committed 06:10PM - 11 Sep 26 UTC
Previously, the tag-change message pushed to chat providers built its
hashtags w…ith a copy of `PostRevisor.tag_list_to_raw`. That raw is
cooked before being excerpted, so a tag sharing a slug with a category
announced the category to Slack, Teams and Discord.
This change resolves the references through
`HashtagAutocompleteService#hashtags_for` using the acting user's
guardian, which is the same guardian the excerpt is already cooked with.