fix: chapter list follows JSON order, remember last selected chapter

src/components/StoryGallery.vue

@@ -109,31 +109,19 @@ function endingStatus(endingId: string) {
   return props.visitedIds.has(props.endings.find(e => e.id === endingId)?.sceneId ?? '')
 }
 
-function chaptersByProgress() {
-  return [...props.chapters].sort((a, b) => {
-    const pa = chapterProgress(a.id).pct
-    const pb = chapterProgress(b.id).pct
-    return pb - pa
-  })
+function resolveInitialChapter(): string {
+  const saved = localStorage.getItem('story_chapter')
+  if (saved && props.chapters.some(c => c.id === saved)) return saved
+  const first = props.chapters[0]
+  return first?.id ?? ''
 }
 
-const defaultChapter = computed(() => {
-  const sorted = chaptersByProgress()
-  for (const ch of sorted) {
-    if (chapterProgress(ch.id).pct > 0) return ch
-  }
-  return sorted[0] ?? null
-})
-
-const currentChapterId = ref<string>('')
-
-if (defaultChapter.value) {
-  currentChapterId.value = defaultChapter.value.id
-}
+const currentChapterId = ref(resolveInitialChapter())
 
 function selectChapter(chapterId: string) {
   if (!props.unlockedChapterIds.has(chapterId)) return
   currentChapterId.value = chapterId
+  localStorage.setItem('story_chapter', chapterId)
   showChapterPicker.value = false
 }
 
@@ -256,7 +244,7 @@ const tree = computed(() => buildTreeForChapter(currentChapterId.value))
           <div class="picker-panel">
             <div class="picker-grid">
               <div
-                v-for="ch in chaptersByProgress()"
+                v-for="ch in chapters"
                 :key="ch.id"
                 class="picker-card"
                 :class="{ locked: !unlockedChapterIds.has(ch.id), active: ch.id === currentChapterId }"