fix(web): hide mobile backdrop on desktop

apps/web_v1/scripts/visual-check.mjs

@@ -240,6 +240,26 @@ if (await projectNavButton.count() === 0) {
   if (!await page.locator('aside.project-rail.open').isVisible()) {
     failures.push('打开项目导航 must reveal the project rail aside')
   }
+  await page.setViewportSize({ width: 1440, height: 1024 })
+  const resizedDesktopMetrics = await collectMetrics()
+  const desktopBackdropDisplay = await page.locator('.nav-backdrop').evaluate((node) => getComputedStyle(node).display)
+  if (desktopBackdropDisplay !== 'none') {
+    failures.push(`navigation backdrop must be hidden after resizing to desktop, got display=${desktopBackdropDisplay}`)
+  }
+  if (resizedDesktopMetrics.overflowX) {
+    failures.push('resized desktop project viewport must not overflow horizontally')
+  }
+  if (!resizedDesktopMetrics.projectRail || !resizedDesktopMetrics.channelSidebar || !resizedDesktopMetrics.stage) {
+    failures.push('resized desktop must preserve project rail, channel sidebar, and stage')
+  } else if (
+    Math.abs(resizedDesktopMetrics.channelSidebar.left - resizedDesktopMetrics.projectRail.right) > 1 ||
+    Math.abs(resizedDesktopMetrics.stage.left - resizedDesktopMetrics.channelSidebar.right) > 1 ||
+    Math.abs(resizedDesktopMetrics.stage.right - resizedDesktopMetrics.viewportWidth) > 1
+  ) {
+    failures.push(`resized desktop layout must preserve the core grid, got rail=${JSON.stringify(resizedDesktopMetrics.projectRail)}, sidebar=${JSON.stringify(resizedDesktopMetrics.channelSidebar)}, stage=${JSON.stringify(resizedDesktopMetrics.stage)}`)
+  }
+  await page.setViewportSize({ width: 390, height: 844 })
+  await waitForDrawerOpen('aside.project-rail')
   await page.getByRole('button', { name: '关闭导航', exact: true }).click({ position: { x: 380, y: 20 } })
 }