chore: 将前端移动到 client/ 目录，准备合并为单仓库

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

client/src/main.ts

@@ -0,0 +1,59 @@
+import { createApp } from "vue"
+import { create } from "naive-ui"
+import App from "./App.vue"
+import "./global.css"
+import { addAPIProvider } from "@iconify/vue"
+
+//@ts-ignore
+import "github-markdown-css/github-markdown-light.css"
+
+import { marked } from "marked"
+import alert from "marked-alert"
+import { markedHighlight } from "marked-highlight"
+import preview from "marked-code-preview"
+import { alertVariants } from "./utils/const"
+
+import hljs from "highlight.js/lib/core"
+import xml from "highlight.js/lib/languages/xml"
+import css from "highlight.js/lib/languages/css"
+import javascript from "highlight.js/lib/languages/javascript"
+import plaintext from "highlight.js/lib/languages/plaintext"
+//@ts-ignore
+import "highlight.js/styles/github.min.css"
+import { router } from "./router"
+
+hljs.registerLanguage("html", xml)
+hljs.registerLanguage("css", css)
+hljs.registerLanguage("js", javascript)
+hljs.registerLanguage("javascript", javascript)
+hljs.registerLanguage("plaintext", plaintext)
+
+marked.use({
+  gfm: true,
+})
+marked.use(
+  markedHighlight({
+    langPrefix: "hljs language-",
+    highlight(code, lang) {
+      const language = hljs.getLanguage(lang) ? lang : "plaintext"
+      return hljs.highlight(code, { language }).value
+    },
+  }),
+)
+marked.use(alert({ variants: alertVariants }))
+
+const template = `<div class="markedown-body-preview">{preview}</div>`
+marked.use(preview({ template }))
+
+const app = createApp(App)
+const naive = create()
+
+app.use(naive)
+app.use(router)
+app.mount("#app")
+
+if (!!import.meta.env.PUBLIC_ICONIFY_URL) {
+  addAPIProvider("", {
+    resources: [import.meta.env.PUBLIC_ICONIFY_URL],
+  })
+}