(r1.headers)) {
-    if (k.startsWith('access-control') || k === 'vary') {
-      console.log('  ' + k + ': ' + r1.headers[k]);
-    }
-  }
-  console.log('Body:', r1.body ? r1.body.toString('utf8') : '');
-
-  // 2. 预检但无 Origin(同源或非浏览器)
-  console.log('\n=== OPTIONS /v1/audio/speech (NO Origin) ===');
-  const r2 = await req('OPTIONS', '/v1/audio/speech', {});
-  console.log('Status:', r2.status);
-
-  // 3. 实际 POST 请求
-  console.log('\n=== POST /v1/audio/speech (with Origin) ===');
-  const body = JSON.stringify({ model: 'tts-1', input: 'test', voice: 'alloy' });
-  const r3 = await req('POST', '/v1/audio/speech', {
-    'Origin': 'https://example.com',
-    'Content-Type': 'application/json',
-    'Authorization': 'Bearer sk-HRNfl15pp8e0KLewaydRCmvf2KfkOYd728yLJmuff5DkyaXd',
-    'Content-Length': Buffer.byteLength(body),
-  });
-  if (r3.body) r3.write = r3.write || (() => {});
-  console.log('Status:', r3.status);
-  console.log('Access-Control-Allow-Origin:', r3.headers['access-control-allow-origin']);
-  console.log('Vary:', r3.headers['vary']);
-})();