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>

cloudfunctions/getHotTopics/index.js

@@ -0,0 +1,32 @@
+const cloud = require('wx-server-sdk')
+cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
+const db = cloud.database()
+const SCAN_LIMIT = 200
+const TOP_N = 10
+
+exports.main = async (event, context) => {
+  try {
+    const res = await db.collection('posts')
+      .orderBy('createdAt', 'desc')
+      .limit(SCAN_LIMIT)
+      .field({ hashtags: true })
+      .get()
+
+    const counts = {}
+    res.data.forEach(p => {
+      ;(p.hashtags || []).forEach(tag => {
+        if (!tag) return
+        counts[tag] = (counts[tag] || 0) + 1
+      })
+    })
+
+    const topics = Object.keys(counts)
+      .map(tag => ({ tag, count: counts[tag] }))
+      .sort((a, b) => b.count - a.count)
+      .slice(0, TOP_N)
+
+    return { code: 0, data: topics }
+  } catch (e) {
+    return { code: -1, message: e.message }
+  }
+}

cloudfunctions/getHotTopics/package.json

@@ -0,0 +1 @@
+{ "name": "getHotTopics", "version": "1.0.0", "main": "index.js", "dependencies": { "wx-server-sdk": "~2.1.2" } }