Add unqiue contraint for NormalizedUsername

src/Jellyfin.Database/Jellyfin.Database.Implementations/ModelConfiguration/UserConfiguration.cs

@@ -50,6 +50,10 @@ namespace Jellyfin.Database.Implementations.ModelConfiguration
             builder
                 .HasIndex(entity => entity.Username)
                 .IsUnique();
+
+            builder
+                .HasIndex(entity => entity.NormalizedUsername)
+                .IsUnique();
         }
     }
 }

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/20260522092303_AddNormalizedUsername.Designer.cs

@@ -1356,6 +1356,9 @@ namespace Jellyfin.Server.Implementations.Migrations
                     b.HasIndex("Username")
                         .IsUnique();
 
+                    b.HasIndex("NormalizedUsername")
+                        .IsUnique();
+
                     b.ToTable("Users");
 
                     b.HasAnnotation("Sqlite:UseSqlReturningClause", false);

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/20260522092303_AddNormalizedUsername.cs

@@ -18,6 +18,12 @@ namespace Jellyfin.Server.Implementations.Migrations
                 maxLength: 255,
                 nullable: false,
                 defaultValue: string.Empty);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Users_NormalizedUsername",
+                table: "Users",
+                column: "NormalizedUsername",
+                unique: true);
         }
 
         /// <inheritdoc />
@@ -26,6 +32,10 @@ namespace Jellyfin.Server.Implementations.Migrations
             migrationBuilder.DropColumn(
                 name: "NormalizedUsername",
                 table: "Users");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Users_NormalizedUsername",
+                table: "Users");
         }
     }
 }

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/JellyfinDbModelSnapshot.cs

@@ -1350,6 +1350,9 @@ namespace Jellyfin.Server.Implementations.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("NormalizedUsername")
+                        .IsUnique();
+
                     b.HasIndex("Username")
                         .IsUnique();