feat(ui): 添加全局图标配置并优化弹窗图标显示

将图标加载逻辑提取到 GlobalConfig 中统一管理，并在登录失败弹窗及 Cookie更新完成弹窗中设置应用图标。同时修复了部分弹窗文本描述不一致的问题。

src/main/java/com/fantaibao/config/GlobalConfig.java

@@ -1,5 +1,12 @@
 package com.fantaibao.config;
 
+import javafx.scene.image.Image;
+import javafx.stage.Stage;
+import org.springframework.util.ResourceUtils;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+
 public class GlobalConfig {
     /**
     * 基础网络地址
@@ -46,4 +53,23 @@ public class GlobalConfig {
     */
     public static String dyLoginPage;
 
+
+
+    public static final Image icon16;
+    public static final Image icon32;
+
+    static {
+        try {
+            icon16 = new Image(new FileInputStream(ResourceUtils.getFile("classpath:icon16.png")));
+            icon32 = new Image(new FileInputStream(ResourceUtils.getFile("classpath:icon32.png")));
+        } catch (FileNotFoundException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void addIcon(Stage stage) {
+        stage.getIcons().add(GlobalConfig.icon16);
+        stage.getIcons().add(GlobalConfig.icon32);
+    }
+
 }