feat: i18n system, lang switch component, english subtitles, UI improvements, roadmap update

src/components/PlaybackBar.vue

@@ -1,5 +1,8 @@
 <script setup lang="ts">
 import { ref, watch, onMounted } from 'vue'
+import { useI18n } from '@/composables/useI18n'
+
+const { t } = useI18n()
 
 const props = defineProps<{
   canSkip: boolean
@@ -29,7 +32,7 @@ onMounted(() => updateLabel(props.currentSpeed))
 
 <template>
   <div class="playback-bar">
-    <button v-if="canSkip" class="pb-btn skip-btn" @click="emit('skip')">跳过</button>
+    <button v-if="canSkip" class="pb-btn skip-btn" @click="emit('skip')">{{ t('ui.skip') }}</button>
     <button class="pb-btn speed-btn" @click="toggleSpeed">{{ speedLabel }}</button>
   </div>
 </template>