Decouple UserType, add Role entity and management

Removed all UserType logic and references, replacing them with a new Role model and management system. Introduced RoleManager service, repository, and API endpoint for role CRUD operations. Updated user flows and JWT claims to use RoleCode. Removed admin-only user CRUD endpoints. Updated DI, documentation, and error handling for consistency. Appsettings and DTOs now reflect the new role-based approach.

Services/FunctionHandler/RoleManager.cs

@@ -0,0 +1,72 @@
+using AuthHex.Models.IOs;
+using AuthHex.Services.RoleManager;
+
+namespace AuthHex.Services.FunctionHandler
+{
+    public class RoleManager
+    {
+        public readonly Dictionary<string, Func<object, HttpContext, Task<object>>> _functionHandler;
+
+        public RoleManager(RoleManagerService roleManagerService)
+        {
+            _functionHandler = new()
+            {
+                { "createRole", roleManagerService.CreateRole },
+                { "getRole", roleManagerService.GetRole },
+                { "listRoles", async (payload, context) => await roleManagerService.ListRoles(context) },
+                { "updateRole", roleManagerService.UpdateRole },
+                { "deleteRole", roleManagerService.DeleteRole }
+            };
+        }
+
+        public async Task<ApiResponse> Execute(ApiRequest request, HttpContext httpContext)
+        {
+            if (!_functionHandler.TryGetValue(request.FunctionName, out var handler))
+            {
+                return new ApiResponse
+                {
+                    StatusCode = 404,
+                    Message = $"Function '{request.FunctionName}' not found.",
+                    Data = null
+                };
+            }
+            try
+            {
+                var results = await handler(request.Payload, httpContext);
+                return new ApiResponse
+                {
+                    StatusCode = 200,
+                    Message = "success",
+                    Data = results
+                };
+            }
+            catch (KeyNotFoundException ex)
+            {
+                return new ApiResponse
+                {
+                    StatusCode = 400,
+                    Message = ex.Message,
+                    Data = null
+                };
+            }
+            catch (InvalidOperationException ex)
+            {
+                return new ApiResponse
+                {
+                    StatusCode = 400,
+                    Message = ex.Message,
+                    Data = null
+                };
+            }
+            catch (ArgumentException ex)
+            {
+                return new ApiResponse
+                {
+                    StatusCode = 500,
+                    Message = ex.Message,
+                    Data = null
+                };
+            }
+        }
+    }
+}