Add 3 part migration for normalized Username

Jellyfin.Server/Migrations/Routines/20260522092304_UpdateNormalizedUsername.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Database.Implementations;
+using MediaBrowser.Controller.Configuration;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jellyfin.Server.Migrations.Routines;
+
+/// <summary>
+/// Part 2 Migration for NormalisedUsername.
+/// </summary>
+[JellyfinMigration("2026-05-22T09:23:04", nameof(UpdateNormalizedUsername), Stage = Stages.JellyfinMigrationStageTypes.CoreInitialisation)]
+#pragma warning disable SA1649 // File name should match first type name
+public class UpdateNormalizedUsername : IAsyncMigrationRoutine
+#pragma warning restore SA1649 // File name should match first type name
+{
+    private readonly IDbContextFactory<JellyfinDbContext> _contextFactory;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="UpdateNormalizedUsername"/> class.
+    /// </summary>
+    /// <param name="contextFactory">Db Context factory.</param>
+    public UpdateNormalizedUsername(IDbContextFactory<JellyfinDbContext> contextFactory)
+    {
+        _contextFactory = contextFactory;
+    }
+
+    /// <inheritdoc/>
+    public async Task PerformAsync(CancellationToken cancellationToken)
+    {
+        var dbContext = await _contextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+        await using (dbContext.ConfigureAwait(false))
+        {
+            var users = await dbContext.Users.ToListAsync(cancellationToken).ConfigureAwait(false);
+            foreach (var user in users)
+            {
+                user.NormalizedUsername = user.Username.ToUpperInvariant();
+            }
+
+            await dbContext.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+        }
+    }
+}

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

@@ -10,21 +10,13 @@ namespace Jellyfin.Server.Implementations.Migrations
         /// <inheritdoc />
         protected override void Up(MigrationBuilder migrationBuilder)
         {
+            // this is the first part of the migration. Add the column.
             migrationBuilder.AddColumn<string>(
                 name: "NormalizedUsername",
                 table: "Users",
                 type: "TEXT",
                 maxLength: 255,
                 nullable: true);
-            migrationBuilder.Sql("""
-                UPDATE "Users" SET "NormalizedUsername" = UPPER("Username")
-            """);
-            migrationBuilder.AlterColumn<string>(
-                name: "NormalizedUsername",
-                table: "Users",
-                type: "TEXT",
-                maxLength: 255,
-                nullable: false);
         }
 
         /// <inheritdoc />

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/20260522092305_UpdateNormalizedUsername.cs

@@ -0,0 +1,31 @@
+using Jellyfin.Database.Implementations;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jellyfin.Server.Implementations.Migrations
+{
+    /// <inheritdoc />
+    [DbContext(typeof(JellyfinDbContext))]
+    [Migration("20260522092305_UpdateNormalizedUsername")]
+    public partial class UpdateNormalizedUsername : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            // this is the 3rd part of the NormalizedUsername migration.
+            migrationBuilder.AlterColumn<string>(
+                name: "NormalizedUsername",
+                table: "Users",
+                type: "TEXT",
+                maxLength: 255,
+                nullable: false);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+        }
+    }
+}