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/paragraph.spec.ts

@@ -31,6 +31,7 @@ import {
   redoByClick,
   redoByKeyboard,
   resetHistory,
+  setInlineRangeInInlineEditor,
   setSelection,
   SHORT_KEY,
   switchReadonly,
@@ -87,10 +88,9 @@ test('init paragraph by page title enter in middle', async ({ page }) => {
   await waitDefaultPageLoaded(page);
   await focusTitle(page);
   await type(page, 'hello');
-  await page.keyboard.press('ArrowLeft');
-  await page.keyboard.press('ArrowLeft');
-  await page.keyboard.press('ArrowLeft');
+  await setInlineRangeInInlineEditor(page, { index: 2, length: 0 });
   await pressEnter(page);
+  await waitNextFrame(page, 200);
 
   await assertTitle(page, 'he');
   await assertRichTexts(page, ['llo', '']);