refactor/fix: now using pgx errors for postgres error checking instead of trying to look up the error code;

feat: implemented working custom validation;
fix: authservice begin/complete registration

backend/cmd/main.go

@@ -1,17 +1,17 @@
 // Copyright (c) 2025 Nikolai Papin
-// 
+//
 // This file is part of Easywish
-// 
+//
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
-// 
+//
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 // the GNU General Public License for more details.
-// 
+//
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
@@ -46,6 +46,7 @@ import (
 	"easywish/internal/logger"
 	"easywish/internal/routes"
 	"easywish/internal/services"
+	"easywish/internal/validation"
 
 	swaggerfiles "github.com/swaggo/files"
 	ginSwagger "github.com/swaggo/gin-swagger"
@@ -65,6 +66,8 @@ func main() {
 		),
 		database.Module,
 		services.Module,
+		validation.Module,
+
 		controllers.Module,
 		routes.Module,