Add owner role and admin management controls

Data/Migrations/20260208175912_AddOwnerRole.cs

@@ -0,0 +1,42 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace GameList.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddOwnerRole : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "IsOwner",
+                table: "Players",
+                type: "INTEGER",
+                nullable: false,
+                defaultValue: false);
+
+            migrationBuilder.Sql(
+                """
+                UPDATE Players
+                SET IsOwner = 1
+                WHERE Id = (
+                    SELECT Id
+                    FROM Players
+                    WHERE IsAdmin = 1
+                    ORDER BY CreatedAt, Id
+                    LIMIT 1
+                );
+                """);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "IsOwner",
+                table: "Players");
+        }
+    }
+}