feat(seo): add sitemap, canonical metadata and legacy redirects

- Split the config into a createConfig(target) factory plus a thin .cn
  wrapper, so the two deployments differ in one place. The .cn build
  points canonical, hreflang, og:url, sitemap and robots at that origin,
  and omits social links that are not reachable from mainland China.
- Generate sitemap.xml and robots.txt per target. robots.txt is written
  at build time because one static file cannot carry the right origin for
  both domains.
- Emit per-page canonical, hreflang and Open Graph tags. og:title and
  friends are left to the theme, which already emits them and does not
  de-duplicate against site-level head entries.
- Redirect the retired /projects/ paths on Vercel, before the CN redirect
  so those visitors get a single hop.

rspress.cn.config.ts

@@ -0,0 +1,10 @@
+/**
+ * Build configuration for `onixbyte.cn`.
+ *
+ * Thin wrapper over the shared factory — see `rspress.config.ts` for what the
+ * `cn` target changes. Invoke it with `pnpm build:cn`, which passes this file
+ * via `rspress build --config`.
+ */
+import { createConfig } from "./rspress.config"
+
+export default createConfig("cn")

rspress.config.ts

@@ -1,44 +1,215 @@
 import * as path from "node:path"
+import { writeFile } from "node:fs/promises"
 import { defineConfig } from "@rspress/core"
+import type { RspressPlugin, SocialLink, UserConfig } from "@rspress/core"
+import { pluginSitemap } from "@rspress/plugin-sitemap"
+import { DOUYIN_ICON } from "./theme/lib/social-icons"
 
-export default defineConfig({
+/**
-  root: path.join(__dirname, "docs"),
+ * Which deployment this build targets.
-  title: "OnixByte",
+ *
-  icon: "/onixbyte-icon.svg",
+ * The two builds differ in more than colour: `onixbyte.cn` is hosted in
-  logo: {
+ * mainland China, so its build points every absolute URL at the `.cn` origin
-    light: "/onixbyte-light-logo.svg",
+ * and omits links to sites that are not reliably reachable from there.
-    dark: "/onixbyte-dark-logo.svg",
+ *
-  },
+ * Build with `pnpm build:com` / `pnpm build:cn` — see `package.json`. Both
-  themeConfig: {
+ * write to `doc_build`, so run and deploy them one at a time.
-    socialLinks: [
+ */
+export type SiteTarget = "com" | "cn"
+
+const ORIGINS: Record<SiteTarget, string> = {
+  com: "https://onixbyte.com",
+  cn: "https://onixbyte.cn",
+}
+
+/** Locale used for the unprefixed routes. */
+const DEFAULT_LANG = "en-gb"
+
+/** hreflang and Open Graph locale codes, keyed by Rspress lang. */
+const HREFLANG: Record<string, string> = { "en-gb": "en-GB", "zh-hans": "zh-Hans" }
+const OG_LOCALE: Record<string, string> = { "en-gb": "en_GB", "zh-hans": "zh_CN" }
+
+/**
+ * Social links, split by whether they are reliably reachable from mainland
+ * China. The `.cn` build renders only the `domestic` set.
+ *
+ * To move a link between builds, move it between these two arrays — nothing
+ * else needs to change.
+ */
+const SOCIAL_LINKS: Record<"domestic" | "international", SocialLink[]> = {
+  domestic: [
     {
       icon: "github",
       mode: "link",
-        content: "https://git.onixbyte.com/onixbyte/homepage",
+      content: "https://github.com/onixbyte-opensource",
     },
+    {
+      // Rspress has no preset Douyin icon, so the artwork is supplied inline —
+      // see `theme/lib/social-icons.ts` for the expected markup.
+      icon: { svg: DOUYIN_ICON },
+      mode: "link",
+      content: "https://v.douyin.com/8PlxMzXors0/",
+    },
+  ],
+  international: [
     {
       icon: "x",
       mode: "link",
       content: "https://x.com/onixbyte",
     },
   ],
+}
+
+/**
+ * Per-route sitemap priorities.
+ *
+ * `loc` is deliberately absent. The plugin builds a full entry (including `loc`)
+ * and then spreads `customMaps[routePath]` over it, so `loc` is genuinely
+ * optional — its own documentation shows entries without one. The published
+ * type nonetheless marks `loc` as required, so the assertion at the call site
+ * bridges that mismatch. `SitemapOverrides` is what keeps the priority values
+ * themselves checked.
+ */
+type CustomMapsOption = NonNullable<Parameters<typeof pluginSitemap>[0]["customMaps"]>
+type SitemapOverrides = Record<string, Omit<CustomMapsOption[string], "loc">>
+
+const SITEMAP_PRIORITIES = {
+  "/products/": { priority: "1.0" },
+  "/zh-hans/products/": { priority: "1.0" },
+  "/services/": { priority: "1.0" },
+  "/zh-hans/services/": { priority: "1.0" },
+  "/opensource-projects/": { priority: "0.8" },
+  "/zh-hans/opensource-projects/": { priority: "0.8" },
+} satisfies SitemapOverrides
+
+const localePrefix = (lang: string) => (lang === DEFAULT_LANG ? "" : `/${lang}`)
+
+/** Strips the language prefix, always returning a leading slash. */
+function bareRoutePath(routePath: string, lang: string): string {
+  const prefix = localePrefix(lang)
+  const rest = prefix && routePath.startsWith(prefix) ? routePath.slice(prefix.length) : routePath
+  return rest.startsWith("/") ? rest : `/${rest}`
+}
+
+/**
+ * Writes `robots.txt` at build time.
+ *
+ * It cannot live in `docs/public/`, because a single static file would have to
+ * carry the wrong origin for one of the two targets.
+ */
+function pluginRobots(origin: string): RspressPlugin {
+  return {
+    name: "plugin-onixbyte-robots",
+    async afterBuild(config: UserConfig) {
+      const outDir = path.resolve(process.cwd(), config.outDir ?? "doc_build")
+      const body = ["User-agent: *", "Allow: /", "", `Sitemap: ${origin}/sitemap.xml`, ""].join(
+        "\n"
+      )
+      await writeFile(path.join(outDir, "robots.txt"), body, "utf8")
+    },
+  }
+}
+
+export function createConfig(target: SiteTarget): UserConfig {
+  const origin = ORIGINS[target]
+  const socialLinks = [
+    ...SOCIAL_LINKS.domestic,
+    ...(target === "cn" ? [] : SOCIAL_LINKS.international),
+  ]
+
+  return defineConfig({
+    root: path.join(__dirname, "docs"),
+    title: "OnixByte",
+    description:
+      "OnixByte builds self-developed SaaS products and delivers custom software engineering services.",
+    icon: "/onixbyte-icon.svg",
+    logo: {
+      light: "/onixbyte-light-logo.svg",
+      dark: "/onixbyte-dark-logo.svg",
+    },
+    /**
+     * Per-route `<head>` additions.
+     *
+     * `og:title`, `og:description`, `description` and `og:type` are
+     * deliberately absent: the theme's `HeadTags` already emits them from the
+     * page title and site description, and site-level `head` entries do not
+     * take part in its de-duplication — adding them here would produce
+     * duplicate tags.
+     */
+    head: [
+      (route) => {
+        const canonical = `${origin}${route.routePath}`
+        const bare = bareRoutePath(route.routePath, route.lang)
+        const otherLang = route.lang === DEFAULT_LANG ? "zh-hans" : DEFAULT_LANG
+        const alternate = `${origin}${localePrefix(otherLang)}${bare === "/" ? "/" : bare}`
+        const defaultUrl = `${origin}${bare === "/" ? "/" : bare}`
+
+        return [
+          `<link rel="canonical" href="${canonical}">`,
+          `<link rel="alternate" hreflang="${HREFLANG[route.lang]}" href="${canonical}">`,
+          `<link rel="alternate" hreflang="${HREFLANG[otherLang]}" href="${alternate}">`,
+          `<link rel="alternate" hreflang="x-default" href="${defaultUrl}">`,
+          `<meta property="og:url" content="${canonical}">`,
+          `<meta property="og:site_name" content="OnixByte">`,
+          `<meta property="og:locale" content="${OG_LOCALE[route.lang]}">`,
+          `<meta property="og:image" content="${origin}/og-image.png">`,
+          `<meta name="twitter:card" content="summary_large_image">`,
+        ].join("")
+      },
+    ],
+    themeConfig: {
+      // NOTE: `footer` is intentionally not set — the site footer is the
+      // `SiteFooter` component wired through the Layout `bottom` slot. Setting
+      // `footer.message` here would render the built-in `HomeFooter` on top of
+      // it on the home page only.
+      //
+      // `nav` and `sidebar` are also intentionally not set: supplying either
+      // switches off auto-generation and would make every `_nav.json` and
+      // `_meta.json` inert.
+      socialLinks,
+      lastUpdated: true,
     },
     markdown: {
       showLineNumbers: true,
     },
-  lang: "en-gb",
+    lang: DEFAULT_LANG,
     locales: [
       {
         lang: "en-gb",
         label: "English (Great Britain)",
         title: "OnixByte",
-      description: "OnixByte Official",
+        description:
+          "OnixByte builds self-developed SaaS products and delivers custom software engineering services.",
       },
       {
         lang: "zh-hans",
         label: "简体中文",
         title: "OnixByte",
-      description: "OnixByte 官方站点",
+        description: "曜珀科技自主研发 SaaS 产品，并提供定制化软件开发服务。",
       },
     ],
-})
+    // Local full-text search. This is already the Rspress v2 default; stated
+    // explicitly so the intent is visible. The index is emitted per locale to
+    // `static/search_index.<lang>.<hash>.json` at build time.
+    search: {
+      mode: "local",
+      codeBlocks: true,
+    },
+    plugins: [
+      pluginSitemap({
+        siteUrl: origin,
+        defaultChangeFreq: "weekly",
+        defaultPriority: "0.5",
+        // Keys are full route paths, so the non-default locale needs its own
+        // entries — `/products/` does not match `/zh-hans/products/`.
+        // Double assertion rather than a plain cast: the plugin's `Sitemap` type
+        // requires `loc`, so the two types do not overlap enough for a single
+        // assertion. See `SITEMAP_PRIORITIES` above for why omitting it is right.
+        customMaps: SITEMAP_PRIORITIES as unknown as CustomMapsOption,
+      }),
+      pluginRobots(origin),
+    ],
+  })
+}
+
+export default createConfig("com")

vercel.json

@@ -1,6 +1,26 @@
 {
   "outputDirectory": "doc_build",
   "redirects": [
+    {
+      "source": "/zh-hans/projects",
+      "destination": "/zh-hans/opensource-projects/",
+      "permanent": true
+    },
+    {
+      "source": "/zh-hans/projects/:path*",
+      "destination": "/zh-hans/opensource-projects/:path*",
+      "permanent": true
+    },
+    {
+      "source": "/projects",
+      "destination": "/opensource-projects/",
+      "permanent": true
+    },
+    {
+      "source": "/projects/:path*",
+      "destination": "/opensource-projects/:path*",
+      "permanent": true
+    },
     {
       "source": "/:path(.*)",
       "has": [