Merge branch 'main' into glitch-soc/merge-upstream

- `.env.production.sample`:
  Our sample config file is very different from upstream since it is much more
  complete. Upstream added documentation for a few env variables.
  Copied the new variables/documentation from upstream.
- `app/lib/feed_manager.rb`:
  Upstream added a timeline type (hashtags), while glitch-soc already had an
  extra one (direct messages). Not really a conflict but textually close
  changes.
  Ported upstream's changes.
- `app/models/custom_emoji.rb`:
  Upstream upped the custom emoji size limit, while glitch-soc had configurable
  limits.
  Upped the default limits accordingly.
- `streaming/index.js`:
  Upstream reworked how hastags were normalized. Minor conflict due to
  glitch-soc's handling of instance-local posts.
  Ported upstream's changes.

app/views/settings/featured_tags/index.html.haml

@@ -9,7 +9,7 @@
   = render 'shared/error_messages', object: @featured_tag
 
   .fields-group
-    = f.input :name, wrapper: :with_block_label, hint: safe_join([t('simple_form.hints.featured_tag.name'), safe_join(@recently_used_tags.map { |tag| link_to("##{tag.name}", settings_featured_tags_path(featured_tag: { name: tag.name }), method: :post) }, ', ')], ' ')
+    = f.input :name, wrapper: :with_block_label, hint: safe_join([t('simple_form.hints.featured_tag.name'), safe_join(@recently_used_tags.map { |tag| link_to("##{tag.display_name}", settings_featured_tags_path(featured_tag: { name: tag.name }), method: :post) }, ', ')], ' ')
 
   .actions
     = f.button :button, t('featured_tags.add_new'), type: :submit