ヘルプを Wiki から分離 (#424) (#430)

画面上でのテストは完了．
移行にす早さが求められるので，準備ができたらマージする．

Reviewed-on: #430
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/spec/requests/wiki_conflict_spec.rb

@@ -1,6 +1,7 @@
 require 'rails_helper'
 
 RSpec.describe 'Wiki conflict handling', type: :request do
+  include WikiRecords
   let!(:user) { create_member_user! }
 
   def auth_headers user
@@ -9,8 +10,8 @@ RSpec.describe 'Wiki conflict handling', type: :request do
 
   it 'returns 409 when base_revision_id is stale' do
     page =
-        Wiki::Commit.create_content!(
-            tag_name: create(:tag_name, name: 'wiki_conflict_request'),
+        seed_wiki_page(
+            tag_name: create(:tag, primary_name: 'wiki_conflict_request').tag_name('ja'),
             body: 'first',
             created_by_user: user,
             message: 'init')
@@ -25,12 +26,10 @@ RSpec.describe 'Wiki conflict handling', type: :request do
         base_revision_id: stale_id)
 
     put "/wiki/#{ page.id }",
-        params: {
-          title: 'wiki_conflict_request',
-          body: 'third',
-          message: 'stale',
-          base_revision_id: stale_id,
-        },
+        params: { title: 'wiki_conflict_request',
+                  body: 'third',
+                  message: 'stale',
+                  base_revision_id: stale_id },
         headers: auth_headers(user)
 
     expect(response).to have_http_status(:conflict)