fix(ci): upload Playwright reports from the correct frontend directory (#6859)

# Description of Changes

This change fixes the artifact upload path used by the Playwright E2E
workflows after the frontend directory structure was updated.

### What was changed

- Updated the Playwright report artifact path from:
  - `frontend/editor/playwright-report/`
  - to `frontend/playwright-report/`
- Applied the fix to:
  - `build-enterprise.yml`
  - `e2e-stubbed.yml`
  - `nightly.yml`
- Renamed the nightly Playwright artifact from:
  - `playwright-nightly-${{ github.run_id }}`
  - to `playwright-report-nightly-${{ github.run_id }}`
  for consistency with the other workflows.

### Why the change was made

The workflows attempted to upload artifacts from a directory that no
longer exists, causing GitHub Actions to report:

> No files were found with the provided path:
`frontend/editor/playwright-report/`

Updating the upload path ensures Playwright reports are successfully
collected and available for debugging failed E2E runs.

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have run `task check` to verify linters, typechecks, and tests
pass
- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#7-testing)
for more details.

.github/workflows/build-enterprise.yml

@@ -285,5 +285,5 @@ jobs:
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
           name: playwright-report-enterprise-${{ github.run_id }}
-          path: frontend/editor/playwright-report/
+          path: frontend/playwright-report/
           retention-days: 7