feat(character): 实现角色状态机与输入路由系统

新增角色状态机框架，包含空闲、移动、跳跃、攻击等状态
添加输入路由组件，统一处理键盘和手柄输入
引入动作库管理角色动作定义，支持PVF脚本配置
重构角色对象，整合运动器、状态机和输入处理
修复Actor子节点排序时的迭代安全问题

Game/include/character/CharacterStateMachine.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include "character/CharacterActionLibrary.h"
+
+namespace frostbite2D {
+
+class CharacterObject;
+
+/// 角色主状态机。输入先变成意图，再由状态机决定当前大状态和动作推进。
+class CharacterStateMachine {
+public:
+  void Reset();
+  void Update(CharacterObject& owner,
+              CharacterCommandBuffer& commandBuffer,
+              const CharacterIntent& intent,
+              float deltaTime);
+  void ForceHurt(const CharacterActionDefinition* hurtAction);
+
+  CharacterStateId GetState() const { return currentState_; }
+  const std::string& GetCurrentActionId() const { return currentActionId_; }
+  const CharacterActionDefinition* GetCurrentActionDefinition() const {
+    return currentAction_;
+  }
+
+  bool CanAcceptGroundActions() const;
+  bool CanBeInterrupted() const;
+  bool IsMovementLocked() const;
+  bool CanTurn() const;
+
+private:
+  void ChangeState(CharacterObject& owner, CharacterStateId nextState);
+  void EnterAction(CharacterObject& owner, const CharacterActionDefinition* action);
+  void UpdateGroundState(CharacterObject& owner,
+                         CharacterCommandBuffer& commandBuffer,
+                         const CharacterIntent& intent);
+  void UpdateAirState(CharacterObject& owner,
+                      CharacterCommandBuffer& commandBuffer,
+                      const CharacterIntent& intent);
+  void UpdateActionState(CharacterObject& owner,
+                         CharacterCommandBuffer& commandBuffer,
+                         const CharacterIntent& intent,
+                         float deltaTime);
+  void UpdateHurtState(CharacterObject& owner, float deltaTime);
+  bool TryStartAction(CharacterObject& owner,
+                      CharacterCommandBuffer& commandBuffer,
+                      CharacterCommandType commandType,
+                      const std::string& actionId);
+  void ApplyFrameEvents(CharacterObject& owner, int previousFrame, int currentFrame);
+
+  CharacterStateId currentState_ = CharacterStateId::Idle;
+  std::string currentActionId_;
+  const CharacterActionDefinition* currentAction_ = nullptr;
+  float stateTime_ = 0.0f;
+  float actionFrameProgress_ = 0.0f;
+  int actionFrame_ = 0;
+  float landingTimer_ = 0.0f;
+};
+
+} // namespace frostbite2D