feat(ui): 主页收藏/歌单改为跟手 PageView

之前是"横向手势 + 淡入切换"，与播放页的跟手滑动不一致。
- 列表区改为 SliverFillRemaining + PageView，直接跟手左右滑
- 媒体库/按钮保持固定，外层 CustomScrollView 不再滚动
- 收藏/歌单各自是独立 ListView，可正常纵向滚动
- 去掉原来的 GestureDetector 和淡入动画
- 标题行指示器继续跟随当前页

真机验证：左右滑动切换正常，指示器跟随。

lib/pages/home_page.dart

@@ -162,6 +162,7 @@ class _HomePageState extends BaseState<HomePage> {
 
   /// 0 = 我的收藏，1 = 歌单列表（左右滑动切换）
   int _homeTab = 0;
+  final PageController _homePageController = PageController();
   List<PlaylistSummary> _playlistSummaries = [];
 
   // ========== 滚动控制 ==========
@@ -208,6 +209,7 @@ class _HomePageState extends BaseState<HomePage> {
 
   @override
   void dispose() {
+    _homePageController.dispose();
     _scrollController.dispose();
     super.dispose();
   }
@@ -392,200 +394,165 @@ class _HomePageState extends BaseState<HomePage> {
     );
   }
 
-  Widget _buildHomeSliver() {
+  Widget _buildFavoritesTab() {
     if (_isLoading) {
-      return const SliverFillRemaining(
-        child: Center(
-          child: CircularProgressIndicator(color: Color(0xFFB8D4D0)),
-        ),
+      return const Center(
+        child: CircularProgressIndicator(color: Color(0xFFB8D4D0)),
       );
     }
-    return _homeTab == 0 ? _buildFavoritesSliver() : _buildPlaylistsSliver();
-  }
-
-  Widget _buildFavoritesSliver() {
     if (_favorites.isEmpty) {
-      return SliverFillRemaining(
-        child: AnimatedOpacity(
-          opacity: 1.0 - _listReveal * 0.3,
-          duration: const Duration(milliseconds: 100),
-          child: Center(
-            child: Column(
-              mainAxisAlignment: MainAxisAlignment.center,
-              children: [
-                Icon(Icons.favorite_border, size: 48, color: Colors.grey[600]),
-                const SizedBox(height: 16),
-                Text(
-                  '还没有收藏歌曲\n在音乐库中点击 ♡ 添加',
-                  textAlign: TextAlign.center,
-                  style: TextStyle(
-                    fontSize: 16,
-                    color: Colors.grey[500],
-                    height: 1.6,
-                  ),
-                ),
-              ],
+      return Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Icon(Icons.favorite_border, size: 48, color: Colors.grey[600]),
+            const SizedBox(height: 16),
+            Text(
+              '还没有收藏歌曲\n在音乐库中点击 ♡ 添加',
+              textAlign: TextAlign.center,
+              style: TextStyle(
+                fontSize: 16,
+                color: Colors.grey[500],
+                height: 1.6,
+              ),
             ),
-          ),
+          ],
         ),
       );
     }
 
-    return SliverList(
-      delegate: SliverChildBuilderDelegate(
-        (context, index) {
-          final song = _favorites[index];
-          return TweenAnimationBuilder<double>(
-            key: ValueKey('fav-$_homeTab-$index'),
-            tween: Tween(begin: 0.0, end: 1.0),
-            duration: const Duration(milliseconds: 240),
-            curve: Curves.easeOutCubic,
-            builder: (context, t, child) => Opacity(
-              opacity: t,
-              child: Transform.translate(
-                offset: Offset(0, (1 - t) * 10),
-                child: child,
-              ),
+    return ListView.builder(
+      padding: const EdgeInsets.fromLTRB(
+          20, 0, 20, UIConstants.miniPlayerBottomSpace),
+      itemCount: _favorites.length,
+      itemBuilder: (context, index) {
+        final song = _favorites[index];
+        return Padding(
+          padding: const EdgeInsets.symmetric(vertical: 2),
+          child: ListTile(
+            contentPadding: EdgeInsets.zero,
+            visualDensity: VisualDensity.compact,
+            leading: SongArtwork(
+              filePath: song.artworkPath,
+              size: 44,
+              fallbackIcon: Icons.music_note,
             ),
-            child: Padding(
-              padding: const EdgeInsets.symmetric(vertical: 2),
-              child: ListTile(
-                contentPadding: EdgeInsets.zero,
-                visualDensity: VisualDensity.compact,
-                leading: SongArtwork(
-                  filePath: song.artworkPath,
-                  size: 44,
-                  fallbackIcon: Icons.music_note,
-                ),
-                title: Text(
-                  song.displayTitle,
-                  style: const TextStyle(
-                    fontSize: 16,
-                    fontWeight: FontWeight.w400,
-                    color: Colors.white,
-                  ),
-                  maxLines: 1,
-                  overflow: TextOverflow.ellipsis,
-                ),
-                subtitle: Text(
-                  song.displaySubtitle,
-                  style: TextStyle(fontSize: 13, color: Colors.grey[400]),
-                  maxLines: 1,
-                  overflow: TextOverflow.ellipsis,
-                ),
-                trailing: IconButton(
-                  icon: const Icon(
-                    Icons.favorite,
-                    color: Color(0xFFE05C5C),
-                    size: 20,
-                  ),
-                  onPressed: () async {
-                    await SongDatabase().removeFavorite(song.path);
-                    await _loadFavoritesFromDb();
-                    if (mounted) safeSetState(() {});
-                  },
-                ),
-                onTap: () => _playFavorites(index),
+            title: Text(
+              song.displayTitle,
+              style: const TextStyle(
+                fontSize: 16,
+                fontWeight: FontWeight.w400,
+                color: Colors.white,
               ),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
             ),
-          );
-        },
-        childCount: _favorites.length,
-      ),
-    );
-  }
-
-  Widget _buildPlaylistsSliver() {
-    if (_playlistSummaries.isEmpty) {
-      return SliverFillRemaining(
-        child: Center(
-          child: Column(
-            mainAxisAlignment: MainAxisAlignment.center,
-            children: [
-              Icon(Icons.queue_music, size: 48, color: Colors.grey[600]),
-              const SizedBox(height: 16),
-              Text(
-                '还没有歌单\n在文件列表长按歌曲即可加入',
-                textAlign: TextAlign.center,
-                style: TextStyle(
-                  fontSize: 16,
-                  color: Colors.grey[500],
-                  height: 1.6,
-                ),
-              ),
-            ],
-          ),
-        ),
-      );
-    }
-
-    return SliverList(
-      delegate: SliverChildBuilderDelegate(
-        (context, index) {
-          final playlist = _playlistSummaries[index];
-          return TweenAnimationBuilder<double>(
-            key: ValueKey('pl-$_homeTab-$index'),
-            tween: Tween(begin: 0.0, end: 1.0),
-            duration: const Duration(milliseconds: 240),
-            curve: Curves.easeOutCubic,
-            builder: (context, t, child) => Opacity(
-              opacity: t,
-              child: Transform.translate(
-                offset: Offset(0, (1 - t) * 10),
-                child: child,
-              ),
+            subtitle: Text(
+              song.displaySubtitle,
+              style: TextStyle(fontSize: 13, color: Colors.grey[400]),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
             ),
-            child: Padding(
-              padding: const EdgeInsets.symmetric(vertical: 2),
-            child: ListTile(
-              contentPadding: EdgeInsets.zero,
-              visualDensity: VisualDensity.compact,
-              leading: Container(
-                width: 44,
-                height: 44,
-                decoration: BoxDecoration(
-                  color: const Color(0xFF1E2A28),
-                  borderRadius: BorderRadius.circular(10),
-                ),
-                child: const Icon(
-                  Icons.queue_music,
-                  color: Color(0xFFB8D4D0),
-                  size: 22,
-                ),
+            trailing: IconButton(
+              icon: const Icon(
+                Icons.favorite,
+                color: Color(0xFFE05C5C),
+                size: 20,
               ),
-              title: Text(
-                playlist.name,
-                style: const TextStyle(
-                  fontSize: 16,
-                  fontWeight: FontWeight.w400,
-                  color: Colors.white,
-                ),
-                maxLines: 1,
-                overflow: TextOverflow.ellipsis,
-              ),
-              subtitle: Text(
-                '${playlist.songCount} 首',
-                style: TextStyle(fontSize: 13, color: Colors.grey[400]),
-              ),
-              onTap: () async {
-                await Navigator.push(
-                  context,
-                  MaterialPageRoute(
-                    builder: (_) => PlaylistDetailPage(
-                      playlistId: playlist.id,
-                      playlistName: playlist.name,
-                    ),
-                  ),
-                );
-                await _loadPlaylistSummaries();
+              onPressed: () async {
+                await SongDatabase().removeFavorite(song.path);
+                await _loadFavoritesFromDb();
                 if (mounted) safeSetState(() {});
               },
             ),
+            onTap: () => _playFavorites(index),
           ),
         );
-        },
-        childCount: _playlistSummaries.length,
-      ),
+      },
+    );
+  }
+
+  Widget _buildPlaylistsTab() {
+    if (_isLoading) {
+      return const Center(
+        child: CircularProgressIndicator(color: Color(0xFFB8D4D0)),
+      );
+    }
+    if (_playlistSummaries.isEmpty) {
+      return Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Icon(Icons.queue_music, size: 48, color: Colors.grey[600]),
+            const SizedBox(height: 16),
+            Text(
+              '还没有歌单\n在文件列表长按歌曲即可加入',
+              textAlign: TextAlign.center,
+              style: TextStyle(
+                fontSize: 16,
+                color: Colors.grey[500],
+                height: 1.6,
+              ),
+            ),
+          ],
+        ),
+      );
+    }
+
+    return ListView.builder(
+      padding: const EdgeInsets.fromLTRB(
+          20, 0, 20, UIConstants.miniPlayerBottomSpace),
+      itemCount: _playlistSummaries.length,
+      itemBuilder: (context, index) {
+        final playlist = _playlistSummaries[index];
+        return Padding(
+          padding: const EdgeInsets.symmetric(vertical: 2),
+          child: ListTile(
+            contentPadding: EdgeInsets.zero,
+            visualDensity: VisualDensity.compact,
+            leading: Container(
+              width: 44,
+              height: 44,
+              decoration: BoxDecoration(
+                color: const Color(0xFF1E2A28),
+                borderRadius: BorderRadius.circular(10),
+              ),
+              child: const Icon(
+                Icons.queue_music,
+                color: Color(0xFFB8D4D0),
+                size: 22,
+              ),
+            ),
+            title: Text(
+              playlist.name,
+              style: const TextStyle(
+                fontSize: 16,
+                fontWeight: FontWeight.w400,
+                color: Colors.white,
+              ),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+            ),
+            subtitle: Text(
+              '${playlist.songCount} 首',
+              style: TextStyle(fontSize: 13, color: Colors.grey[400]),
+            ),
+            onTap: () async {
+              await Navigator.push(
+                context,
+                MaterialPageRoute(
+                  builder: (_) => PlaylistDetailPage(
+                    playlistId: playlist.id,
+                    playlistName: playlist.name,
+                  ),
+                ),
+              );
+              await _loadPlaylistSummaries();
+              if (mounted) safeSetState(() {});
+            },
+          ),
+        );
+      },
     );
   }
 
@@ -725,23 +692,9 @@ class _HomePageState extends BaseState<HomePage> {
             ),
           ),
           Expanded(
-            child: GestureDetector(
-              onHorizontalDragEnd: (details) {
-                final v = details.primaryVelocity ?? 0;
-                if (v < -200 && _homeTab == 0) {
-                  safeSetState(() => _homeTab = 1);
-                } else if (v > 200 && _homeTab == 1) {
-                  safeSetState(() => _homeTab = 0);
-                }
-              },
-              child: CustomScrollView(
+            child: CustomScrollView(
               controller: _scrollController,
-              physics: _mediaLibraryHeight > 0
-                  ? MagneticScrollPhysics(
-                      snapPoint: _mediaLibraryHeight,
-                      magneticZoneStart: 0.20,
-                    )
-                  : const ClampingScrollPhysics(),
+              physics: const NeverScrollableScrollPhysics(),
               slivers: [
                 SliverToBoxAdapter(
                   child: Opacity(
@@ -961,17 +914,20 @@ class _HomePageState extends BaseState<HomePage> {
                     ),
                   ),
                 ),
-                SliverPadding(
-                  padding: const EdgeInsets.only(
-                    left: 20,
-                    right: 20,
-                    bottom: UIConstants.miniPlayerBottomSpace,
+                SliverFillRemaining(
+                  hasScrollBody: true,
+                  child: PageView(
+                    controller: _homePageController,
+                    onPageChanged: (index) =>
+                        safeSetState(() => _homeTab = index),
+                    children: [
+                      _buildFavoritesTab(),
+                      _buildPlaylistsTab(),
+                    ],
                   ),
-                  sliver: _buildHomeSliver(),
                 ),
               ],
             ),
-            ),
           ),
         ],
       ),