hashtag "#books" links to 3rd party domain

[fabiscafe]

Describe the bug
Recently I wrote a comment on bookwyrm.social. While I was testing the hashtags, because of #2742 , I noticed that one of my hashtag "#books" links to https://the.talesofmy.life/search?tag=books

To Reproduce
Steps to reproduce the behavior:

1. Go to Bookywyrm.social
2. Post a comment with the hashtag "#books"
3. Open that comment and click on #books

Expected behavior
It should just open other posts marked as #books

Instance
bookwyrm.social and since the link is embedded in the hashtag it's everywhere

Additional context
This seems to be a general problem with hashtags on bookwyrm, that they are hardcoded to one instance instead of flexible to resolve the hashtag on whatever instance the viewer clicks on them.

Comment with this problem: https://bookwyrm.social/user/fabiscafe/comment/4009858

---

Desktop (please complete the following information):
- OS: Arch Linux
- Browser: Firefox
- Version: 123

[Minnozz]

I think this code may be relevant:

bookwyrm/bookwyrm/activitypub/note.py

Lines 61 to 72 in 9e7b040

	# Replace links to hashtags in content with local URLs
	changed_content = False
	for hashtag in instance.mention_hashtags.all():
	updated_content = re.sub(
	rf'(<a href=")[^"]*(" data-mention="hashtag">{hashtag.name}</a>)',
	rf"\1{hashtag.remote_id}\2",
	instance.content,
	flags=re.IGNORECASE,
	)
	if instance.content != updated_content:
	instance.content = updated_content
	changed_content = True

[gsergey418]

Everything seems to work fine on my test instace, looks like a bookwyrm.social problem

[fabiscafe]

So it might be that #books does have a broken entry in the database and bookwyrm looks it up without recheck if the url fits?
Something that cant be recreated with new instances, because it doesn't happen for newly added hashtags.