chore: release client-v1.0.70

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YZ4DskSRKsSiheQonFtQvx

client/lib/core/theme/app_theme.dart

@@ -14,6 +14,8 @@ class AppTheme {
 
   static const Color success = Color(0xFF2E8B57);
   static const Color danger = Color(0xFFD14343);
+  /// 警示色（amber）：用于「撤回」等谨慎但非破坏性的操作，文字在白底对比足够。
+  static const Color warning = Color(0xFFB45309);
   static const Color background = Color(0xFFF5F7FA);
   static const Color surface = Color(0xFFFFFFFF);
   static const Color border = Color(0xFFDCE2EB);