fix(local-music): 扫描自动清理已删除文件，修复双滚动条

- scanFolders() 扫描时收集磁盘文件路径，完成后自动移除 IndexedDB 中已删除的条目
- 移除外层 n-scrollbar，改用 flex 布局，n-virtual-list 作为唯一滚动容器

src/renderer/store/modules/localMusic.ts

@@ -125,6 +125,9 @@ export const useLocalMusicStore = defineStore(
           cachedMap.set(entry.filePath, entry);
         }
 
+        // 磁盘上实际存在的文件路径集合（扫描时收集）
+        const diskFilePaths = new Set<string>();
+
         // 遍历每个文件夹进行扫描
         for (const folderPath of folderPaths.value) {
           try {
@@ -141,6 +144,11 @@ export const useLocalMusicStore = defineStore(
             const { files } = result;
             scanProgress.value += files.length;
 
+            // 记录磁盘上存在的文件
+            for (const file of files) {
+              diskFilePaths.add(file.path);
+            }
+
             // 2. 增量扫描：基于修改时间筛选需重新解析的文件
             const parseTargets: string[] = [];
             for (const file of files) {
@@ -168,6 +176,13 @@ export const useLocalMusicStore = defineStore(
           }
         }
 
+        // 4. 清理已删除文件：从 IndexedDB 移除磁盘上不存在的条目
+        for (const [filePath, entry] of cachedMap) {
+          if (!diskFilePaths.has(filePath)) {
+            await localDB.deleteData(LOCAL_MUSIC_STORE, entry.id);
+          }
+        }
+
         // 5. 从 IndexedDB 重新加载完整列表
         musicList.value = await localDB.getAllData(LOCAL_MUSIC_STORE);
       } catch (error) {

src/renderer/views/local-music/index.vue

@@ -1,9 +1,10 @@
 <template>
-  <div class="local-music-page h-full w-full bg-white dark:bg-black transition-colors duration-500">
-    <n-scrollbar class="h-full">
-      <div class="local-music-content pb-32">
+  <div
+    class="local-music-page h-full w-full overflow-hidden bg-white dark:bg-black transition-colors duration-500"
+  >
+    <div class="local-music-content h-full flex flex-col">
       <!-- Hero Section -->
-        <section class="hero-section relative overflow-hidden rounded-tl-2xl">
+      <section class="hero-section relative overflow-hidden rounded-tl-2xl shrink-0">
         <!-- 背景模糊效果 -->
         <div class="hero-bg absolute inset-0 -top-20">
           <div
@@ -48,7 +49,7 @@
 
       <!-- Action Bar (Sticky) -->
       <section
-          class="action-bar sticky top-0 z-20 page-padding-x py-3 md:py-4 bg-white/80 dark:bg-black/80 backdrop-blur-xl border-b border-neutral-100 dark:border-neutral-800/50"
+        class="action-bar z-20 shrink-0 page-padding-x py-3 md:py-4 bg-white/80 dark:bg-black/80 backdrop-blur-xl border-b border-neutral-100 dark:border-neutral-800/50"
       >
         <div class="flex items-center justify-between gap-4">
           <!-- 左侧：搜索框 -->
@@ -111,7 +112,7 @@
       </section>
 
       <!-- 扫描进度提示 -->
-        <section v-if="localMusicStore.scanning" class="page-padding-x mt-6">
+      <section v-if="localMusicStore.scanning" class="page-padding-x mt-6 shrink-0">
         <div
           class="flex items-center gap-4 p-4 rounded-2xl bg-primary/5 dark:bg-primary/10 border border-primary/20"
         >
@@ -128,7 +129,7 @@
       </section>
 
       <!-- 歌曲列表 -->
-        <section class="list-section page-padding-x mt-6">
+      <section class="list-section page-padding-x mt-6 flex-1 min-h-0">
         <!-- 空状态 -->
         <div
           v-if="!localMusicStore.scanning && filteredList.length === 0"
@@ -146,10 +147,9 @@
         </div>
 
         <!-- 虚拟列表 -->
-          <div v-else-if="filteredList.length > 0" class="song-list-container">
+        <div v-else-if="filteredList.length > 0" class="song-list-container h-full">
           <n-virtual-list
-              class="song-virtual-list"
-              style="max-height: calc(100vh - 280px)"
+            class="song-virtual-list h-full"
             :items="filteredSongResults"
             :item-size="70"
             item-resizable
@@ -166,7 +166,6 @@
         </div>
       </section>
     </div>
-    </n-scrollbar>
 
     <!-- 文件夹管理抽屉 -->
     <n-drawer v-model:show="showFolderManager" :width="400" placement="right">