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/SidekickPartMetaData.cs

@@ -0,0 +1,48 @@
+// 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;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Synty.SidekickCharacters.Database.DTO
+{
+    [Table("sk_pmdata")]
+    public class SidekickPartMetaData
+    {
+        [PrimaryKey, Column("id")]
+        public int ID { get; set; }
+        [Column("part_guid")]
+        public string PartGuid { get; set; }
+        [Column("name")]
+        public string Name { get; set; }
+        [Column("value")]
+        public string Value { get; set; }
+        [Column("type")]
+        public string Type { get; set; }
+        [Column("value_type")]
+        public string ValueType { get; set; }
+        [Column("last_updated")]
+        public DateTime LastUpdated { get; set; }
+
+        /// <summary>
+        ///     Gets a list of part guids from the meta data based on the passed in type and value.
+        /// </summary>
+        /// <param name="dbManager">The Database Manager to use.</param>
+        /// <param name="type">The type of metadata to search for.</param>
+        /// <param name="value">The value of the metadata to search for.</param>
+        /// <returns>A list of part guids that match the given criteria.</returns>
+        public static List<string> GetPartGuidsByMetaDataValue(DatabaseManager dbManager, string type, string value)
+        {
+            return dbManager.GetCurrentDbConnection().Table<SidekickPartMetaData>()
+                .Where(meta => meta.Type == type && meta.Value == value)
+                .Select(meta => meta.PartGuid)
+                .ToList();
+        }
+    }
+}