feat: Centralized navigation system with HandleNavigate hook

BREAKING CHANGE: Replaced all direct useNavigate() usage with HandleNavigate hook

## Summary
- Complete frontend navigation refactoring
- Centralized route management with routes.js
- Converted 18+ components to use HandleNavigate
- Enhanced navigation with 20+ type-safe functions

## New Files
- src/utils/routes.js - Central route constants and helpers
- Documentations/FRONTEND_CODING_GUIDELINES.md - Frontend best practices (300+ lines)
- Documentations/NAVIGATION_REFACTORING_REPORT.md - Detailed refactoring report (400+ lines)

## Modified Components (18+)
### Pages
- Home.jsx, LoginForm.jsx, RegisterForm.jsx
- ResetPassword.jsx, VerifyEmailPage.jsx
- DeckCreator.jsx, Card_display.jsx
- Lobby.jsx, GameTest.jsx, ChooseDeck.jsx, PlayerSetup.jsx
- Landingpage.jsx

### Components
- Userdetails.jsx, DeckInfoPopUp.jsx
- PlayMenu.jsx, LandingPage.jsx, DeckManager.jsx

### Hooks
- useRequireAuth.jsx

### Core
- App.jsx - Route constants integration
- HandleNavigate.jsx - Enhanced with 20+ navigation functions

## Key Improvements
 Type-safe navigation (goDeckDetails(id) vs navigate('/deck/'+id))
 Automatic scroll management
 Centralized state passing
 Single source of truth for routes
 Backwards compatibility aliases
 Zero compile errors
 Production ready

## Validation
- useNavigate: Only in HandleNavigate.jsx
- navigate() calls: 0 direct usage
- Compile errors: 0
- Documentation: Complete

SerpentRace_Frontend/src/pages/Auth/LoginForm.jsx

@@ -3,7 +3,8 @@ import InputBox from "../../components/Inputs/InputBox"
 import Button from "../../components/Buttons/Button"
 import { motion } from "framer-motion"
 import { useState, useEffect } from "react"
-import { useLocation, useNavigate } from "react-router-dom"
+import { useLocation } from "react-router-dom"
+import HandleNavigate from "../../utils/HandleNavigate/HandleNavigate"
 import { login, forgotPassword } from "../../api/userApi"
 import { FaArrowLeft } from "react-icons/fa"
 
@@ -12,7 +13,7 @@ export default function LoginForm() {
   const [password, setPassword] = useState("")
   const [error, setError] = useState("")
   const location = useLocation()
-  const navigate = useNavigate()
+  const { goHome, goLanding } = HandleNavigate()
   const [showSuccess, setShowSuccess] = useState(false)
   const [showErrorPopup, setShowErrorPopup] = useState(false)
   const [showForgotPasswordModal, setShowForgotPasswordModal] = useState(false)
@@ -63,7 +64,7 @@ export default function LoginForm() {
             localStorage.setItem("username", response.data.user.username)
             localStorage.setItem("authLevel", response.data.user.authLevel)
           }
-          navigate("/home")
+          goHome()
         } else {
           setError("Hibás bejelentkezési adatok.")
           setShowErrorPopup(true)
@@ -115,7 +116,7 @@ export default function LoginForm() {
       {/* 🔙 Vissza nyíl gomb — most pontosan a fehér box bal felső sarkában */}
       <div
         className="absolute -top-6 -left-6 flex items-center group cursor-pointer select-none"
-        onClick={() => navigate("/")}
+        onClick={() => goLanding()}
       >
         <FaArrowLeft className="text-gray-700 text-xl transition-transform duration-300 group-hover:-translate-x-1" />
         <span className="ml-2 text-gray-700 font-medium opacity-0 -translate-x-2 group-hover:opacity-100 group-hover:translate-x-0 transition-all duration-300">