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/controllers/admin/instances_controller.rb

@@ -49,7 +49,7 @@ module Admin
     private
 
     def set_instance
-      @instance = Instance.find(params[:id])
+      @instance = Instance.find(TagManager.instance.normalize_domain(params[:id]&.strip))
     end
 
     def set_instances