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/_Game/Scripts/UI/StatBar.cs

@@ -0,0 +1,117 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace Colosseum.UI
+{
+    /// <summary>
+    /// 체력/마나 바 UI 컴포넌트
+    /// Slider 또는 Image.Fill 방식 지원
+    /// </summary>
+    public class StatBar : MonoBehaviour
+    {
+        [Header("References - Slider 방식")]
+        [SerializeField] private Slider slider;
+
+        [Header("References - Fill Image 방식")]
+        [SerializeField] private Image fillImage;
+
+        [Header("References - 텍스트")]
+        [SerializeField] private TMP_Text valueText;
+
+        [Header("Colors")]
+        [SerializeField] private Color fullColor = Color.green;
+        [SerializeField] private Color lowColor = Color.red;
+        [SerializeField] private float lowThreshold = 0.3f;
+        [SerializeField] private bool useColorTransition = true;
+
+        [Header("Animation")]
+        [SerializeField] private bool smoothTransition = true;
+        [SerializeField] private float lerpSpeed = 5f;
+
+        private float currentValue;
+        private float maxValue;
+        private float displayValue;
+
+        /// <summary>
+        /// 바 값 설정
+        /// </summary>
+        public void SetValue(float current, float max)
+        {
+            currentValue = current;
+            maxValue = max;
+
+            if (!smoothTransition)
+            {
+                displayValue = currentValue;
+            }
+            
+            // 항상 즉시 시각적 업데이트 수행
+            UpdateVisuals();
+        }
+
+        private void Update()
+        {
+            if (smoothTransition && !Mathf.Approximately(displayValue, currentValue))
+            {
+                displayValue = Mathf.Lerp(displayValue, currentValue, lerpSpeed * Time.deltaTime);
+
+                if (Mathf.Abs(displayValue - currentValue) < 0.01f)
+                    displayValue = currentValue;
+
+                UpdateVisuals();
+            }
+        }
+
+        private void UpdateVisuals()
+        {
+            if (maxValue <= 0f)
+            {
+                Debug.LogWarning($"[StatBar:{gameObject.name}] UpdateVisuals: maxValue is {maxValue}, skipping");
+                return;
+            }
+
+            float ratio = Mathf.Clamp01(displayValue / maxValue);
+
+            // Slider 방식
+            if (slider != null)
+            {
+                slider.value = ratio;
+
+                // Slider 내부 Fill 이미지 색상 변경
+                if (useColorTransition && slider.fillRect != null)
+                {
+                    var fillImg = slider.fillRect.GetComponent<Image>();
+                    if (fillImg != null)
+                    {
+                        fillImg.color = ratio <= lowThreshold ? lowColor : fullColor;
+                    }
+                }
+            }
+            // Image.Fill 방식
+            else if (fillImage != null)
+            {
+                fillImage.fillAmount = ratio;
+
+                if (useColorTransition)
+                {
+                    fillImage.color = ratio <= lowThreshold ? lowColor : fullColor;
+                }
+            }
+
+            // 텍스트
+            if (valueText != null)
+            {
+                valueText.text = $"{Mathf.CeilToInt(displayValue)} / {Mathf.CeilToInt(maxValue)}";
+            }
+        }
+
+        private void OnValidate()
+        {
+            if (slider == null)
+                slider = GetComponentInChildren<Slider>();
+            if (fillImage == null && slider == null)
+                fillImage = GetComponentInChildren<Image>();
+        }
+    }
+}