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/features/chat/usecases/get_rp_detail_usecase.dart

@@ -0,0 +1,27 @@
+import 'package:networks_sdk/networks_sdk.dart';
+
+import 'package:im_app/data/remote/red_envelope_request.dart';
+
+/// 获取红包领取详情 UseCase
+///
+/// 对应 Gitea issue #29 / iOS RedEnvelopeDetailSheet 领取排行榜数据源
+///
+/// ## 使用
+///
+/// ```dart
+/// final detail = await ref.read(getRpDetailUseCaseProvider)
+///     .execute(rpId: parsedContent['id']);
+/// ```
+class GetRpDetailUseCase {
+  final NetworksSdkApi _api;
+
+  const GetRpDetailUseCase({required NetworksSdkApi api}) : _api = api;
+
+  Future<RpDetailData> execute({required String rpId}) async {
+    final result = await _api.executeRequest(
+      GetRpDetailRequest(rpId: rpId),
+    );
+    if (result == null) throw Exception('获取红包详情失败');
+    return result;
+  }
+}

apps/im_app/lib/features/chat/usecases/send_red_envelope_usecase.dart

@@ -26,10 +26,11 @@ class SendRedEnvelopeUseCase {
   /// [chatId] 会话 ID
   /// [chatType] 1=私聊 / 2=群聊
   /// [workspaceId] 群 workspaceId（0 表示非工作台群）
-  /// [rpType] "STANDARD_RP" | "LUCKY_RP"（初期支持，后续扩展 MINE_RP / NN_RP）
+  /// [rpType] "STANDARD_RP" | "LUCKY_RP" | "MINE_RP"（NN_RP 由游戏自动触发）
   /// [amount] 总金额字符串，如 "10.00"
   /// [rpNum] 红包数量
   /// [remark] 红包祝福语
+  /// [mineAmount] 地雷金额（仅 MINE_RP 时传入，如 "5.00"）
   Future<String> execute({
     required int chatId,
     required int chatType,
@@ -38,6 +39,7 @@ class SendRedEnvelopeUseCase {
     required String amount,
     required int rpNum,
     required String remark,
+    String? mineAmount,
   }) async {
     // #19 fix: 根据 workspaceId 动态决定 currencyType
     final currencyType = await _resolveCurrencyType(workspaceId);
@@ -53,6 +55,7 @@ class SendRedEnvelopeUseCase {
         rpNum: rpNum,
         remark: remark,
         msgSendTime: DateTime.now().microsecondsSinceEpoch,
+        mineAmount: mineAmount,
       ),
     );