## Summary
- Fix regression from PR #2336 where `previewCurrentUrlAtom` wasn't
cleared when navigating back to root (`/`)
- Clear preserved URL in `pushState`/`replaceState` handlers when
pathname is "/" or empty
- Clear preserved URL in `restartApp` before restarting to prevent stale
route restoration
- Add E2E test to verify route stays on root after restart

Fixes the issue where HMR/restart would load the wrong URL after
navigating back to root from a sub-route.

## Test plan
- [x] E2E test `restart after navigating back to root should stay on
root` passes
- [x] Existing test `refresh preserves current route` still passes
- [x] Unit tests pass (661 tests)

🤖 Generated with [Claude Code](https://claude.com/claude-code)
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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Medium risk because it changes preview navigation state persistence
and restart behavior, which could impact route restoration and
back/forward history across apps. Added e2e coverage reduces the chance
of regressions.
> 
> **Overview**
> Fixes a regression where the preview could restore a stale sub-route
after returning to `/` or after an app restart.
> 
> `PreviewIframe` now **clears `previewCurrentUrlAtom`** when
`pushState`/`replaceState` navigates to same-origin root, and
`useRunApp.restartApp` clears the preserved URL for the app before
restarting to avoid remount restoring the wrong route.
> 
> Adds an e2e Playwright test ensuring navigating `/about` → `/` and
then restarting stays on the home route.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
16db90a34c728f311599eab4c029010d89354420. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

<!-- This is an auto-generated description by cubic. -->
---
## Summary by cubic
Fixes a regression where the preview restored a stale sub-route after
returning to “/” or restarting. We now clear the preserved URL so the
app stays on the expected root route.

- **Bug Fixes**
- Clear preserved URL on pushState/replaceState when pathname is “/” in
PreviewIframe.
- Clear preserved URL during restart (useRunApp) to prevent stale route
restoration.
  - Add E2E test to ensure restart after returning to root stays on “/”.

- **New Features**
- Allow disabling the stop hook via DISABLE_DYAD_STOP_HOOK environment
variable.

<sup>Written for commit 16db90a34c728f311599eab4c029010d89354420.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>