feat(redpacket): 红包与游戏横幅全量实现 (#19~#24)

- #19 fix: SendRedEnvelopeUseCase 动态取 currencyType（workspaceId>0 取
  workspace.currency，修复 iOS 硬编码 PEA → 150001 错误）
- #20: RedEnvelopeBubble typ=8，四态（橙色领取/已领/过期/抢完）+ 领取按钮
- #21: ReceiveRedEnvelopeUseCase POST /app/api/wallet/rp/receive，
  typed JSON body（避免 code=30007），SnackBar 反馈
- #22: SendRedEnvelopeSheet BottomSheet，STANDARD_RP + LUCKY_RP，
  发送成功后构建 typ=8 content JSON 回调给 ChatPage
- #23: BannerViewModel Notifier，Group.topic 双格式解析（JSON object/string），
  FetchBannerUseCase + Timer 倒计时 + applyNewRound WS 接口
- #24: BannerView 游戏横幅条（状态/倒计时/上期结果），
  MiniAppFloatButton 悬浮按钮（hasGame 显示/隐藏，onTap TODO #25）

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

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

@@ -32,6 +32,17 @@ class ApiPaths {
   static const accountStoreGet = '/app/api/account/store/get-store';
   static const accountStoreUpdate = '/app/api/account/store/update-store';
 
+  // ── Red Envelope ──
+  static const rpSend = '/payment/rp/send';
+  static const rpReceive = '/app/api/wallet/rp/receive';
+  static const rpConfigGet = '/payment/rp-config/get';
+
+  // ── Game Banner ──
+  static const bannerGet = '/lucky/banner/get';
+
+  // ── Workspace ──
+  static const workspaceGet = '/workspace/workspace/get';
+
   // ── Upload ──
   static const uploadFile = '/app/api/upload/file';