Change routing paths to use usernames in web UI (#16171)

spec/controllers/home_controller_spec.rb

@@ -8,8 +8,10 @@ RSpec.describe HomeController, type: :controller do
 
     context 'when not signed in' do
       context 'when requested path is tag timeline' do
-        before { @request.path = '/web/timelines/tag/name' }
-        it { is_expected.to redirect_to '/tags/name' }
+        it 'redirects to the tag\'s permalink' do
+          @request.path = '/web/timelines/tag/name'
+          is_expected.to redirect_to '/tags/name'
+        end
       end
 
       it 'redirects to about page' do