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

Conflicts:
- `README.md`:
  Upstream updated its README, while we have a completely different one.
  Kept our README.
- `app/controllers/concerns/web_app_controller_concern.rb`:
  Conflict because of glitch-soc's theming system.
  Additionally, glitch-soc has different behavior regarding moved accounts.
  Ported some of the changes, but kept our overall behavior.
- `app/javascript/packs/admin.js`:
  Code changes actually applied to `app/javascript/core/admin.js`

app/validators/url_validator.rb

@@ -10,5 +10,7 @@ class URLValidator < ActiveModel::EachValidator
   def compliant?(url)
     parsed_url = Addressable::URI.parse(url)
     parsed_url && %w(http https).include?(parsed_url.scheme) && parsed_url.host
+  rescue Addressable::URI::InvalidURIError
+    false
   end
 end