feat: add Traditional Chinese (zh-TW) support on dashboard

web/src/components/LanguageSwitcher.tsx

@@ -4,12 +4,16 @@ import { useI18n } from "@/i18n/context";
 
 /**
  * Compact language toggle — shows a clickable flag that switches between
- * English and Chinese.  Persists choice to localStorage.
+ * English, Simplified Chinese, and Traditional Chinese.  Persists choice to localStorage.
  */
 export function LanguageSwitcher() {
   const { locale, setLocale, t } = useI18n();
 
-  const toggle = () => setLocale(locale === "en" ? "zh" : "en");
+  const toggle = () => {
+    if (locale === "en") setLocale("zh");
+    else if (locale === "zh") setLocale("tw");
+    else setLocale("en");
+  };
 
   return (
     <Button
@@ -21,14 +25,13 @@ export function LanguageSwitcher() {
     >
       <span className="inline-flex items-center gap-1.5">
         <span className="text-base leading-none">
-          {locale === "en" ? "🇬🇧" : "🇨🇳"}
+          {locale === "en" ? "🇬🇧" : locale === "zh" ? "🇨🇳" : "🇹🇼"}
         </span>
-
         <Typography
           mondwest
           className="hidden sm:inline tracking-wide uppercase text-[0.65rem]"
         >
-          {locale === "en" ? "EN" : "中文"}
+          {locale === "en" ? "EN" : locale === "zh" ? "简体" : "繁體"}
         </Typography>
       </span>
     </Button>

web/src/i18n/context.tsx

@@ -2,14 +2,15 @@ import { createContext, useContext, useState, useCallback, type ReactNode } from
 import type { Locale, Translations } from "./types";
 import { en } from "./en";
 import { zh } from "./zh";
+import { tw } from "./tw";
 
-const TRANSLATIONS: Record<Locale, Translations> = { en, zh };
+const TRANSLATIONS: Record<Locale, Translations> = { en, zh, tw };
 const STORAGE_KEY = "hermes-locale";
 
 function getInitialLocale(): Locale {
   try {
     const stored = localStorage.getItem(STORAGE_KEY);
-    if (stored === "en" || stored === "zh") return stored;
+    if (stored === "en" || stored === "zh" || stored === "tw") return stored;
   } catch {
     // SSR or privacy mode
   }

web/src/i18n/en.ts

@@ -419,7 +419,7 @@ export const en: Translations = {
   },
 
   language: {
-    switchTo: "Switch to Chinese",
+    switchTo: "Switch language",
   },
 
   theme: {