feat: added session guid and token type fields to jwt tokens;

feat: very minimal implementation of registration functions;
refactor: login function now uses the transactional db helper function and creates a session;
feat: enum for jwt token type

backend/internal/utils/jwt.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/>.
 
@@ -19,22 +19,27 @@ package utils
 
 import (
 	"easywish/config"
+	"easywish/internal/utils/enums"
 	"time"
 
 	"github.com/golang-jwt/jwt/v5"
 )
 
-func GenerateTokens(username string) (accessToken, refreshToken string, err error) {
+func GenerateTokens(username string, sessionGuid string) (accessToken, refreshToken string, err error) {
 	cfg := config.GetConfig()
 
 	accessClaims := jwt.MapClaims{
 		"username": username,
+		"guid": sessionGuid,
+		"type": enums.JwtAccessTokenType,
 		"exp":     time.Now().Add(time.Minute * time.Duration(cfg.JwtExpAccess)).Unix(),
 	}
 	accessToken, err = jwt.NewWithClaims(jwt.SigningMethodHS256, accessClaims).SignedString([]byte(cfg.JwtSecret))
 
 	refreshClaims := jwt.MapClaims{
 		"username": username,
+		"guid": sessionGuid,
+		"type": enums.JwtRefreshTokenType,
 		"exp":     time.Now().Add(time.Hour * time.Duration(cfg.JwtExpRefresh)).Unix(),
 	}
 	refreshToken, err = jwt.NewWithClaims(jwt.SigningMethodHS256, refreshClaims).SignedString([]byte(cfg.JwtSecret))