Merge branch '4.x' into 5.x

fix: Hide resize handles on disabled rich editor (#19718)

Merge branch '4.x' into 5.x

fix: fix rich editor file attachment test temporary uploads (#19697)

Merge branch '4.x' into 5.x

feature: Grouped custom rich editor blocks (#19653)

* feature: Grouped custom rich editor blocks

* screenshot

* Update RichContentAttribute.php

Merge branch '4.x' into 5.x

chore(deps): bump vite from 6.4.1 to 6.4.2 in /docs-assets/app (#19645)

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 6.4.1 to 6.4.2.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/v6.4.2/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v6.4.2/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-version: 6.4.2
  dependency-type: direct:production
...

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fix: preserve sidebar scroll position across navigation (#19632)

Merge branch '4.x' into 5.x