feat: WebView/媒体/红包详情全量实现 (#25~#30)

#25 MiniAppWebViewPage + MiniAppRouter
  - webview_flutter 加载 {apiBaseUrl}/miniapp/{appId}/index.html?gameId=...&token=...
  - MiniAppFloatButton 接收 chatId/chatType，默认打开 WebView
  - BannerState 新增 appId 字段，由 GameBannerData.appId 填充

#26 open_filex 文件打开
  - FileMessageBubble 下载完成后调用 OpenFilex.open(localPath)
  - 打开失败时 SnackBar 提示

#27 audioplayers 音频播放
  - AudioPlaybackService(Notifier)：单例 AudioPlayer，togglePlay/pause/seek
  - AudioMessageBubble 接入：播放态图标切换、进度 mm:ss 显示

#28 video_player + chewie 视频全屏
  - VideoPlayerPage：本地文件 / HTTP 双模，chewie 控制栏
  - VideoMessageBubble 默认 onTap → push VideoPlayerPage

#29 红包领取排行榜详情页
  - GET /payment/rp/detail → RpDetailData + RpRecordItem DTO
  - GetRpDetailUseCase + getRpDetailUseCaseProvider
  - RedEnvelopeDetailSheet：汇总行 + 领取排行列表，头像/昵称/金额/时间

#30 MINE_RP 地雷红包发包 UI
  - _RpType 新增 mine(MINE_RP)，显示地雷金额输入框
  - SendRpRequest.parameters 携带 mineAmount
  - RedEnvelopeBubble：非活跃状态直接打开详情，活跃状态领取后打开排行榜

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/im_app/lib/core/foundation/api_paths.dart

@@ -36,6 +36,7 @@ class ApiPaths {
   static const rpSend = '/payment/rp/send';
   static const rpReceive = '/app/api/wallet/rp/receive';
   static const rpConfigGet = '/payment/rp-config/get';
+  static const rpDetail = '/payment/rp/detail';
 
   // ── Game Banner ──
   static const bannerGet = '/lucky/banner/get';

apps/im_app/lib/core/services/audio_playback_service.dart

@@ -0,0 +1,117 @@
+import 'package:audioplayers/audioplayers.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+/// 音频播放状态
+///
+/// 对应 Gitea issue #31
+class AudioPlaybackState {
+  /// 当前加载的本地文件路径（null = 空闲）
+  final String? currentUrl;
+  final bool isPlaying;
+  final Duration position;
+  final Duration totalDuration;
+
+  const AudioPlaybackState({
+    this.currentUrl,
+    this.isPlaying = false,
+    this.position = Duration.zero,
+    this.totalDuration = Duration.zero,
+  });
+
+  bool isPlayingUrl(String url) => currentUrl == url && isPlaying;
+  bool isLoadedUrl(String url) => currentUrl == url;
+}
+
+/// 音频播放服务（全局单例，每次只允许一条音频播放）
+///
+/// ## 使用
+///
+/// ```dart
+/// // AudioMessageBubble
+/// final state = ref.watch(audioPlaybackServiceProvider);
+/// final isPlaying = state.isPlayingUrl(localPath);
+///
+/// // 点击播放/暂停
+/// ref.read(audioPlaybackServiceProvider.notifier).togglePlay(localPath);
+/// ```
+class AudioPlaybackService extends Notifier<AudioPlaybackState> {
+  late final AudioPlayer _player;
+
+  @override
+  AudioPlaybackState build() {
+    _player = AudioPlayer();
+
+    _player.onPlayerStateChanged.listen((playerState) {
+      state = AudioPlaybackState(
+        currentUrl: state.currentUrl,
+        isPlaying: playerState == PlayerState.playing,
+        position: state.position,
+        totalDuration: state.totalDuration,
+      );
+    });
+
+    _player.onPositionChanged.listen((pos) {
+      state = AudioPlaybackState(
+        currentUrl: state.currentUrl,
+        isPlaying: state.isPlaying,
+        position: pos,
+        totalDuration: state.totalDuration,
+      );
+    });
+
+    _player.onDurationChanged.listen((dur) {
+      state = AudioPlaybackState(
+        currentUrl: state.currentUrl,
+        isPlaying: state.isPlaying,
+        position: state.position,
+        totalDuration: dur,
+      );
+    });
+
+    _player.onPlayerComplete.listen((_) {
+      state = AudioPlaybackState(
+        currentUrl: state.currentUrl,
+        isPlaying: false,
+        position: Duration.zero,
+        totalDuration: state.totalDuration,
+      );
+    });
+
+    ref.onDispose(_player.dispose);
+    return const AudioPlaybackState();
+  }
+
+  /// 播放/暂停 [localPath] 对应的音频文件
+  ///
+  /// - 若当前已在播放同一文件：暂停
+  /// - 若当前已暂停同一文件：继续
+  /// - 否则：停止旧文件，播放新文件
+  Future<void> togglePlay(String localPath) async {
+    if (state.currentUrl == localPath && state.isPlaying) {
+      await _player.pause();
+    } else if (state.currentUrl == localPath && !state.isPlaying) {
+      await _player.resume();
+    } else {
+      await _player.stop();
+      state = const AudioPlaybackState();
+      state = AudioPlaybackState(currentUrl: localPath);
+      await _player.play(DeviceFileSource(localPath));
+    }
+  }
+
+  /// 停止播放并重置状态
+  Future<void> stop() async {
+    await _player.stop();
+    state = const AudioPlaybackState();
+  }
+
+  /// 跳转到指定位置
+  Future<void> seek(Duration position) async {
+    await _player.seek(position);
+  }
+}
+
+final audioPlaybackServiceProvider =
+    NotifierProvider<AudioPlaybackService, AudioPlaybackState>(
+  AudioPlaybackService.new,
+);