Anchor links to same page in Collectives broken in edit mode

[mejo-]

Describe the bug
Anchor links to the same page work in Collectives in view mode, but in edit mode the link bubble opens and then clicking the bubble doesn't do anything.

Server details:

• Nextcloud version: 33.06

[hiSandog]

A useful next step would be to turn this into a small editor-mode regression test: create a Collectives page with an anchor link pointing to a heading on the same page, enter edit mode, and assert that following the link keeps the route and scroll target consistent. That should clarify whether the breakage is in markdown link rewriting, router handling, or the edit-mode preview layer.