feat: add trusted mirror update source

Version checks and downloads previously depended on GitHub Release. About & Updates now offers GitHub or a validated mirror source, keeps the selector beneath the startup-check switch, and disables it when startup checks are off.

The website resolves platform downloads from a bounded OSS release index with a GitHub fallback. Tagged releases publish and verify immutable OSS assets through OIDC before switching the latest-version index; deployment requires the configured Alibaba Cloud environment variables and role.

Release note: “关于与更新”新增 GitHub 与镜像节点选择，启动检查、手动检查和下载页使用同一可信来源；官网下载也可按系统、架构和安装包类型直接选择。

build/verify-site-release.cjs

@@ -0,0 +1,63 @@
+const { readFileSync } = require('node:fs')
+const { resolve } = require('node:path')
+
+function parseArguments(argv) {
+  if (argv.length !== 2 || argv[0] !== '--manifest' || !argv[1]) {
+    throw new Error('必须指定 --manifest')
+  }
+  return { manifest: resolve(argv[1]) }
+}
+
+async function verifySiteRelease(manifest, request = fetch) {
+  const files = Object.values(manifest?.targets ?? {}).flatMap(
+    (target) => Object.values(target?.files ?? {})
+  )
+  if (files.length !== 12) {
+    throw new Error(`官网发布文件数量错误：${files.length}`)
+  }
+  const urls = new Set()
+  for (const file of files) {
+    if (
+      typeof file?.url !== 'string' ||
+      !Number.isSafeInteger(file.size) ||
+      file.size < 1 ||
+      urls.has(file.url)
+    ) {
+      throw new Error('官网发布文件元数据无效')
+    }
+    urls.add(file.url)
+    const response = await request(file.url, {
+      method: 'HEAD',
+      redirect: 'error'
+    })
+    if (!response.ok) {
+      throw new Error(`OSS 文件不可访问：${file.url}（${response.status}）`)
+    }
+    const contentLength = Number(response.headers.get('content-length'))
+    if (contentLength !== file.size) {
+      throw new Error(
+        `OSS 文件大小不匹配：${file.url}，期望 ${file.size}，实际 ${contentLength}`
+      )
+    }
+  }
+  return files.length
+}
+
+async function main(argv = process.argv.slice(2)) {
+  const options = parseArguments(argv)
+  const manifest = JSON.parse(readFileSync(options.manifest, 'utf8'))
+  const count = await verifySiteRelease(manifest)
+  console.log(`OSS 发布文件验证通过：${count} 个`)
+}
+
+module.exports = {
+  parseArguments,
+  verifySiteRelease
+}
+
+if (require.main === module) {
+  main().catch((error) => {
+    console.error(error)
+    process.exitCode = 1
+  })
+}