feat: 모바일 일정 상세 페이지 및 에러 UI 추가

- MobileScheduleDetail 컴포넌트 생성
- 404 에러 페이지 UI (애니메이션 포함)
- /schedule/:id 라우트 추가

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

frontend/src/App.jsx

@@ -25,6 +25,7 @@ import MobileAlbumDetail from './pages/mobile/public/AlbumDetail';
 import MobileAlbumGallery from './pages/mobile/public/AlbumGallery';
 import MobileTrackDetail from './pages/mobile/public/TrackDetail';
 import MobileSchedule from './pages/mobile/public/Schedule';
+import MobileScheduleDetail from './pages/mobile/public/ScheduleDetail';
 import MobileNotFound from './pages/mobile/public/NotFound';
 
 // 관리자 페이지
@@ -104,6 +105,7 @@ function App() {
                     <Route path="/album/:name/gallery" element={<MobileLayout pageTitle="앨범"><MobileAlbumGallery /></MobileLayout>} />
                     <Route path="/album/:name/track/:trackTitle" element={<MobileLayout pageTitle="앨범"><MobileTrackDetail /></MobileLayout>} />
                     <Route path="/schedule" element={<MobileLayout useCustomLayout><MobileSchedule /></MobileLayout>} />
+                    <Route path="/schedule/:id" element={<MobileScheduleDetail />} />
                     <Route path="*" element={<MobileNotFound />} />
                 </Routes>
             </MobileView>

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

@@ -0,0 +1,119 @@
+import { useParams, Link } from 'react-router-dom';
+import { useQuery } from '@tanstack/react-query';
+import { motion } from 'framer-motion';
+import { Calendar, ChevronLeft } from 'lucide-react';
+import { getSchedule } from '../../../api/public/schedules';
+
+function MobileScheduleDetail() {
+    const { id } = useParams();
+
+    const { data: schedule, isLoading, error } = useQuery({
+        queryKey: ['schedule', id],
+        queryFn: () => getSchedule(id),
+        retry: false,
+    });
+
+    if (isLoading) {
+        return (
+            <div className="min-h-screen flex items-center justify-center bg-gray-50">
+                <div className="w-8 h-8 border-2 border-primary border-t-transparent rounded-full animate-spin" />
+            </div>
+        );
+    }
+
+    if (error || !schedule) {
+        return (
+            <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-gray-50 to-gray-100 px-6">
+                <div className="text-center">
+                    {/* 아이콘 */}
+                    <motion.div
+                        initial={{ opacity: 0, scale: 0.5 }}
+                        animate={{ opacity: 1, scale: 1 }}
+                        transition={{ duration: 0.5, type: "spring", stiffness: 100 }}
+                        className="mb-6"
+                    >
+                        <div className="w-24 h-24 mx-auto bg-gradient-to-br from-primary/10 to-primary/5 rounded-2xl flex items-center justify-center">
+                            <Calendar size={48} className="text-primary/40" />
+                        </div>
+                    </motion.div>
+
+                    {/* 메시지 */}
+                    <motion.div
+                        initial={{ opacity: 0, y: 20 }}
+                        animate={{ opacity: 1, y: 0 }}
+                        transition={{ delay: 0.2, duration: 0.5 }}
+                        className="mb-6"
+                    >
+                        <h2 className="text-xl font-bold text-gray-800 mb-2">
+                            일정을 찾을 수 없습니다
+                        </h2>
+                        <p className="text-gray-500 text-sm leading-relaxed">
+                            요청하신 일정이 존재하지 않거나
+                            <br />
+                            삭제되었을 수 있습니다.
+                        </p>
+                    </motion.div>
+
+                    {/* 장식 요소 */}
+                    <motion.div
+                        initial={{ opacity: 0 }}
+                        animate={{ opacity: 1 }}
+                        transition={{ delay: 0.4, duration: 0.5 }}
+                        className="flex justify-center gap-1.5 mb-8"
+                    >
+                        {[...Array(5)].map((_, i) => (
+                            <motion.div
+                                key={i}
+                                className="w-1.5 h-1.5 rounded-full bg-primary"
+                                animate={{
+                                    y: [0, -6, 0],
+                                    opacity: [0.3, 1, 0.3],
+                                }}
+                                transition={{
+                                    duration: 1.2,
+                                    repeat: Infinity,
+                                    delay: i * 0.15,
+                                    ease: "easeInOut",
+                                }}
+                            />
+                        ))}
+                    </motion.div>
+
+                    {/* 버튼들 */}
+                    <motion.div
+                        initial={{ opacity: 0, y: 20 }}
+                        animate={{ opacity: 1, y: 0 }}
+                        transition={{ delay: 0.5, duration: 0.5 }}
+                        className="flex flex-col gap-3"
+                    >
+                        <button
+                            onClick={() => window.history.back()}
+                            className="flex items-center justify-center gap-2 w-full px-6 py-3 border-2 border-primary text-primary rounded-full font-medium active:bg-primary active:text-white transition-colors"
+                        >
+                            <ChevronLeft size={18} />
+                            이전 페이지
+                        </button>
+                        <Link
+                            to="/schedule"
+                            className="flex items-center justify-center gap-2 w-full px-6 py-3 bg-gradient-to-r from-primary to-primary-dark text-white rounded-full font-medium active:opacity-90 transition-opacity"
+                        >
+                            <Calendar size={18} />
+                            일정 목록
+                        </Link>
+                    </motion.div>
+                </div>
+            </div>
+        );
+    }
+
+    // TODO: 일정 상세 페이지 구현
+    return (
+        <div className="min-h-screen bg-gray-50 p-4">
+            <div className="text-center py-8 text-gray-500">
+                일정 상세 페이지 준비 중
+            </div>
+        </div>
+    );
+}
+
+export default MobileScheduleDetail;