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/UI/InterfaceFantasyWarriorHUD/Samples/Scripts/SampleCountdownLabel.cs

@@ -0,0 +1,90 @@
+// Copyright (c) 2024 Synty Studios Limited. All rights reserved.
+//
+// Use of this software is subject to the terms and conditions of the Synty Studios End User Licence Agreement (EULA)
+// available at: https://syntystore.com/pages/end-user-licence-agreement
+//
+// Sample scripts are included only as examples and are not intended as production-ready.
+
+using System.Collections;
+using TMPro;
+using UnityEngine;
+using UnityEngine.Events;
+
+namespace Synty.Interface.FantasyWarriorHUD.Samples
+{
+    /// <summary>
+    ///     A simple countdown label that counts down from a set time.
+    /// </summary>
+    public class SampleCountdownLabel : MonoBehaviour
+    {
+        [Header("References")]
+        public Animator animator;
+        public TMP_Text text;
+
+        [Header("Parameters")]
+        public bool setAnimatorActive = true;
+        public float initialDelay = 0;
+        public float countdownTime = 30;
+        public float updateInterval = 0.1f;
+        public float timeUpDuration = 2.5f;
+        public UnityEvent onCountdownComplete;
+
+        private float currentTime;
+
+        private void Reset()
+        {
+            text = GetComponentInChildren<TMP_Text>();
+        }
+
+        private IEnumerator Start()
+        {
+            yield return new WaitForSeconds(initialDelay);
+
+            BeginTimer();
+        }
+
+        private void BeginTimer()
+        {
+            currentTime = countdownTime;
+            RefreshUI();
+
+            StartCoroutine(C_TickDown());
+        }
+
+        private IEnumerator C_TickDown()
+        {
+            while (currentTime > 0)
+            {
+                yield return new WaitForSeconds(updateInterval);
+
+                currentTime -= updateInterval;
+                if (currentTime <= 0)
+                {
+                    currentTime = 0;
+                }
+
+                RefreshUI();
+            }
+
+            if (setAnimatorActive)
+                animator?.gameObject.SetActive(true);
+            animator?.SetBool("Active", true);
+            yield return new WaitForSeconds(timeUpDuration);
+
+            animator?.SetBool("Active", false);
+            yield return new WaitForSeconds(1);
+
+            if (setAnimatorActive)
+                animator?.gameObject.SetActive(false);
+
+            onCountdownComplete?.Invoke();
+            BeginTimer();
+        }
+
+        private void RefreshUI()
+        {
+            if (text)
+                text.SetText(currentTime.ToString("F1"));
+        }
+    }
+}