feat: Add refresh token endpoint and remember me support

- Add POST /auth/refresh endpoint for token renewal
- Only set refresh token cookie when rememberMe is true
- Add rememberMe field to login validator schema

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/controllers/auth.controller.js

@@ -6,13 +6,15 @@ import {
   logLogin,
   logLogout,
 } from '../services/audit.service.js';
+import { verifyRefreshToken, generateAccessToken } from '../utils/jwt.js';
+import { getUserById } from '../services/auth.service.js';
 
 /**
  * KROK 1: Login s temporary password
  * POST /api/auth/login
  */
 export const login = async (req, res, next) => {
-  const { username, password } = req.body;
+  const { username, password, rememberMe } = req.body;
   const ipAddress = req.ip || req.connection.remoteAddress;
   const userAgent = req.headers['user-agent'];
 
@@ -37,12 +39,15 @@ export const login = async (req, res, next) => {
       maxAge: 60 * 60 * 1000, // 1 hodina
     });
 
-    res.cookie('refreshToken', result.tokens.refreshToken, {
-      httpOnly: true,
-      secure: isProduction,
-      sameSite: isProduction ? 'strict' : 'lax',
-      maxAge: 7 * 24 * 60 * 60 * 1000, // 7 dní
-    });
+    // Refresh token iba ak user chce zostať prihlásený
+    if (rememberMe) {
+      res.cookie('refreshToken', result.tokens.refreshToken, {
+        httpOnly: true,
+        secure: isProduction,
+        sameSite: isProduction ? 'strict' : 'lax',
+        maxAge: 7 * 24 * 60 * 60 * 1000, // 7 dní
+      });
+    }
 
     res.status(200).json({
       success: true,
@@ -62,6 +67,68 @@ export const login = async (req, res, next) => {
   }
 };
 
+/**
+ * Refresh access token using refresh token
+ * POST /api/auth/refresh
+ */
+export const refreshToken = async (req, res, next) => {
+  try {
+    const token = req.cookies?.refreshToken;
+
+    if (!token) {
+      return res.status(401).json({
+        success: false,
+        error: {
+          message: 'Refresh token nie je k dispozícii',
+          statusCode: 401,
+        },
+      });
+    }
+
+    // Verify refresh token
+    const decoded = verifyRefreshToken(token);
+
+    // Get user from DB
+    const user = await getUserById(decoded.id);
+
+    // Generate new access token
+    const newAccessToken = generateAccessToken({
+      id: user.id,
+      username: user.username,
+      role: user.role,
+    });
+
+    // Set new access token cookie
+    const isProduction = process.env.NODE_ENV === 'production';
+    res.cookie('accessToken', newAccessToken, {
+      httpOnly: true,
+      secure: isProduction,
+      sameSite: isProduction ? 'strict' : 'lax',
+      maxAge: 60 * 60 * 1000, // 1 hodina
+    });
+
+    res.status(200).json({
+      success: true,
+      data: {
+        accessToken: newAccessToken,
+      },
+      message: 'Token obnovený',
+    });
+  } catch (error) {
+    // Clear invalid cookies
+    res.clearCookie('accessToken');
+    res.clearCookie('refreshToken');
+
+    return res.status(401).json({
+      success: false,
+      error: {
+        message: 'Refresh token expiroval alebo je neplatný',
+        statusCode: 401,
+      },
+    });
+  }
+};
+
 /**
  * KROK 2: Nastavenie nového hesla
  * POST /api/auth/set-password

src/routes/auth.routes.js

@@ -25,6 +25,9 @@ router.post(
   authController.login
 );
 
+// Refresh access token (public - uses refresh token from cookie)
+router.post('/refresh', authController.refreshToken);
+
 /**
  * Protected routes (vyžadujú autentifikáciu)
  */

src/validators/auth.validators.js

@@ -15,6 +15,7 @@ export const loginSchema = z.object({
       invalid_type_error: 'Heslo musí byť text',
     })
     .min(1, 'Heslo nemôže byť prázdne'),
+  rememberMe: z.boolean().optional().default(false),
 });
 
 // Set new password schema (krok 2)