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

src/components/Subtitles.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { ref, watch } from 'vue'
+import { ref, watch, computed } from 'vue'
 
 interface SubCue {
   start: number
@@ -10,20 +10,25 @@ interface SubCue {
 const props = defineProps<{
   currentTime: number
   subtitleUrl: string | null
+  subtitles?: Record<string, string> | null
+  lang?: string
 }>()
 
 const cues = ref<SubCue[]>([])
 const currentText = ref('')
 const loadedUrl = ref('')
 
-watch(() => props.subtitleUrl, async (url) => {
+const effectiveUrl = computed(() => {
+  if (props.lang && props.subtitles?.[props.lang]) return props.subtitles[props.lang]
+  return props.subtitleUrl
+})
+
+watch(effectiveUrl, async (url) => {
   if (!url) {
     cues.value = []
-    currentText.value = ''
     loadedUrl.value = ''
     return
   }
-  if (url === loadedUrl.value) return
   loadedUrl.value = url
   try {
     const resp = await fetch(url)