Editing a message with a mention/ping in it malforms the mention/ping

[bunlibnow]

Describe the bug

When you edit a message that has a mention of someone in it, then Sable mangles the mention/ping.

Original message:

Edit open:

After editing:

Reproduction

1. Send a message with a mention/ping
2. Edit it

Expected behavior

Editing would leave the mention/ping alone.

Platform and versions

1. Linux
2. Firefox 140.10.2esr
3. 1.16.1

Additional context

No response