feat(frontend): Shiki 白名单语言高亮并支持 aardio

显式加载常用语言；修复 pretty-code 去 shiki class 导致不上色，以及 aardio 循环别名。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/components/markdown/shikiHighlighter.ts

@@ -0,0 +1,116 @@
+import { createHighlighterCore, type HighlighterCore } from "shiki/core";
+import { createOnigurumaEngine } from "shiki/engine/oniguruma";
+import { aardioGrammar } from "./aardioGrammar";
+
+/** 站点 Markdown 代码高亮：显式白名单（非全量） */
+export const SHIKI_LANG_IDS = [
+  "go",
+  "python",
+  "r",
+  "markdown",
+  "javascript",
+  "typescript",
+  "tsx",
+  "jsx",
+  "json",
+  "yaml",
+  "toml",
+  "bash",
+  "sql",
+  "html",
+  "css",
+  "scss",
+  "diff",
+  "plaintext",
+] as const;
+
+export type SiteShikiLang = (typeof SHIKI_LANG_IDS)[number] | "aardio";
+
+export const SHIKI_LANG_ALIAS: Record<string, string> = {
+  py: "python",
+  md: "markdown",
+  js: "javascript",
+  ts: "typescript",
+  sh: "bash",
+  shell: "bash",
+  zsh: "bash",
+  yml: "yaml",
+  text: "plaintext",
+  txt: "plaintext",
+};
+
+export const SHIKI_THEMES = {
+  light: "github-light",
+  dark: "github-dark-dimmed",
+} as const;
+
+const ALLOWED = new Set<string>([...SHIKI_LANG_IDS, "aardio"]);
+
+/** 未知语言降级为 plaintext；别名归一到白名单 id */
+export function resolveShikiLang(raw?: string | null): SiteShikiLang {
+  const id = (raw || "").trim().toLowerCase();
+  if (!id) return "plaintext";
+  const mapped = SHIKI_LANG_ALIAS[id] || id;
+  if (ALLOWED.has(mapped)) return mapped as SiteShikiLang;
+  return "plaintext";
+}
+
+let highlighterPromise: Promise<HighlighterCore> | null = null;
+
+/** 站点单例 highlighter：仅白名单语言 + aardio */
+export function getSiteHighlighter(): Promise<HighlighterCore> {
+  if (!highlighterPromise) {
+    highlighterPromise = createHighlighterCore({
+      themes: [
+        import("@shikijs/themes/github-light"),
+        import("@shikijs/themes/github-dark-dimmed"),
+      ],
+      langs: [
+        import("@shikijs/langs/go"),
+        import("@shikijs/langs/python"),
+        import("@shikijs/langs/r"),
+        import("@shikijs/langs/markdown"),
+        import("@shikijs/langs/javascript"),
+        import("@shikijs/langs/typescript"),
+        import("@shikijs/langs/tsx"),
+        import("@shikijs/langs/jsx"),
+        import("@shikijs/langs/json"),
+        import("@shikijs/langs/yaml"),
+        import("@shikijs/langs/toml"),
+        import("@shikijs/langs/bash"),
+        import("@shikijs/langs/sql"),
+        import("@shikijs/langs/html"),
+        import("@shikijs/langs/css"),
+        import("@shikijs/langs/scss"),
+        import("@shikijs/langs/diff"),
+        // plaintext / text / txt 为 Shiki 特殊语言，无需 grammar
+        aardioGrammar,
+      ],
+      langAlias: SHIKI_LANG_ALIAS,
+      engine: createOnigurumaEngine(import("shiki/wasm")),
+    });
+  }
+  return highlighterPromise;
+}
+
+/** 客户端/工具：按白名单高亮为双主题 HTML */
+export async function siteCodeToHtml(code: string, langRaw?: string | null): Promise<string> {
+  const highlighter = await getSiteHighlighter();
+  const lang = resolveShikiLang(langRaw);
+  return highlighter.codeToHtml(code, {
+    lang,
+    themes: {
+      light: SHIKI_THEMES.light,
+      dark: SHIKI_THEMES.dark,
+    },
+    defaultColor: false,
+  });
+}
+
+/**
+ * 供 rehype-pretty-code 的 getHighlighter：
+ * 忽略其默认 langs:['plaintext']，始终返回站点白名单单例。
+ */
+export async function getPrettyCodeHighlighter(): Promise<HighlighterCore> {
+  return getSiteHighlighter();
+}