feat(seo): integrate @nuxtjs/seo for basic SEO

This commit integrates the `@nuxtjs/seo` module to establish a baseline for search engine optimization.

Key changes include:
- Installation and configuration of the `@nuxtjs/seo` module.
- Definition of default meta tags for title, description, keywords, Open Graph, and Twitter cards.
- Addition of a default Open Graph image.
- Renaming of `robots.txt` to `_robots.txt` to align with the module's conventions for static file handling.

docs/design-doc-v1.md

@@ -3,6 +3,8 @@
 ### 🔹 品牌主轴：
 
 > 「一家融合创意与技术的定制开发工作室，专注于网站、软件、游戏与交互体验的全栈实现。」
+> A creative technology studio offering **custom development services**, specializing in full-stack solutions for websites, software, games, and interactive experiences.
+
 
 ### 🔹 品牌关键词：
 

nuxt.config.ts

@@ -1,8 +1,24 @@
+const DEFAULT_SEO = {
+  title: "Tootaio Studio",
+  description:
+    "A creative technology studio offering custom development services, specializing in full-stack solutions for websites, software, games, and interactive experiences.",
+  keywords:
+    "Tootaio, Tootaio Studio, custom development, full-stack solutions, web development, software development, game development, interactive experiences",
+  url: "https://tootaio.com",
+  image: "https://tootaio.com/og-image-1.png",
+};
+
 // https://nuxt.com/docs/api/configuration/nuxt-config
 export default defineNuxtConfig({
   compatibilityDate: "2025-07-15",
   devtools: { enabled: true },
-  modules: ["@nuxt/content", "@nuxt/ui", "@nuxt/eslint", "@nuxtjs/i18n"],
+  modules: [
+    "@nuxt/content",
+    "@nuxt/ui",
+    "@nuxt/eslint",
+    "@nuxtjs/i18n",
+    "@nuxtjs/seo",
+  ],
   css: ["@/assets/css/main.css"],
   i18n: {
     defaultLocale: "en",
@@ -21,4 +37,19 @@ export default defineNuxtConfig({
       },
     ],
   },
+  seo: {
+    meta: {
+      title: DEFAULT_SEO.title,
+      description: DEFAULT_SEO.description,
+      keywords: DEFAULT_SEO.keywords,
+      ogTitle: DEFAULT_SEO.title,
+      ogDescription: DEFAULT_SEO.description,
+      ogImage: DEFAULT_SEO.image,
+      ogUrl: DEFAULT_SEO.url,
+      twitterCard: "summary_large_image",
+      twitterTitle: DEFAULT_SEO.title,
+      twitterDescription: DEFAULT_SEO.description,
+      twitterImage: DEFAULT_SEO.image,
+    },
+  },
 });

package.json

@@ -14,6 +14,7 @@
     "@nuxt/eslint": "1.10.0",
     "@nuxt/ui": "4.1.0",
     "@nuxtjs/i18n": "10.2.0",
+    "@nuxtjs/seo": "3.2.2",
     "better-sqlite3": "^12.4.1",
     "eslint": "^9.39.0",
     "nuxt": "^4.2.0",