Update exam status display to show time until upcoming exams

frontend/src/pages/Home.tsx

@@ -2,7 +2,7 @@ import React, { useState, useEffect } from 'react';
 import axios from 'axios';
 import { toast } from 'react-toastify';
 import { Plus, Edit2, Trash2, Calendar, BookOpen, Loader2, Clock, ChevronDown, ChevronRight, Sparkles } from 'lucide-react';
-import { format, isFuture, differenceInCalendarDays } from 'date-fns';
+import { format, isFuture, differenceInCalendarDays, formatDistanceToNow } from 'date-fns';
 import { Exam, ApiResponse, User } from '../types';
 import ExamModal from '../modals/ExamModal';
 import ImportAIModal from '../modals/ImportAIModal';
@@ -111,7 +111,7 @@ function Home({ user }: HomeProps) {
               />
             </div>
             <div className={`px-3 py-1 text-[10px] font-bold tracking-widest rounded-full uppercase ${upcoming ? 'bg-apple-accent/20 text-apple-accent' : 'bg-white/10 text-apple-muted'}`}>
-              {upcoming ? 'Upcoming' : 'Passed'}
+              {upcoming ? formatDistanceToNow(examDate, { addSuffix: true }) : 'Passed'}
             </div>
           </div>