接入自建后端 + Gitea CI/CD

- 新增 server/：Node + Express + SQLite + node-cron 实现登录、纪念日 CRUD 和定时订阅消息推送
- 新增 .gitea/workflows/deploy.yml：推送即触发群晖 Docker 部署，监听 15002
- utils/api.js：自动按 envVersion 切换本地/线上 BASE_URL
- app.js 与 add-anniversary.js 移除 wx.cloud 调用，改走自建后端
- cloudfunctions/ 暂保留以便回滚
- 一并提交此前未入库的首页 / 设置页 / 日历 / 万年历等改造

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app.json

@@ -16,27 +16,21 @@
   },
   "tabBar": {
     "color": "#7A7E83",
-    "selectedColor": "#3cc51f",
+    "selectedColor": "#07c160",
     "borderStyle": "black",
     "backgroundColor": "#ffffff",
     "list": [
       {
         "pagePath": "pages/index/index",
-        "iconPath": "/images/home.png",
-        "selectedIconPath": "/images/home-active.png",
-        "text": "首页"
+        "text": "🏠 首页"
       },
       {
         "pagePath": "pages/calendar/calendar",
-        "iconPath": "/images/calendar.png",
-        "selectedIconPath": "/images/calendar-active.png",
-        "text": "日历"
+        "text": "📅 日历"
       },
       {
         "pagePath": "pages/settings/settings",
-        "iconPath": "/images/settings.png",
-        "selectedIconPath": "/images/settings-active.png",
-        "text": "设置"
+        "text": "⚙️ 设置"
       }
     ]
   },