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';