fix: 콘텐츠 캘린더 흐림 현상 완전 해결 — motion 제거

framer-motion animate가 프로덕션 빌드에서 완료되지 않는 문제로
SectionWrapper/ContentCalendar의 opacity:0 initial 상태가 유지됨.
motion.div/motion.button/motion.section을 일반 태그로 교체하고
모든 opacity 진입 애니메이션 제거.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/plan/ContentCalendar.tsx

@@ -1,6 +1,5 @@
 import React, { useState, useCallback } from 'react';
 import { exportCalendarToICS } from '../../lib/calendarExport';
-import { motion } from 'motion/react';
 import {
   VideoFilled,
   FileTextFilled,
@@ -313,22 +312,19 @@ export default function ContentCalendar({ data, planId, onEntryUpdate }: Content
           const Icon = contentTypeIcons[item.type];
           const isActive = filterType === item.type;
           return (
-            <motion.button
+            <button
               key={item.type}
               className={`flex items-center gap-3 px-5 py-3 rounded-2xl border cursor-pointer transition-all ${colors.bg} ${colors.border} ${colors.shadow} ${
                 isActive ? 'ring-2 ring-white/40 ring-offset-2 ring-offset-transparent' : ''
               } ${filterType && !isActive ? 'opacity-40' : ''}`}
               onClick={() => toggleFilter(item.type)}
-              initial={{ opacity: 0, y: 10 }}
-              animate={{ opacity: 1, y: 0 }}
-              transition={{ duration: 0.3, delay: i * 0.07 }}
             >
               <Icon size={16} className={`${colors.text} opacity-70`} />
               <div className="flex flex-col items-start">
                 <span className={`text-2xl font-bold leading-none ${colors.text}`}>{item.count}</span>
                 <span className={`text-xs font-medium ${colors.text} opacity-70 mt-0.5`}>{item.label}</span>
               </div>
-            </motion.button>
+            </button>
           );
         })}
         {filterType && (
@@ -357,12 +353,9 @@ export default function ContentCalendar({ data, planId, onEntryUpdate }: Content
           }
 
           return (
-            <motion.div
+            <div
               key={week.weekNumber}
               className="bg-white rounded-2xl p-5 mb-4 shadow-[3px_4px_12px_rgba(0,0,0,0.06)]"
-              initial={{ opacity: 0, y: 20 }}
-              animate={{ opacity: 1, y: 0 }}
-              transition={{ duration: 0.4, delay: weekIdx * 0.1 }}
             >
               <p className="text-sm font-bold text-[#0A1128] mb-3">{week.label}</p>
 
@@ -407,7 +400,7 @@ export default function ContentCalendar({ data, planId, onEntryUpdate }: Content
                 </svg>
                 콘텐츠 추가
               </button>
-            </motion.div>
+            </div>
           );
         })
       )}