🐛 fix(window): 修复 Windows 最大化还原后文字变大

- 将缩放修正改为去抖检查，避免 focus/resize/visibilitychange 连续触发
- 最大化/还原改为显式切换窗口状态，减少重复 toggle 带来的抖动
- 补充 Windows 缩放修正相关工具测试

frontend/src/utils/windowStateUi.ts

@@ -1,11 +1,17 @@
 export type WindowVisualState = 'normal' | 'maximized' | 'fullscreen';
 export type WindowScaleFixReason = 'activation' | 'ratio-change';
+export type WindowsScaleCheckTrigger = 'focus' | 'pageshow' | 'poll' | 'resize' | 'visibilitychange';
 export type TitleBarToggleIconKey = 'maximize' | 'restore';
 
-export const shouldToggleMaximisedWindowForScaleFix = (
+export const shouldApplyWindowsScaleFix = (
   reason: WindowScaleFixReason,
   hasViewportScaleDrift: boolean,
 ): boolean => reason === 'ratio-change' && hasViewportScaleDrift;
 
+export const shouldToggleMaximisedWindowForScaleFix = shouldApplyWindowsScaleFix;
+
+export const resolveWindowsScaleCheckDelayMs = (trigger: WindowsScaleCheckTrigger): number =>
+  trigger === 'resize' ? 240 : 0;
+
 export const resolveTitleBarToggleIconKey = (windowState: WindowVisualState): TitleBarToggleIconKey =>
   windowState === 'maximized' ? 'restore' : 'maximize';