## Summary
Adds a Playwright E2E test suite covering the dashboard Favorites
feature — favoriting/unfavoriting a dashboard, the `Favorites`
pseudo-folder view, and its interaction with single and bulk delete
flows.
## What's covered
New `dashboard-favorites.spec.js` (6 tests) + `DashboardFavorites` page
object:
- Add a dashboard to favorites and verify it appears in the Favorites
view
- Remove a dashboard from favorites — confirms it drops from the
Favorites view while the dashboard itself remains untouched
- Favorite state persists across a page reload
- Bulk-delete a favorited dashboard from the Favorites view completes
successfully with no error
- Deleting a dashboard directly also removes it from Favorites
automatically
- Bulk-deleting a dashboard from the Favorites view doesn't leave a
stale copy behind in its original folder
## CI
`dashboard-favorites.spec.js` runs in its own dedicated
`Dashboards-Isolated` shard with a fresh backend instance, keeping it
independent from the rest of the dashboard test suite.