feat: phase 2 - polls, memories, notifications, stats v0.1.0

- Group polls with option/rollcall modes, edit by creator, auto-settle
- Multimedia memories with upload, preview, inline video playback
- In-app notifications for poll/team/group events
- Points system and group stats dashboard
- Group detail tabs with icons (activity/polls/memories/stats)
- Fix: nginx file upload size, static cache blocking API, timezone, auto-cancel

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/views/Changelog.vue

@@ -10,6 +10,24 @@ interface LogEntry {
 }
 
 const logs = ref<LogEntry[]>([
+  {
+    version: 'v0.1.0',
+    date: '2026-04-18',
+    title: '二期功能：投票、回忆、统计',
+    items: [
+      { type: 'feat', text: '群组投票：支持选项投票和接龙报名两种模式，可设置截止时间、匿名投票' },
+      { type: 'feat', text: '投票编辑：发起人可修改标题、选项、截止时间，已投票选项不可删除' },
+      { type: 'feat', text: '投票结算：到达截止时间自动结算，发起人也可手动结束投票' },
+      { type: 'feat', text: '多媒体回忆：群组内上传图片/视频/音频/文档，缩略图预览和弹窗播放' },
+      { type: 'feat', text: '数据统计：群组内展示本周组队次数、投票参与率、积分排行' },
+      { type: 'feat', text: '站内通知：新增投票、组队、入群等场景通知，铃铛图标显示未读数' },
+      { type: 'feat', text: '积分体系：参与投票/组队/上传获取积分，群组内展示排行' },
+      { type: 'feat', text: '群组详情页 Tab 重构：动态/投票/回忆/统计四个 Tab，带图标醒目展示' },
+      { type: 'fix', text: '修复 nginx 代理文件上传 413 问题和静态资源误拦截 API 文件请求' },
+      { type: 'fix', text: '修复投票列表 auto-cancel 竞态问题和选项排序 0 值校验失败' },
+      { type: 'fix', text: '修复截止时间时区偏差，统一使用 ISO 格式存储' },
+    ]
+  },
   {
     version: 'v0.0.3',
     date: '2026-04-18',