feat(app): 곡 상세 화면 뮤직비디오 앱 내 재생 + YouTube 이동 버튼

- 썸네일+재생 버튼 → OmniVideoPlayer로 교체 (앱 내 직접 재생)
- 하단에 'YouTube에서 보기' 텍스트 버튼 추가

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/lib/views/album/track_detail_view.dart

@@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:lucide_icons/lucide_icons.dart';
+import 'package:omni_video_player/omni_video_player.dart';
 import 'package:url_launcher/url_launcher.dart';
 import '../../core/constants.dart';
 import '../../models/album.dart';
@@ -326,59 +327,33 @@ class _MusicVideoSection extends StatelessWidget {
             ],
           ),
           const SizedBox(height: 12),
-          // 썸네일
-          GestureDetector(
-            onTap: onTap,
-            child: Container(
-              width: double.infinity,
-              decoration: BoxDecoration(
-                borderRadius: BorderRadius.circular(12),
-                boxShadow: [
-                  BoxShadow(
-                    color: Colors.black.withValues(alpha: 0.1),
-                    blurRadius: 8,
-                    offset: const Offset(0, 2),
-                  ),
-                ],
-              ),
-              child: ClipRRect(
-                borderRadius: BorderRadius.circular(12),
-                child: AspectRatio(
-                  aspectRatio: 16 / 9,
-                  child: Stack(
-                    fit: StackFit.expand,
-                    children: [
-                      CachedNetworkImage(
-                        imageUrl: 'https://img.youtube.com/vi/$videoId/maxresdefault.jpg',
-                        fit: BoxFit.cover,
-                        placeholder: (context, url) => Container(color: Colors.black),
-                        errorWidget: (context, url, error) => CachedNetworkImage(
-                          imageUrl: 'https://img.youtube.com/vi/$videoId/hqdefault.jpg',
-                          fit: BoxFit.cover,
-                        ),
-                      ),
-                      // 재생 버튼 오버레이
-                      Container(
-                        color: Colors.black.withValues(alpha: 0.3),
-                        child: Center(
-                          child: Container(
-                            width: 56,
-                            height: 56,
-                            decoration: BoxDecoration(
-                              color: Colors.red,
-                              borderRadius: BorderRadius.circular(28),
-                            ),
-                            child: const Icon(
-                              LucideIcons.play,
-                              color: Colors.white,
-                              size: 28,
-                            ),
-                          ),
-                        ),
-                      ),
-                    ],
+          // 영상 플레이어
+          ClipRRect(
+            borderRadius: BorderRadius.circular(12),
+            child: AspectRatio(
+              aspectRatio: 16 / 9,
+              child: OmniVideoPlayer(
+                configuration: VideoPlayerConfiguration(
+                  videoSourceConfiguration: VideoSourceConfiguration.youtube(
+                    videoUrl: Uri.parse('https://www.youtube.com/watch?v=$videoId'),
+                    preferredQualities: [OmniVideoQuality.high720],
                   ),
                 ),
+                callbacks: const VideoPlayerCallbacks(),
+              ),
+            ),
+          ),
+          const SizedBox(height: 8),
+          // YouTube에서 보기 버튼
+          SizedBox(
+            width: double.infinity,
+            child: TextButton.icon(
+              onPressed: onTap,
+              icon: const Icon(LucideIcons.externalLink, size: 14),
+              label: const Text('YouTube에서 보기', style: TextStyle(fontSize: 13)),
+              style: TextButton.styleFrom(
+                foregroundColor: Colors.red,
+                padding: const EdgeInsets.symmetric(vertical: 8),
               ),
             ),
           ),