fix(mobile-next): 按 B-91 收口 Android 通话视觉打回项

呼出/通话中按钮、计时器、底色、60s 未接与进出场动效对齐视觉规范。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

mobile-next/lib/company/rtc/call_session_guard.dart

@@ -1,11 +1,13 @@
 import 'dart:async';
 
+import '../brand/app_tokens.dart';
+
 /// 一对一语音会话防护：占线、超时、重复信令、销毁时释放计时器。
 /// 不自建第二套信令，只约束官方 OpenIMLive 的进出场。
 enum VoiceCallPhase { idle, outgoing, incoming, inCall }
 
 class CallSessionGuard {
-  CallSessionGuard({this.inviteTimeout = const Duration(seconds: 30)});
+  CallSessionGuard({this.inviteTimeout = AppDuration.callInviteTimeout});
 
   final Duration inviteTimeout;