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/Scripts/Runtime/Database/DTO/SidekickPartImage.cs

@@ -0,0 +1,124 @@
+// 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
+//
+// For additional details, see the LICENSE.MD file bundled with this software.
+
+using SQLite;
+using System.Collections.Generic;
+
+namespace Synty.SidekickCharacters.Database.DTO
+{
+    [Table("sk_part_image")]
+    public class SidekickPartImage
+    {
+        private SidekickPart _part;
+
+        [PrimaryKey, AutoIncrement, Column("id")]
+        public int ID { get; set; }
+        [Column("ptr_part")]
+        public int PtrPart { get; set; }
+        [Column("img_data")]
+        public byte[] ImageData { get; set; }
+        [Column("img_width")]
+        public int Width { get; set; }
+        [Column("img_height")]
+        public int Height { get; set; }
+
+        [Ignore]
+        public SidekickPart Part
+        {
+            get => _part;
+            set
+            {
+                _part = value;
+                PtrPart = value.ID;
+            }
+        }
+
+        /// <summary>
+        ///     Gets a specific Part Image by its database ID.
+        /// </summary>
+        /// <param name="dbManager">The Database Manager to use.</param>
+        /// <param name="id">The id of the required Part Image.</param>
+        /// <returns>The specific Part Image if it exists; otherwise null.</returns>
+        public static SidekickPartImage GetByID(DatabaseManager dbManager, int id)
+        {
+            SidekickPartImage partImage = dbManager.GetCurrentDbConnection().Find<SidekickPartImage>(id);
+            Decorate(dbManager, partImage);
+            return partImage;
+        }
+
+        /// <summary>
+        ///     Gets a specific Part Image for a specific part.
+        /// </summary>
+        /// <param name="dbManager">The Database Manager to use.</param>
+        /// <param name="part">The Part to get the image for.</param>
+        /// <returns>The specific Part Image for a specific part if it exists; otherwise null.</returns>
+        public static SidekickPartImage GetByPart(DatabaseManager dbManager, SidekickPart part)
+        {
+            SidekickPartImage partImage = dbManager.GetCurrentDbConnection().Table<SidekickPartImage>()
+                .FirstOrDefault(pi => pi.PtrPart == part.ID);
+            Decorate(dbManager, partImage);
+            return partImage;
+        }
+
+        /// <summary>
+        ///     Gets a list of all the Part Images in the database.
+        /// </summary>
+        /// <param name="dbManager">The Database Manager to use.</param>
+        /// <returns>A list of all part images in the database.</returns>
+        public static List<SidekickPartImage> GetAll(DatabaseManager dbManager)
+        {
+            List<SidekickPartImage> partImages = dbManager.GetCurrentDbConnection().Table<SidekickPartImage>().ToList();
+
+            foreach (SidekickPartImage partImage in partImages)
+            {
+                Decorate(dbManager, partImage);
+            }
+
+            return partImages;
+        }
+
+        /// <summary>
+        ///     Ensures that the given preset has its nice DTO class properties set
+        /// </summary>
+        /// <param name="dbManager">The Database Manager to use.</param>
+        /// <param name="partImage">The part image to decorate</param>
+        private static void Decorate(DatabaseManager dbManager, SidekickPartImage partImage)
+        {
+            if (partImage != null)
+            {
+                if (partImage.Part == null && partImage.PtrPart >= 0)
+                {
+                    partImage.Part ??= SidekickPart.GetByID(dbManager, partImage.PtrPart);
+                }
+            }
+        }
+
+        /// <summary>
+        ///     Updates or Inserts this item in the Database.
+        /// </summary>
+        /// <param name="dbManager">The database manager to use.</param>
+        public void Save(DatabaseManager dbManager)
+        {
+            if (ID <= 0)
+            {
+                dbManager.GetCurrentDbConnection().Insert(this);
+                // in theory this could return a different ID, but in practice it's highly unlikely
+                ID = (int) SQLite3.LastInsertRowid(dbManager.GetCurrentDbConnection().Handle);
+            }
+            dbManager.GetCurrentDbConnection().Update(this);
+        }
+
+        /// <summary>
+        ///     Deletes this item from the database
+        /// </summary>
+        /// <param name="dbManager">The database manager to use.</param>
+        public void Delete(DatabaseManager dbManager)
+        {
+            dbManager.GetCurrentDbConnection().Delete<SidekickPartImage>(ID);
+        }
+    }
+}