Got most of admin panel working. Data issues fixed

OpenArchival.DataAccess/Models/FilePathListing.cs

@@ -1,16 +1,16 @@
 using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
 
 namespace OpenArchival.DataAccess;
 
 public class FilePathListing
 {
     [Key]
+    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
     public int Id { get; set; }
 
     public ArtifactEntry? ParentArtifactEntry { get; set; }
 
-    public int? ParentArtifactEntryId { get; set; }
-
     public required string OriginalName { get; set; }
 
     public required string Path { get; set; }