refactor(character): 使用整数坐标优化角色位置同步

- 将CharacterWorldPosition改为使用整数坐标，避免浮点精度问题
- 添加位置余数处理，确保移动平滑性
- 统一角色位置同步逻辑到SyncActorPositionFromWorld方法
- 修改地图移动检测使用整数坐标判断

Game/src/character/CharacterObject.cpp

@@ -133,13 +133,18 @@ void CharacterObject::SetDirection(int direction) {
 
 void CharacterObject::SetCharacterPosition(const Vec2& pos) {
   motor_.SetGroundPosition(pos);
-  SetWorldPosition(motor_.position);
+  SyncActorPositionFromWorld();
 }
 
 void CharacterObject::SetWorldPosition(const CharacterWorldPosition& pos) {
-  motor_.position = pos;
-  SetPosition(pos.ToScreenPosition());
-  SetZOrder(static_cast<int>(pos.y));
+  motor_.SetWorldPosition(pos);
+  SyncActorPositionFromWorld();
+}
+
+void CharacterObject::SyncActorPositionFromWorld() {
+  const CharacterWorldPosition& worldPosition = motor_.position;
+  SetPosition(worldPosition.ToScreenPosition());
+  SetZOrder(worldPosition.y);
 }
 
 void CharacterObject::PushCommand(const CharacterCommand& command) {
@@ -240,7 +245,7 @@ void CharacterObject::OnUpdate(float deltaTime) {
   currentIntent_ = commandBuffer_.BuildIntent();
   stateMachine_.Update(*this, commandBuffer_, currentIntent_, deltaTime);
   motor_.Update(deltaTime);
-  SetWorldPosition(motor_.position);
+  SyncActorPositionFromWorld();
   SetFacing(motor_.facing);
 }