fix: 榜单云函数失败时仅无数据才提示toast，避免已有数据时误弹

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

config.js

@@ -4,7 +4,7 @@
  */
 module.exports = {
   /** 应用版本号，外显在设置页「关于」 */
-  version: 'v1.5',
+  version: 'v2.0',
 
   /** 最后更新日期，外显在设置页「关于」 */
   updatedAt: '2026-06-24',

pages/leaderboard/leaderboard.js

@@ -66,10 +66,14 @@ Page({
       if (cb) cb()
     }).catch((err) => {
       // Cloud function not deployed or network error — fall back to
-      // local data but let the user know the leaderboard is degraded.
+      // local data. Only show a toast if we have nothing to display
+      // yet (avoid confusing toast when a retry already has data).
       console.warn('[leaderboard] cloud function failed, using local fallback:', err)
-      wx.showToast({ title: '云端榜单暂不可用', icon: 'none', duration: 2000 })
+      const hadData = this.data.rankedList && this.data.rankedList.length > 0
       this._applyLocal()
+      if (!hadData && (!this.data.rankedList || this.data.rankedList.length === 0)) {
+        wx.showToast({ title: '云端榜单暂不可用', icon: 'none', duration: 2000 })
+      }
       if (cb) cb()
     })
   },