fix: v0.4.1 修复主题切换丢 swatch 底色与连接失败长错误串撑爆布局；新增 selftest_theme；重打包

DLPilot/src/dlpc_rs485.py

@@ -326,11 +326,19 @@ class DLPC485:
                         self.ser = None
                         with self._lock:
                             self._target = None
-                        et = str(e)
-                        if 'PermissionError' in repr(e) or '拒绝访问' in et \
-                                or 'Access is denied' in et:
-                            et += '（串口被占用: 检查串口助手/另一个本工具实例）'
-                        self.on_status(f'连接失败: {et}')
+                        blob = str(e) + repr(e)
+                        if 'PermissionError' in blob or '拒绝访问' in blob \
+                                or 'Access is denied' in blob:
+                            hint = '串口被占用（串口助手/另一实例?）'
+                        elif 'FileNotFoundError' in blob or '找不到指定的' in blob \
+                                or 'No such file' in blob:
+                            hint = '串口不存在，请刷新后重选'
+                        else:
+                            hint = '无法打开，详情见日志'
+                        # 状态标签只放短提示(长异常串会撑爆参数行把窗口拉长),
+                        # 完整异常走 on_event 进收发日志
+                        self.on_status(f'连接失败: {hint}')
+                        self.on_event(f'连接失败: {e!r}')
             if self.ser is not None:
                 try:
                     item = None