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/Player/PlayerCamera.cs

@@ -0,0 +1,162 @@
+using UnityEngine;
+using UnityEngine.InputSystem;
+using UnityEngine.SceneManagement;
+
+namespace Colosseum.Player
+{
+    /// <summary>
+    /// 3인칭 카메라 컨트롤러
+    /// </summary>
+    public class PlayerCamera : MonoBehaviour
+    {
+        [Header("Camera Settings")]
+        [SerializeField] private float distance = 5f;
+        [SerializeField] private float height = 2f;
+        [SerializeField] private float rotationSpeed = 2f;
+        [SerializeField] private float minPitch = -30f;
+        [SerializeField] private float maxPitch = 60f;
+
+        private Transform target;
+        private float yaw;
+        private float pitch;
+        private Camera cameraInstance;
+        private InputSystem_Actions inputActions;
+        private bool isSpectating = false;
+
+        public Transform Target => target;
+        public bool IsSpectating => isSpectating;
+
+        private void OnEnable()
+        {
+            SceneManager.sceneLoaded += OnSceneLoaded;
+        }
+
+        private void OnDisable()
+        {
+            SceneManager.sceneLoaded -= OnSceneLoaded;
+        }
+
+        private void OnSceneLoaded(Scene scene, LoadSceneMode mode)
+        {
+            // 씬 로드 시 카메라 참조 갱신
+            RefreshCamera();
+            SnapToTarget();
+
+            Debug.Log($"[PlayerCamera] Scene loaded, camera refreshed");
+        }
+
+        public void Initialize(Transform playerTransform, InputSystem_Actions actions)
+        {
+            target = playerTransform;
+            inputActions = actions;
+            isSpectating = false;
+
+            // 기존 메인 카메라 사용 또는 새로 생성
+            cameraInstance = Camera.main;
+            if (cameraInstance == null)
+            {
+                var cameraObject = new GameObject("PlayerCamera");
+                cameraInstance = cameraObject.AddComponent<Camera>();
+                cameraObject.tag = "MainCamera";
+            }
+
+            // 초기 각도
+            if (target != null)
+            {
+                yaw = target.eulerAngles.y;
+            }
+            pitch = 20f;
+
+            // 카메라 위치를 즉시 타겟 위치로 초기화
+            SnapToTarget();
+        }
+
+        /// <summary>
+        /// 관전 대상 변경
+        /// </summary>
+        public void SetTarget(Transform newTarget)
+        {
+            if (newTarget == null) return;
+
+            target = newTarget;
+            isSpectating = true;
+
+            // 부드러운 전환을 위해 현재 카메라 위치에서 새 타겟으로
+            yaw = target.eulerAngles.y;
+
+            Debug.Log($"[PlayerCamera] Now spectating: {target.name}");
+        }
+
+        /// <summary>
+        /// 원래 플레이어로 복귀
+        /// </summary>
+        public void ResetToPlayer(Transform playerTransform)
+        {
+            target = playerTransform;
+            isSpectating = false;
+        }
+
+        /// <summary>
+        /// 카메라 위치를 타겟 위치로 즉시 이동 (부드러운 전환 없이)
+        /// </summary>
+        public void SnapToTarget()
+        {
+            if (target == null || cameraInstance == null) return;
+
+            Quaternion rotation = Quaternion.Euler(pitch, yaw, 0f);
+            Vector3 offset = rotation * new Vector3(0f, 0f, -distance);
+            offset.y += height;
+
+            cameraInstance.transform.position = target.position + offset;
+            cameraInstance.transform.LookAt(target.position + Vector3.up * height * 0.5f);
+        }
+
+        /// <summary>
+        /// 카메라 참조 갱신 (씬 전환 후 호출)
+        /// </summary>
+        public void RefreshCamera()
+        {
+            // 씬 전환 시 항상 새 카메라 참조 획득
+            cameraInstance = Camera.main;
+        }
+
+        private void LateUpdate()
+        {
+            // 카메라 참조가 없으면 갱신 시도
+            if (cameraInstance == null)
+            {
+                RefreshCamera();
+            }
+
+            if (target == null || cameraInstance == null) return;
+
+            HandleRotation();
+            UpdateCameraPosition();
+        }
+
+        private void HandleRotation()
+        {
+            if (inputActions == null) return;
+
+            // Input Actions에서 Look 입력 받기
+            Vector2 lookInput = inputActions.Player.Look.ReadValue<Vector2>();
+            float mouseX = lookInput.x * rotationSpeed * 0.1f;
+            float mouseY = lookInput.y * rotationSpeed * 0.1f;
+
+            yaw += mouseX;
+            pitch -= mouseY;
+            pitch = Mathf.Clamp(pitch, minPitch, maxPitch);
+        }
+
+        private void UpdateCameraPosition()
+        {
+            // 구면 좌표로 카메라 위치 계산
+            Quaternion rotation = Quaternion.Euler(pitch, yaw, 0f);
+            Vector3 offset = rotation * new Vector3(0f, 0f, -distance);
+            offset.y += height;
+
+            cameraInstance.transform.position = target.position + offset;
+            cameraInstance.transform.LookAt(target.position + Vector3.up * height * 0.5f);
+        }
+    }
+}