fix: 모바일 일정 HTML 엔티티 디코딩 적용

- decodeHtmlEntities 함수 추가
- ScheduleCard, TimelineScheduleCard title에 적용
- & → & 등으로 올바르게 표시

frontend/src/pages/mobile/public/Schedule.jsx

@@ -6,6 +6,14 @@ import { useInView } from 'react-intersection-observer';
 import { useVirtualizer } from '@tanstack/react-virtual';
 import { getSchedules, getCategories, searchSchedules } from '../../../api/public/schedules';
 
+// HTML 엔티티 디코딩 함수
+const decodeHtmlEntities = (text) => {
+    if (!text) return '';
+    const textarea = document.createElement('textarea');
+    textarea.innerHTML = text;
+    return textarea.value;
+};
+
 // 모바일 일정 페이지
 function MobileSchedule() {
     const [selectedDate, setSelectedDate] = useState(new Date());
@@ -570,7 +578,7 @@ function ScheduleCard({ schedule, categoryColor, categories, delay = 0 }) {
                     style={{ backgroundColor: categoryColor }}
                 />
                 <div className="flex-1 min-w-0">
-                    <h3 className="font-semibold text-sm">{schedule.title}</h3>
+                    <h3 className="font-semibold text-sm">{decodeHtmlEntities(schedule.title)}</h3>
                     <div className="flex flex-wrap items-center gap-2 mt-1 text-xs text-gray-500">
                         {schedule.time && (
                             <span className="flex items-center gap-1">
@@ -650,7 +658,7 @@ function TimelineScheduleCard({ schedule, categoryColor, categories, delay = 0 }
                 
                 {/* 제목 */}
                 <h3 className="font-bold text-[15px] text-gray-800 leading-snug">
-                    {schedule.title}
+                    {decodeHtmlEntities(schedule.title)}
                 </h3>
                 
                 {/* 출처 */}