docs: 为缩略图、最近文件相关新增类型补全中文 XML 文档注释

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

FileShare-EFCore/Models/ManagedThumbnailMap.cs

@@ -4,34 +4,45 @@ using System.ComponentModel.DataAnnotations.Schema;
 
 namespace FileShare_EFCore.Models
 {
+    /// <summary>
+    /// 文件缩略图映射记录，存储视频缩略图的文件路径与内容类型。
+    /// </summary>
     [Comment("文件缩略图映射记录")]
     [Table("managed-thumbnail-map")]
     public class ManagedThumbnailMap
     {
+        /// <summary>主键 ID。</summary>
         [Key]
         [Column("id")]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public int Id { get; set; }
 
+        /// <summary>所属根目录 ID。</summary>
         [Column("library-root-id")]
         public int LibraryRootId { get; set; }
 
+        /// <summary>缩略图相对于缩略图存储根目录的路径。</summary>
         [Column("relative-path")]
         [MaxLength(1024)]
         public string RelativePath { get; set; } = string.Empty;
 
+        /// <summary>缩略图的 MIME 类型。</summary>
         [Column("content-type")]
         [MaxLength(100)]
         public string ContentType { get; set; } = "image/jpeg";
 
+        /// <summary>创建时间 UTC。</summary>
         [Column("created-at")]
         public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
 
+        /// <summary>更新时间 UTC。</summary>
         [Column("updated-at")]
         public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
 
+        /// <summary>所属根目录。</summary>
         public ManagedLibraryRoot? LibraryRoot { get; set; }
 
+        /// <summary>引用了此缩略图的文件记录。</summary>
         public List<ManagedFileRecord> Files { get; set; } = new();
     }
 }