chore: Assets 디렉토리 구조 정리 및 네이밍 컨벤션 적용

- Assets/_Game/ 하위로 게임 에셋 통합
- External/ 패키지 벤더별 분류 (Synty, Animations, UI)
- 에셋 네이밍 컨벤션 확립 및 적용
  (Data_Skill_, Data_SkillEffect_, Prefab_, Anim_, Model_, BT_ 등)
- pre-commit hook으로 네이밍 컨벤션 자동 검사 추가
- RESTRUCTURE_CHECKLIST.md 작성

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Assets/External/Models/SidekickCharacters/_Demos/Scripts/ExpressionSwitcher.cs

@@ -0,0 +1,167 @@
+using UnityEngine;
+using UnityEngine.UI;
+using System.Collections.Generic;
+
+public class ExpressionSwitcher : MonoBehaviour
+{
+    private Animator _animator;
+
+    // Define a list of expression names (will be dynamically populated)
+    private List<string> _expressionNames = new List<string>();
+
+    private int _currentIndex = 0;
+
+    // Reference to the UI text to display the current emotion
+    [SerializeField] private Text _emotionText;
+
+    // Reference to the button to cycle expressions
+    [SerializeField] private Button _cycleButton;
+
+    // Reference to the UI slider to adjust transition time
+    [SerializeField] private Slider _transitionTimeSlider;
+
+    private float _transitionTime = 0.2f; // Default transition time
+
+    void Start()
+    {
+        _animator = GetComponent<Animator>();
+
+        // Ensure the Animator is assigned
+        if (_animator == null)
+        {
+            Debug.LogWarning("[ExpressionSwitcher] No Animator component found on the GameObject.");
+            return;
+        }
+
+        // Populate the expression names from the Animator states in the specified layer
+        PopulateExpressionNames();
+
+        // Debug: Check what was found
+        Debug.Log($"[ExpressionSwitcher] Found {_expressionNames.Count} expressions:");
+        foreach (var expr in _expressionNames)
+            Debug.Log($"  - {expr}");
+
+        // Debug: Check the layer
+        int layerIndex = _animator.GetLayerIndex("Emotion_Additive");
+        Debug.Log($"[ExpressionSwitcher] Layer 'Emotion_Additive' index: {layerIndex}");
+
+        // Wire up the button
+        if (_cycleButton != null)
+        {
+            _cycleButton.onClick.AddListener(CycleExpressions);
+            Debug.Log("[ExpressionSwitcher] Button wired up successfully");
+        }
+        else
+        {
+            Debug.LogWarning("[ExpressionSwitcher] No button assigned in Inspector!");
+        }
+
+        // Ensure the slider is assigned
+        if (_transitionTimeSlider != null)
+        {
+            _transitionTimeSlider.minValue = 0.0f;
+            _transitionTimeSlider.maxValue = 1.0f;
+            _transitionTimeSlider.value = _transitionTime;
+
+            // Read the initial value from the slider to set the transition time
+            UpdateTransitionTime(_transitionTimeSlider.value);
+
+            // Add a listener to handle value changes
+            _transitionTimeSlider.onValueChanged.AddListener(UpdateTransitionTime);
+        }
+    }
+
+    private void PopulateExpressionNames()
+    {
+        RuntimeAnimatorController ac = _animator.runtimeAnimatorController;
+
+        if (ac != null)
+        {
+            Debug.Log($"[ExpressionSwitcher] Scanning {ac.animationClips.Length} animation clips...");
+
+            foreach (AnimationClip clip in ac.animationClips)
+            {
+                if (clip.name.Contains("A_FacePose") && !_expressionNames.Contains(clip.name) && !clip.name.Contains("Neutral"))
+                {
+                    _expressionNames.Add(clip.name);
+                }
+            }
+        }
+        else
+        {
+            Debug.LogError("[ExpressionSwitcher] AnimatorController is not found.");
+        }
+    }
+
+    public void CycleExpressions()
+    {
+        Debug.Log("[ExpressionSwitcher] CycleExpressions() called");
+
+        if (_animator == null)
+        {
+            Debug.LogError("[ExpressionSwitcher] Animator is null!");
+            return;
+        }
+
+        if (_expressionNames.Count == 0)
+        {
+            Debug.LogError("[ExpressionSwitcher] No expressions found in list!");
+            return;
+        }
+
+        string layerName = "Emotion_Additive";
+        int layerIndex = _animator.GetLayerIndex(layerName);
+
+        if (layerIndex == -1)
+        {
+            Debug.LogError($"[ExpressionSwitcher] Layer '{layerName}' not found!");
+            return;
+        }
+
+        string expressionName = _expressionNames[_currentIndex];
+        int stateHash = Animator.StringToHash(expressionName);
+        bool hasState = _animator.HasState(layerIndex, stateHash);
+
+        Debug.Log($"[ExpressionSwitcher] Trying expression: '{expressionName}' (index {_currentIndex})");
+        Debug.Log($"[ExpressionSwitcher] State hash: {stateHash}, HasState: {hasState}");
+
+        if (hasState)
+        {
+            _animator.CrossFadeInFixedTime(expressionName, _transitionTime, layerIndex);
+            Debug.Log($"[ExpressionSwitcher] Playing '{expressionName}'");
+        }
+        else
+        {
+            Debug.LogWarning($"[ExpressionSwitcher] State '{expressionName}' not found, trying 'Neutral'");
+            _animator.CrossFadeInFixedTime("Neutral", _transitionTime, layerIndex);
+        }
+
+        // Update the emotion text after playing the animation
+        UpdateEmotionText();
+
+        // Move to the next expression in the list
+        _currentIndex = (_currentIndex + 1) % _expressionNames.Count;
+    }
+
+    private void UpdateEmotionText()
+    {
+        if (_emotionText != null && _expressionNames.Count > 0)
+        {
+            string expressionName = _expressionNames[_currentIndex];
+            int underscoreIndex = expressionName.LastIndexOf('_');
+            if (underscoreIndex != -1 && underscoreIndex < expressionName.Length - 1)
+            {
+                _emotionText.text = expressionName.Substring(underscoreIndex + 1);
+            }
+            else
+            {
+                _emotionText.text = expressionName; // Fallback if no underscore found
+            }
+        }
+    }
+
+    private void UpdateTransitionTime(float value)
+    {
+        _transitionTime = value;
+    }
+}