perf: optimize app startup and background lifecycles

tests/e2e/popup-performance.spec.ts

@@ -24,7 +24,7 @@ async function readPopupStyles(page: Awaited<ReturnType<typeof getStableWindow>>
 }
 
 test.describe('shared popup rendering cost', () => {
-  test('disables transient popup backdrop filters only on macOS', async ({ launchElectronApp }) => {
+  test('disables transient popup backdrop filters on every platform', async ({ launchElectronApp }) => {
     const app = await launchElectronApp({ skipSetup: true });
 
     try {
@@ -41,9 +41,6 @@ test.describe('shared popup rendering cost', () => {
       await page.getByTestId('settings-reveal-additional').click();
       await expect(page.getByRole('dialog')).toBeVisible();
 
-      await page.evaluate(() => {
-        document.documentElement.dataset.platform = 'darwin';
-      });
       await expect.poll(() => readPopupStyles(page)).toEqual({
         contentBackdropFilter: 'none',
         overlayBackdropFilter: 'none',
@@ -52,9 +49,10 @@ test.describe('shared popup rendering cost', () => {
       await page.evaluate(() => {
         document.documentElement.dataset.platform = 'win32';
       });
-      const nonMacStyles = await readPopupStyles(page);
-      expect(nonMacStyles.contentBackdropFilter).not.toBe('none');
-      expect(nonMacStyles.overlayBackdropFilter).not.toBe('none');
+      await expect.poll(() => readPopupStyles(page)).toEqual({
+        contentBackdropFilter: 'none',
+        overlayBackdropFilter: 'none',
+      });
     } finally {
       await app.evaluate(({ app: electronApp }) => electronApp.quit());
     }