fix(editor): ci stability (#14704)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Chores**
* Improved Electron shutdown, diagnostics and tab teardown for more
reliable exits and forced cleanup on stubborn processes.
* **Tests**
* Added polling-based test helpers, stronger scroll/page readiness,
timeout-tolerant page selection, and async cleanup/worker teardown;
updated many tests to wait for UI/model updates and rendering frames.
* **Bug Fixes**
* Reduced flakiness by awaiting paragraph visibility, nested counts,
selection/navigation stability, tab counts, post-action renders, and
safer element interactions.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/blocksuite/e2e/utils/actions/edgeless.ts

@@ -376,13 +376,28 @@ export async function setEdgelessTool(
         'shape',
         false
       );
-      // Avoid clicking on the shape-element (will trigger dragging mode)
-      await shapeToolButton.click({ position: { x: 5, y: 5 } });
+      const shapeToolBox = await shapeToolButton.boundingBox();
+      if (!shapeToolBox) {
+        throw new Error('shapeToolBox is not found');
+      }
 
-      const squareShapeButton = page
-        .locator('edgeless-slide-menu edgeless-tool-icon-button')
+      await page.mouse.click(shapeToolBox.x + 2, shapeToolBox.y + 2);
+
+      const shapeMenu = page.locator('edgeless-shape-menu');
+      await expect(shapeMenu).toBeVisible();
+
+      const squareShapeButton = shapeMenu
+        .locator('edgeless-tool-icon-button')
         .filter({ hasText: shape });
-      await squareShapeButton.click();
+      await expect(squareShapeButton).toBeVisible();
+      const squareShapeBox = await squareShapeButton.boundingBox();
+      if (!squareShapeBox) {
+        throw new Error('squareShapeBox is not found');
+      }
+      await page.mouse.click(
+        squareShapeBox.x + squareShapeBox.width / 2,
+        squareShapeBox.y + squareShapeBox.height / 2
+      );
       break;
     }
   }

tests/blocksuite/e2e/utils/actions/misc.ts

@@ -549,6 +549,7 @@ export async function focusRichText(
   await page.mouse.move(0, 0);
   const editor = getEditorHostLocator(page);
   const locator = editor.locator(RICH_TEXT_SELECTOR).nth(i);
+  await expect(locator).toBeVisible();
   // need to set `force` to true when clicking on `affine-selected-blocks`
   await locator.click({ force: true, position: options?.clickPosition });
 }
@@ -1229,43 +1230,37 @@ export async function getCurrentThemeCSSPropertyValue(
 }
 
 export async function scrollToTop(page: Page) {
-  await page.mouse.wheel(0, -1000);
-
-  await page.waitForFunction(() => {
-    const scrollContainer = document.querySelector('.affine-page-viewport');
-    if (!scrollContainer) {
-      throw new Error("Can't find scroll container");
-    }
-    return scrollContainer.scrollTop < 10;
+  const scrollContainer = page.locator('.affine-page-viewport');
+  await expect(scrollContainer).toBeVisible();
+  await scrollContainer.evaluate(node => {
+    (node as HTMLElement).scrollTop = 0;
   });
+  await expect
+    .poll(async () => {
+      return await scrollContainer.evaluate(node => {
+        return (node as HTMLElement).scrollTop;
+      });
+    })
+    .toBeLessThan(10);
 }
 
 export async function scrollToBottom(page: Page) {
-  // await page.mouse.wheel(0, 1000);
-
-  await page
-    .locator('.affine-page-viewport')
-    .evaluate(node =>
-      node.scrollTo({ left: 0, top: 1000, behavior: 'smooth' })
-    );
-  // TODO switch to `scrollend`
-  // See https://developer.chrome.com/en/blog/scrollend-a-new-javascript-event/
-  await page.waitForFunction(() => {
-    const scrollContainer = document.querySelector('.affine-page-viewport');
-    if (!scrollContainer) {
-      throw new Error("Can't find scroll container");
-    }
-
-    return (
-      // Wait for scrolled to the bottom
-      // Refer to https://stackoverflow.com/questions/3898130/check-if-a-user-has-scrolled-to-the-bottom-not-just-the-window-but-any-element
-      Math.abs(
-        scrollContainer.scrollHeight -
-          scrollContainer.scrollTop -
-          scrollContainer.clientHeight
-      ) < 10
-    );
+  const scrollContainer = page.locator('.affine-page-viewport');
+  await expect(scrollContainer).toBeVisible();
+  await scrollContainer.evaluate(node => {
+    const viewport = node as HTMLElement;
+    viewport.scrollTop = viewport.scrollHeight;
   });
+  await expect
+    .poll(async () => {
+      return await scrollContainer.evaluate(node => {
+        const viewport = node as HTMLElement;
+        return Math.abs(
+          viewport.scrollHeight - viewport.scrollTop - viewport.clientHeight
+        );
+      });
+    })
+    .toBeLessThan(10);
 }
 
 export async function mockParseDocUrlService(