fix(client): 自动连接竞态真因 — 等设置加载完再判(1.0.22)

日志实证:节点就绪(~450ms)与设置加载几乎同时完成,节点回调早 1ms 读到还没加载完的
autoConnect=false → 不连。AppSettings 加 loaded 标志(_load 完成置 true,失败也置);
_maybeAutoConnect 同时监听 nodes + settings,二者都就绪(settings.loaded && 节点 uuid 非空)
才决策一次。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/windows/installer/pangolin.iss

@@ -3,7 +3,7 @@
 ; 前置: 先在 client/ 跑 `flutter build windows`(Release),产物在
 ;       ..\..\build\windows\x64\runner\Release
 #define MyAppName "穿山甲 Pangolin"
-#define MyAppVersion "1.0.21"
+#define MyAppVersion "1.0.22"
 #define MyAppPublisher "Pangolin"
 #define MyAppExeName "pangolin_vpn.exe"
 #define BuildDir "..\..\build\windows\x64\runner\Release"