chore: 清理冗余代码并补全私信/搜索/故事/通知功能

- 删除未使用的空组件目录、死代码导出(clearAuth/calcDistance/COLORS/
  AVATAR_GRADIENTS/Message/TabBarItem/deletePost/uploadImage/getFileURL/
  _initLogin)，确保程序仍可正常运行
- 新增 8 个云函数并补全对应页面逻辑：getMessages/sendMessage(私信聊天)、
  getHotTopics/searchPosts/searchUsers(搜索)、getStory(故事，复用 posts
  集合)、getNotifications/markAllRead(基于点赞评论聚合的通知系统)
- 在 cloudbaserc.json 中注册全部新云函数，并通过 --deployMode zip 完成部署

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

cloudbaserc.json

@@ -114,6 +114,62 @@
       "runtime": "Nodejs20.19",
       "handler": "index.main",
       "description": "删除宠物档案"
+    },
+    {
+      "name": "getMessages",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "获取与某用户的聊天消息列表"
+    },
+    {
+      "name": "sendMessage",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "发送私信消息"
+    },
+    {
+      "name": "getHotTopics",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "获取热门话题标签"
+    },
+    {
+      "name": "searchPosts",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "搜索帖子"
+    },
+    {
+      "name": "searchUsers",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "搜索用户"
+    },
+    {
+      "name": "getStory",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "获取用户故事(最近带图动态)"
+    },
+    {
+      "name": "getNotifications",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "获取通知列表(点赞/评论聚合)"
+    },
+    {
+      "name": "markAllRead",
+      "timeout": 10,
+      "runtime": "Nodejs20.19",
+      "handler": "index.main",
+      "description": "标记全部通知已读"
     }
   ]
 }