Update to dotnet 9.0, add user roles, MatchStats and OpenApi/Scalar in dev

LaDOSE.Src/LaDOSE.Entity/Roles.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace LaDOSE.Entity
+{
+    /// <summary>
+    /// The role names the API knows about. They must exist as rows in
+    /// <c>applicationrole</c> — see Sql/2026-08-05_roles.sql.
+    /// </summary>
+    public static class Roles
+    {
+        /// <summary>May manage user accounts.</summary>
+        public const string Admin = "Admin";
+
+        /// <summary>May use everything else. The absence of a role means the same thing.</summary>
+        public const string User = "User";
+
+        public static readonly string[] All = { Admin, User };
+
+        /// <summary>Case-insensitive, so 'admin' typed into the SQL seed still counts.</summary>
+        public static bool IsAdmin(this ApplicationUser user)
+        {
+            return user.Names().Any(name => Admin.Equals(name, StringComparison.OrdinalIgnoreCase));
+        }
+
+        /// <summary>
+        /// The user's role names. Empty when the user holds no role, and also when the
+        /// query did not include them — callers that authorize must load them.
+        /// </summary>
+        public static List<string> Names(this ApplicationUser user)
+        {
+            return user?.UserRoles?
+                       .Select(userRole => userRole.Role?.Name)
+                       .Where(name => !string.IsNullOrWhiteSpace(name))
+                       .OrderBy(name => name)
+                       .ToList()
+                   ?? new List<string>();
+        }
+    }
+}