🐛 fix(window): 修复 Windows 恢复焦点后界面缩放异常

Fixes #315

frontend/src/utils/windowsScaleFix.ts

@@ -0,0 +1,46 @@
+type WindowsViewportScaleInput = {
+  windowWidth: number;
+  innerWidth: number;
+  devicePixelRatio: number;
+  visualViewportScale?: number | null;
+};
+
+export const computeWindowsViewportScaleRatio = ({
+  windowWidth,
+  innerWidth,
+  devicePixelRatio,
+}: WindowsViewportScaleInput): number => {
+  const normalizedWindowWidth = Number(windowWidth);
+  const normalizedInnerWidth = Number(innerWidth);
+  const normalizedDevicePixelRatio = Number(devicePixelRatio);
+  if (
+    !Number.isFinite(normalizedWindowWidth) || normalizedWindowWidth <= 0 ||
+    !Number.isFinite(normalizedInnerWidth) || normalizedInnerWidth <= 0 ||
+    !Number.isFinite(normalizedDevicePixelRatio) || normalizedDevicePixelRatio <= 0
+  ) {
+    return 1;
+  }
+  return (normalizedWindowWidth / normalizedDevicePixelRatio) / normalizedInnerWidth;
+};
+
+export const hasWindowsViewportScaleDrift = (
+  metrics: WindowsViewportScaleInput,
+  tolerance = 0.08,
+): boolean => {
+  const normalizedTolerance = Math.max(0.01, Number(tolerance) || 0.08);
+  const visualViewportScale = Number(metrics.visualViewportScale);
+  if (Number.isFinite(visualViewportScale) && Math.abs(visualViewportScale - 1) > normalizedTolerance) {
+    return true;
+  }
+
+  const viewportScaleRatio = computeWindowsViewportScaleRatio(metrics);
+  return Math.abs(viewportScaleRatio - 1) > normalizedTolerance;
+};
+
+export const getWindowsScaleFixNudgedWidth = (width: number): number => {
+  const normalizedWidth = Math.trunc(Number(width) || 0);
+  if (normalizedWidth <= 0) {
+    return 0;
+  }
+  return normalizedWidth > 480 ? normalizedWidth - 1 : normalizedWidth + 1;
+};