feat(player): 倍速改为底部弹窗选择

lib/pages/player/player_view.dart

@@ -72,6 +72,7 @@ class PlayerPage extends StatefulWidget {
 class _PlayerPageState extends State<PlayerPage> with WidgetsBindingObserver {
   late final PlayerLogic logic;
   bool _chromeVisible = true;
+  double _playbackSpeed = 1.0;
 
   @override
   void initState() {
@@ -384,6 +385,8 @@ class _PlayerPageState extends State<PlayerPage> with WidgetsBindingObserver {
                 ? () => unawaited(logic.playNextEpisode())
                 : null,
             playing: logic.session.userWantsPlay,
+            playbackSpeed: _playbackSpeed,
+            onSpeedTap: () => unawaited(_openSpeedSheet(context)),
             controlsVisible: _chromeVisible,
             onClear: () => setState(() => _chromeVisible = false),
             onExitClear: () => setState(() => _chromeVisible = true),
@@ -469,6 +472,18 @@ class _PlayerPageState extends State<PlayerPage> with WidgetsBindingObserver {
       ],
     );
   }
+
+  Future<void> _openSpeedSheet(BuildContext context) async {
+    final selected = await showModalBottomSheet<double>(
+      context: context,
+      backgroundColor: AppColors.card,
+      showDragHandle: true,
+      builder: (_) => _PlaybackSpeedSheet(selected: _playbackSpeed),
+    );
+    if (selected == null || !mounted) return;
+    setState(() => _playbackSpeed = selected);
+    await logic.setPlaybackSpeed(selected);
+  }
 }
 
 /// 不可播放提示：文案由后端返回的 `accessType` 驱动（契约 §1.4），前端不自行推断。
@@ -602,6 +617,8 @@ class _PlaybackOverlay extends StatefulWidget {
     required this.liked,
     required this.saved,
     required this.playing,
+    required this.playbackSpeed,
+    required this.onSpeedTap,
     required this.controlsVisible,
     required this.onTogglePlay,
     required this.onClear,
@@ -626,6 +643,8 @@ class _PlaybackOverlay extends StatefulWidget {
   final bool liked;
   final bool saved;
   final bool playing;
+  final double playbackSpeed;
+  final VoidCallback onSpeedTap;
   final bool controlsVisible;
   final VoidCallback onTogglePlay;
   final VoidCallback onClear;
@@ -667,14 +686,28 @@ class _PlaybackOverlayState extends State<_PlaybackOverlay> {
                 Expanded(
                   child: Stack(
                     children: [
-                      const Positioned(
+                      Positioned(
                         right: 10,
                         bottom: 14,
-                        child: Text(
-                          '1.0x',
-                          style: TextStyle(
-                            color: Color(0xFFDDDDDD),
-                            fontSize: 9,
+                        child: Material(
+                          color: Colors.transparent,
+                          child: InkWell(
+                            key: const Key('player-speed'),
+                            onTap: widget.onSpeedTap,
+                            borderRadius: BorderRadius.circular(6),
+                            child: Padding(
+                              padding: const EdgeInsets.symmetric(
+                                horizontal: 4,
+                                vertical: 2,
+                              ),
+                              child: Text(
+                                _speedLabel(widget.playbackSpeed),
+                                style: const TextStyle(
+                                  color: Color(0xFFDDDDDD),
+                                  fontSize: 9,
+                                ),
+                              ),
+                            ),
                           ),
                         ),
                       ),
@@ -920,6 +953,69 @@ class _PlaybackOverlayState extends State<_PlaybackOverlay> {
   }
 }
 
+const List<double> _speedOptions = [0.5, 0.75, 1.0, 1.25, 1.5, 2.0];
+
+String _speedLabel(double value) => '${value.toString()}x';
+
+class _PlaybackSpeedSheet extends StatelessWidget {
+  const _PlaybackSpeedSheet({required this.selected});
+
+  final double selected;
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    return SafeArea(
+      child: Column(
+        key: const Key('player-speed-sheet'),
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Padding(
+            padding: const EdgeInsets.fromLTRB(20, 2, 20, 8),
+            child: Align(
+              alignment: Alignment.centerLeft,
+              child: Text(
+                l10n.playbackSpeed,
+                style: const TextStyle(
+                  color: AppColors.onSurface,
+                  fontSize: 14,
+                  fontWeight: FontWeight.w700,
+                ),
+              ),
+            ),
+          ),
+          for (final value in _speedOptions)
+            ListTile(
+              key: Key('player-speed-${value.toString()}'),
+              dense: true,
+              tileColor: value == selected
+                  ? AppColors.blue.withValues(alpha: 0.12)
+                  : null,
+              title: Text(
+                _speedLabel(value),
+                style: TextStyle(
+                  color: value == selected ? AppColors.blue : AppColors.cream,
+                  fontSize: 13,
+                  fontWeight: value == selected
+                      ? FontWeight.w700
+                      : FontWeight.w500,
+                ),
+              ),
+              trailing: value == selected
+                  ? const Icon(
+                      Icons.check_rounded,
+                      color: AppColors.blue,
+                      size: 18,
+                    )
+                  : null,
+              onTap: () => Navigator.pop(context, value),
+            ),
+        ],
+      ),
+    );
+  }
+}
+
 class _TopAction extends StatelessWidget {
   const _TopAction({
     super.key,