fix #5897 - allow SQLite to drop columns, remove deprecated columns, and handle upgrade logic

Oqtane.Shared/Models/File.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel.DataAnnotations.Schema;
+using System.Text.Json.Serialization;
 using Oqtane.Shared;
 
 namespace Oqtane.Models
@@ -55,13 +56,6 @@ namespace Oqtane.Models
         /// </summary>
         public string Description { get; set; }
 
-        /// <summary>
-        /// Deprecated
-        /// Note that this property still exists in the database because columns cannot be dropped in SQLite
-        /// Therefore the property must be retained/mapped even though the framework no longer uses it
-        /// </summary>
-        public bool? IsDeleted { get; set; }
-
         /// <summary>
         /// Object reference to the <see cref="Folder"/> object.
         /// Use this if you need to determine what <see cref="Site"/> the file belongs to. 
@@ -74,5 +68,16 @@ namespace Oqtane.Models
         /// </summary>
         [NotMapped]
         public string Url { get; set; }
+
+        #region Deprecated Properties
+
+        [Obsolete("The IsDeleted property is deprecated. Soft delete of files is not supported.", false)]
+        [NotMapped]
+        [JsonIgnore] // exclude from API payload
+        public bool? IsDeleted { get; set; }
+
+        #endregion
+
+
     }
 }