fix: resolve TypeScript compilation errors

Fixes:
- VideoPlayer.vue: restore allTags, filteredMarks, marksByTag (removed by mistake)
- PeopleView.vue: fix frameTime scope in playFaceDetailVideo catch block
- Both errors caused white screen on build failure

Root cause:
1. visibleTags duplicate declaration (old + new logic)
2. frameTime undefined in catch block (scope issue)

Solution:
1. Keep allTags/filteredMarks/marksByTag (needed in template)
2. Keep visibleTags (new logic for processor toggles)
3. Move frameTime calculation to correct scope in catch block

src/locales/index.ts

@@ -0,0 +1,77 @@
+import { createI18n } from 'vue-i18n'
+import en from './en.json'
+import zhTW from './zh-TW.json'
+
+export type MessageSchema = typeof en
+
+const supportedLanguages = {
+  'en': en,
+  'zh-TW': zhTW,
+}
+
+function detectInitialLanguage(): string {
+  const saved = localStorage.getItem('app_language')
+  if (saved && saved in supportedLanguages) {
+    return saved
+  }
+  
+  if (saved === 'auto') {
+    return detectOSLanguage()
+  }
+  
+  return 'en'
+}
+
+function detectOSLanguage(): string {
+  let osLang = 'en'
+  
+  try {
+    if ((window as any).__TAURI__) {
+      const locale = (window as any).__TAURI__?.os?.getLocale?.()
+      if (locale) osLang = locale
+    } else {
+      osLang = navigator.language || 'en'
+    }
+  } catch (e) {
+    console.error('Language detection failed:', e)
+  }
+  
+  if (osLang.startsWith('zh-TW') || osLang.startsWith('zh-Hant')) {
+    return 'zh-TW'
+  } else if (osLang.startsWith('zh-CN') || osLang.startsWith('zh-Hans')) {
+    return 'zh-CN'
+  } else if (osLang.startsWith('ja')) {
+    return 'ja'
+  } else if (osLang.startsWith('ko')) {
+    return 'ko'
+  }
+  
+  return 'en'
+}
+
+const i18n = createI18n<[MessageSchema], 'en' | 'zh-TW'>({
+  legacy: false,
+  locale: detectInitialLanguage(),
+  fallbackLocale: 'en',
+  messages: supportedLanguages as any,
+  missingWarn: false,
+  fallbackWarn: false,
+})
+
+export function changeLanguage(lang: string) {
+  if (lang === 'auto') {
+    localStorage.setItem('app_language', 'auto')
+    const detected = detectOSLanguage()
+    i18n.global.locale = detected as any
+  } else {
+    localStorage.setItem('app_language', lang)
+    i18n.global.locale = lang as any
+  }
+}
+
+export function getCurrentLanguage(): string {
+  return i18n.global.locale as string
+}
+
+export { detectOSLanguage }
+export default i18n