fix(animation): WASM 모드 안정성 개선

- SchedulerBinding으로 프레임 빌드 중 setState 방지
- persistentCallbacks 단계에서 addPostFrameCallback으로 지연 처리

lib/src/features/front/widgets/hero_vs_boss_animation.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:math';
 
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'package:askiineverdie/data/race_data.dart';
 import 'package:askiineverdie/src/core/animation/front_screen_animation.dart';
@@ -45,7 +46,19 @@ class _HeroVsBossAnimationState extends State<HeroVsBossAnimation> {
     _animationTimer = Timer.periodic(
       const Duration(milliseconds: frontScreenAnimationIntervalMs),
       (_) {
-        if (mounted) {
+        if (!mounted) return;
+        // 프레임 빌드 중이면 다음 프레임까지 대기
+        if (SchedulerBinding.instance.schedulerPhase ==
+            SchedulerPhase.persistentCallbacks) {
+          SchedulerBinding.instance.addPostFrameCallback((_) {
+            if (mounted) {
+              setState(() {
+                _currentFrame =
+                    (_currentFrame + 1) % frontScreenAnimationFrameCount;
+              });
+            }
+          });
+        } else {
           setState(() {
             _currentFrame =
                 (_currentFrame + 1) % frontScreenAnimationFrameCount;
@@ -69,10 +82,23 @@ class _HeroVsBossAnimationState extends State<HeroVsBossAnimation> {
     final allRaces = RaceData.all;
     if (allRaces.isEmpty) return;
 
-    setState(() {
+    // 프레임 빌드 중이면 다음 프레임까지 대기
-      _raceIndex = (_raceIndex + 1) % allRaces.length;
+    if (SchedulerBinding.instance.schedulerPhase ==
-      _currentRaceId = allRaces[_raceIndex].raceId;
+        SchedulerPhase.persistentCallbacks) {
-    });
+      SchedulerBinding.instance.addPostFrameCallback((_) {
+        if (mounted) {
+          setState(() {
+            _raceIndex = (_raceIndex + 1) % allRaces.length;
+            _currentRaceId = allRaces[_raceIndex].raceId;
+          });
+        }
+      });
+    } else {
+      setState(() {
+        _raceIndex = (_raceIndex + 1) % allRaces.length;
+        _currentRaceId = allRaces[_raceIndex].raceId;
+      });
+    }
   }
 
   /// 글리치 효과: 랜덤 문자 대체

lib/src/features/new_character/widgets/race_preview.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 
 import 'package:askiineverdie/src/core/animation/character_frames.dart';
 import 'package:askiineverdie/src/core/animation/race_character_frames.dart';
@@ -48,7 +49,19 @@ class _RacePreviewState extends State<RacePreview> {
 
   void _startAnimation() {
     _timer = Timer.periodic(const Duration(milliseconds: 400), (_) {
-      if (mounted) {
+      if (!mounted) return;
+
+      // 프레임 빌드 중이면 다음 프레임까지 대기 (WASM 모드 안정성)
+      if (SchedulerBinding.instance.schedulerPhase ==
+          SchedulerPhase.persistentCallbacks) {
+        SchedulerBinding.instance.addPostFrameCallback((_) {
+          if (mounted) {
+            setState(() {
+              _currentFrame++;
+            });
+          }
+        });
+      } else {
         setState(() {
           _currentFrame++;
         });