feat: Implement password reset and change functionality

Co-authored-by: mathieumoran1 <[email protected]>

public/js/app_register.js

@@ -1,8 +1,24 @@
+function decodeJwt(token) {
+  return JSON.parse(atob(token.split('.')[1]));
+}
+
 // Check if the user is already logged in by looking for auth_token in localStorage
-if (localStorage.getItem('auth_token')) {
-    // If the token is found, redirect to /movies.html
-    window.location.href = '/movies.html';
+const existingToken = localStorage.getItem('auth_token');
+if (existingToken) {
+  try {
+    const decoded = decodeJwt(existingToken);
+    const currentTime = Math.floor(Date.now() / 1000);
+    if (decoded.exp && decoded.exp < currentTime) {
+      localStorage.removeItem('auth_token');
+    } else if (decoded.mustChangePassword) {
+      window.location.href = '/change-password.html';
+    } else {
+      window.location.href = '/movies.html';
+    }
+  } catch (_) {
+    localStorage.removeItem('auth_token');
   }
+}
 
   // Handle registration form submission
   document.getElementById('register-form').addEventListener('submit', async function (e) {