fix(client): 自动连接死锁兜底(轮询)+ 逐次门控日志(1.0.27)

复现:armed→设置已加载后无 ready。死锁:selLoaded 靠 selectedNode controller 的 loaded 标志,
而该标志完成时若选中值未变(==默认)不会发通知,若 nodeSub 已先于它触发则此后无人再调 tryGo。
修:_maybeAutoConnect 加 Timer.periodic(400ms,≤12s)兜底复查,decided 后停;并恢复每次 tryGo
打 check 日志(settingsLoaded/selLoaded/node uuid)以确认卡点。

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 "1.0.26"
+#define MyAppVersion "1.0.27"
 #define MyAppPublisher "Pangolin"
 #define MyAppExeName "pangolin_vpn.exe"
 #define BuildDir "..\..\build\windows\x64\runner\Release"