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/UserManager.cs

@@ -18,19 +18,13 @@ namespace AuthHex.Services.FunctionHandler
                 { "refreshToken", UserManagerService.RefreshToken },
                 { "getUserDetails", UserManagerService.GetUserDetails }, 
                 { "getUserSessions", async (payload, context) => await UserManagerService.GetUserSessions(context)  },
-                { "listUserTypes", async (payload, context) => await UserManagerService.ListUserTypes(context) },
-                { "ChangeUserStatus", UserManagerService.ChangeUserStatus},
+{ "ChangeUserStatus", UserManagerService.ChangeUserStatus},
                 {"LockUserAccount" , UserManagerService.LockUserAccount  },
                 {"ChangeUserPassword" , UserManagerService.ChangeUserPassword  },
                 {"VerifyPassword" , UserManagerService.VerifyPassword  },
                 {"LogoutUser" , UserManagerService.LogoutUser},
                 {"UpdateUser", UserManagerService.UpdateUser},
                 {"VerifyOtpForLogin",UserManagerService.VerifyOtpForLogin},
-
-                // Admin-only — require X-Admin-Api-Key, act on an arbitrary target user.
-                {"AdminUpdateUser", UserManagerService.AdminUpdateUser},
-                {"AdminSetUserStatus", UserManagerService.AdminSetUserStatus},
-                {"deleteUser", UserManagerService.DeleteUser},
                 
                 // 2FA Management Functions
                 { "initiateTwoFASetup", async (payload, context) => await UserManagerService.InitiateTwoFASetup(context) },
@@ -62,15 +56,6 @@ namespace AuthHex.Services.FunctionHandler
                     Data = results
                 };
             }
-            catch (UnauthorizedAccessException ex)
-            {
-                return new ApiResponse
-                {
-                    StatusCode = 401,
-                    Message = ex.Message,
-                    Data = null
-                };
-            }
             catch (KeyNotFoundException ex)
             {
                 return new ApiResponse