WIP: preserve Issue #479 changes

Refs #454

## Automated implementation (requires human review)
[SidebarComponent.tsx](frontend/src/components/layout/SidebarComponent.tsx) の1行を修正しました。`overflow-y-auto` を `md` 以上に限定し、スマホでサゼストがサイドバーの領域外で切られる原因を取り除きました。

差分を確認済みです。指定に従い、テスト・lint・ビルドは未実行です。実画面でのスマホ表示とPC表示の確認も未実施です。

## Automated review (not a guarantee of correctness)
```text
The change restricts sidebar scrolling to medium and larger viewports. No actionable regression was identified in the current diff.

```

## Verification
- Tests/builds/migrations were not authorized and were not invoked by the controller.
- Codex was instructed not to run them; its command transcript should be inspected.
- Do not merge before manual acceptance and required checks.

---------

Co-authored-by: Codex Night Worker <codex-night@localhost>
Reviewed-on: #456
Co-authored-by: テツノニジカ <969+codex-bot@noreply.localhost>

backend/AGENTS.md

@@ -424,7 +424,7 @@ races according to the target constraint's business meaning.
   and JSON keys are generally snake_case.
 - Preserve existing HTTP status conventions:
   `:unauthorized` for no user, `:forbidden` for insufficient role or banned
-  user, `:not_found` for missing records, and `:unprocessable_entity` for
+  user, `:not_found` for missing records, and `:unprocessable_content` for
   validation failures.
 - For diagnostic or internal helper JSON, prefer a deliberately light response
   shape over full representation classes when callers only need identifiers,

backend/app/controllers/application_controller.rb

@@ -95,7 +95,7 @@ class ApplicationController < ActionController::API
     render_validation_error base: ['すでに存在してゐます．']
   end
 
-  def render_validation_error record = nil, fields: { }, base: [], status: :unprocessable_entity
+  def render_validation_error record = nil, fields: { }, base: [], status: :unprocessable_content
     errors = { }
 
     if record

backend/app/controllers/counts_exports_controller.rb

@@ -18,7 +18,7 @@ class CountsExportsController < ApplicationController
     render json: { error: 'private_condition' }, status: :forbidden
   rescue CountsTableQuery::TooManyColumns
     render json: { error: 'too_many_columns', max_columns: CountsTableQuery::MAX_COLUMNS },
-           status: :unprocessable_entity
+           status: :unprocessable_content
   rescue ActiveRecord::StatementTimeout
     render json: { error: 'counts_query_timeout' }, status: :service_unavailable
   rescue ArgumentError, TypeError, KeyError, JSON::ParserError
@@ -63,7 +63,7 @@ class CountsExportsController < ApplicationController
     render json: { error: 'private_condition' }, status: :forbidden
   rescue CountsTableQuery::TooManyColumns
     render json: { error: 'too_many_columns', max_columns: CountsTableQuery::MAX_COLUMNS },
-        status: :unprocessable_entity
+        status: :unprocessable_content
   rescue ActiveRecord::StatementTimeout
     render json: { error: 'counts_query_timeout' }, status: :service_unavailable
   rescue ArgumentError, TypeError, KeyError, JSON::ParserError
@@ -107,7 +107,7 @@ class CountsExportsController < ApplicationController
     render json: { error: 'private_condition' }, status: :forbidden
   rescue CountsTableQuery::TooManyColumns
     render json: { error: 'too_many_columns', max_columns: CountsTableQuery::MAX_COLUMNS },
-        status: :unprocessable_entity
+        status: :unprocessable_content
   rescue ActiveRecord::StatementTimeout
     render json: { error: 'counts_query_timeout' }, status: :service_unavailable
   rescue ArgumentError, TypeError, KeyError, JSON::ParserError

backend/app/controllers/counts_tables_controller.rb

@@ -24,7 +24,7 @@ class CountsTablesController < ApplicationController
     render json: { error: 'private_condition' }, status: :forbidden
   rescue CountsTableQuery::TooManyColumns
     render json: { error: 'too_many_columns', max_columns: CountsTableQuery::MAX_COLUMNS },
-           status: :unprocessable_entity
+           status: :unprocessable_content
   rescue CountsPivotTotals::TimedOut
     Rails.logger.warn('counts_query_timeout: pivot_totals')
     render json: { error: 'counts_query_timeout', stage: 'totals',

backend/app/controllers/gekanator_games_controller.rb

@@ -15,7 +15,7 @@ class GekanatorGamesController < ApplicationController
         answers:)
 
     if game.invalid?
-      render json: { errors: game.errors.full_messages }, status: :unprocessable_entity
+      render json: { errors: game.errors.full_messages }, status: :unprocessable_content
       return
     end
 
@@ -31,7 +31,7 @@ class GekanatorGamesController < ApplicationController
       learned_example_count:
     }, status: :created
   rescue ActiveRecord::RecordInvalid => e
-    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
+    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_content
   end
 
   def extra_questions

backend/app/controllers/materials_controller.rb

@@ -536,7 +536,7 @@ class MaterialsController < ApplicationController
                    errors: { },
                    base_errors: ['ZIP export に必要な素材ファイルが欠損しています．'],
                    missing_files: },
-           status: :unprocessable_entity
+           status: :unprocessable_content
   end
 
   def build_uploaded_material_blob! file, file_sha256

backend/app/controllers/posts_controller.rb

@@ -429,7 +429,7 @@ class PostsController < ApplicationController
     filters = literals.map do |literal|
       internal, = source_ids.fetch(literal[:name])
       name = internal.empty? ? literal[:name] : names[internal.first]
-      return head :unprocessable_entity unless name && internal.length <= 1
+      return head :unprocessable_content unless name && internal.length <= 1
 
       literal[:negative] ? "not:#{ name }" : name
     end
@@ -438,7 +438,7 @@ class PostsController < ApplicationController
     literals.zip(translated).each do |literal, translation|
       unless (source_ids.fetch(literal[:name]).map(&:sort) ==
           target_ids.fetch(translation[:name]).map(&:sort))
-        return head :unprocessable_entity
+        return head :unprocessable_content
       end
     end
     index = 0

backend/app/controllers/theatres_controller.rb

@@ -55,7 +55,7 @@ class TheatresController < ApplicationController
     theatre = Theatre.find_by(id: params[:id])
     return head :not_found unless theatre
     requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
+    return head :unprocessable_content if requested_post_id <= 0
 
     skipped = false
     conflicted = false
@@ -95,7 +95,7 @@ class TheatresController < ApplicationController
     theatre = Theatre.find_by(id: params[:id])
     return head :not_found unless theatre
     requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
+    return head :unprocessable_content if requested_post_id <= 0
 
     conflicted = false
 

backend/spec/requests/counts_table_spec.rb

@@ -262,7 +262,7 @@ RSpec.describe 'Counts table API', type: :request do
           tags: '', tags_json: [], parent_post_ids: '', created_at: Time.utc(2024, 3))
     end
     get '/counts/query', params: base.merge(mode: 'summary', rows: '', cols: 'title', sort: '')
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(response.parsed_body).to eq('error' => 'too_many_columns', 'max_columns' => 100)
   end
 

backend/spec/requests/error_responses_spec.rb

@@ -20,7 +20,7 @@ RSpec.describe 'error responses', type: :request do
 
       patch "/tags/#{ tag.id }", params: { category: 'nico' }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include(
           'type' => 'validation_error',
           'message' => '入力内容を確認してください．',
@@ -37,7 +37,7 @@ RSpec.describe 'error responses', type: :request do
 
       put "/users/#{ user.id }", params: { name: 'a' * 256 }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include(
           'type' => 'validation_error',
           'message' => '入力内容を確認してください．')

backend/spec/requests/gekanator_games_spec.rb

@@ -49,7 +49,7 @@ RSpec.describe 'Gekanator games API', type: :request do
           question_count: 4,
           answers: [{ question_id: 'tag:1', answer: 'no' }] }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'returns unauthorized without a user' do

backend/spec/requests/gekanator_learning_spec.rb

@@ -126,7 +126,7 @@ RSpec.describe 'Gekanator learning API', type: :request do
         }
       }.not_to change { GekanatorGame.count }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'stores a game result for a non-admin user' do
@@ -785,7 +785,7 @@ RSpec.describe 'Gekanator learning API', type: :request do
         }
       }.not_to change { GekanatorQuestionExample.count }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'rejects non-accepted questions' do
@@ -805,7 +805,7 @@ RSpec.describe 'Gekanator learning API', type: :request do
         ]
       }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'rejects non-post_similarity questions' do
@@ -829,7 +829,7 @@ RSpec.describe 'Gekanator learning API', type: :request do
         ]
       }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'allows a non-admin user to answer extra questions for their own game' do

backend/spec/requests/locale_write_paths_spec.rb

@@ -55,7 +55,7 @@ RSpec.describe 'Locale propagation on write paths', type: :request do
         deprecated: false, aliases: 'other_primary', parent_tags: '' }
 
     aggregate_failures do
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(other_primary.reload).to have_attributes(tag_id: other_tag.id, primary_flg: true)
       expect(TagName.where(tag: other_tag, language_code: 'ja', primary_flg: true))
           .to contain_exactly(other_primary)
@@ -289,7 +289,7 @@ RSpec.describe 'Locale propagation on write paths', type: :request do
           aliases: 'other_ainu_primary', parent_tags: '' }
 
       aggregate_failures do
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(other_primary.reload).to have_attributes(
             tag_id: other_tag.id, language_code: 'ain', primary_flg: true)
         expect(TagName.where(tag: other_tag, language_code: 'ain', primary_flg: true))

backend/spec/requests/materials_spec.rb

@@ -289,7 +289,7 @@ RSpec.describe 'Materials API', type: :request do
       it 'returns 422 when tag is blank' do
         post '/materials', params: { tag: '   ', file: dummy_upload }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
             'tag' => ['タグは必須です．'])
       end
@@ -297,7 +297,7 @@ RSpec.describe 'Materials API', type: :request do
       it 'returns 422 when both file and url are blank' do
         post '/materials', params: { tag: 'material_create_blank' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
             'file' => ['ファイルまたは URL は必須です．'],
             'url' => ['ファイルまたは URL は必須です．'])
@@ -381,7 +381,7 @@ RSpec.describe 'Materials API', type: :request do
           file: dummy_upload
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
 
       it 'persists url-only material' do
@@ -424,7 +424,7 @@ RSpec.describe 'Materials API', type: :request do
           }
         end.not_to change(Material, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
           'file' => ['抑止された素材です: copyright_high_risk']
         )
@@ -484,7 +484,7 @@ RSpec.describe 'Materials API', type: :request do
           file: dummy_upload
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
             'tag' => ['タグは必須です．'])
       end
@@ -695,7 +695,7 @@ RSpec.describe 'Materials API', type: :request do
           file: dummy_upload(filename: 'blocked.png', body: 'blocked-update')
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(material.reload.file.blob.filename.to_s).to eq('old.png')
       end
     end

backend/spec/requests/nico_tags_spec.rb

@@ -218,7 +218,7 @@ RSpec.describe 'NicoTags', type: :request do
 
       patch "/tags/nico/#{nico_tag.id}", params: { tags: 'nico:linked_ng' }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
           'tags' => ['ニコニコ・タグ同士は連携できません．'])
     end
@@ -239,7 +239,7 @@ RSpec.describe 'NicoTags', type: :request do
 
       expect([Tag.count, TagName.count, TagVersion.count]).to eq(before_counts)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors').fetch('tags')).to include(
           a_string_including('タグ名 “invalid”:', '名前に使用できない文字が含まれてゐます．'))
     end

backend/spec/requests/post_locale_filter_identity_spec.rb

@@ -48,7 +48,7 @@ RSpec.describe 'Post filter identity across locales', type: :request do
     primary_tag_name_for(tag, 'ja').update_columns(name: 'nico:shared')
     get '/posts/tag_filters', params: {
         locale: 'ja', target_locale: 'ain-Kana', tags: 'nico:shared' }
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
   end
 
   it 'rejects removed reference parameters instead of overriding the name' do

backend/spec/requests/posts_spec.rb

@@ -1042,7 +1042,7 @@ RSpec.describe 'Posts API', type: :request do
 
       get '/posts/metadata', params: { url: 'file:///etc/passwd' }
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to have_key('url')
     end
   end
@@ -1180,7 +1180,7 @@ RSpec.describe 'Posts API', type: :request do
         )
       }.not_to change(Post, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'thumbnail' => ['サムネイル画像の変換に失敗しました．']
       )
@@ -1219,7 +1219,7 @@ RSpec.describe 'Posts API', type: :request do
         thumbnail: dummy_upload
       )
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'tags' => ['廃止済みタグがあります: deprecated_direct_tag']
       )
@@ -1265,7 +1265,7 @@ RSpec.describe 'Posts API', type: :request do
         thumbnail: dummy_upload
       )
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include(
         'type' => 'validation_error',
         'message' => '入力内容を確認してください．'
@@ -1333,7 +1333,7 @@ RSpec.describe 'Posts API', type: :request do
         thumbnail: dummy_upload
       )
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'video_ms' => ['タグ区間の終端が動画時間を超えてゐます．']
       )
@@ -1444,7 +1444,7 @@ RSpec.describe 'Posts API', type: :request do
         thumbnail: dummy_upload
       )
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'video_ms' => ['タグ区間の開始が動画時間以上です．']
       )
@@ -1465,7 +1465,7 @@ RSpec.describe 'Posts API', type: :request do
           thumbnail: dummy_upload
         )
 
-        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(response).to have_http_status(:unprocessable_content), response.body
         expect(json).to include(
             'type' => 'validation_error',
             'message' => '入力内容を確認してください．',
@@ -1485,7 +1485,7 @@ RSpec.describe 'Posts API', type: :request do
             tags: 'spec_tag', # 既存タグ名を投げる
             thumbnail: dummy_upload)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
     end
 
@@ -1499,7 +1499,7 @@ RSpec.describe 'Posts API', type: :request do
             tags: 'spec_tag', # 既存タグ名を投げる
             thumbnail: dummy_upload)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
     end
 
@@ -1601,7 +1601,7 @@ RSpec.describe 'Posts API', type: :request do
               thumbnail: dummy_upload }
         }.not_to change(Post, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to be_present
       end
     end
@@ -1620,7 +1620,7 @@ RSpec.describe 'Posts API', type: :request do
           )
         }.not_to change(Post, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to be_present
       end
     end
@@ -1639,7 +1639,7 @@ RSpec.describe 'Posts API', type: :request do
           )
         }.not_to change(PostImplication, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to be_present
       end
     end
@@ -1770,7 +1770,7 @@ RSpec.describe 'Posts API', type: :request do
         tags: 'deprecated_update_tag'
       )
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'tags' => ['廃止済みタグは付与できません．']
       )
@@ -1789,7 +1789,7 @@ RSpec.describe 'Posts API', type: :request do
             title: 'updated title',
             tags: 'nico:nico_tag')
 
-        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(response).to have_http_status(:unprocessable_content), response.body
         expect(json).to include(
             'type' => 'validation_error',
             'message' => '入力内容を確認してください．',
@@ -1896,7 +1896,7 @@ RSpec.describe 'Posts API', type: :request do
             title: 'updated title',
             tags: 'spec_tag' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to be_present
       end
     end
@@ -1922,7 +1922,7 @@ RSpec.describe 'Posts API', type: :request do
           parent_post_ids: 'abc'
         )
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(post_record.reload.parent_posts.pluck(:id)).to eq([parent_post.id])
       end
     end
@@ -1948,7 +1948,7 @@ RSpec.describe 'Posts API', type: :request do
           parent_post_ids: '999999999'
         )
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(post_record.reload.parent_posts.pluck(:id)).to eq([parent_post.id])
       end
     end
@@ -1964,7 +1964,7 @@ RSpec.describe 'Posts API', type: :request do
           parent_post_ids: post_record.id.to_s
         )
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
 
         expect(PostImplication.exists?(
           post_id: post_record.id,
@@ -2669,7 +2669,7 @@ RSpec.describe 'Posts API', type: :request do
             thumbnail: dummy_upload)
       end.not_to change(PostVersion, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'does not create a version when PUT /posts/:id is invalid' do
@@ -2685,7 +2685,7 @@ RSpec.describe 'Posts API', type: :request do
             original_created_before: Time.zone.local(2020, 1, 1, 0, 0, 0).iso8601)
       end.not_to change(PostVersion, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'rejects second-bearing original created timestamps on POST /posts' do
@@ -2698,7 +2698,7 @@ RSpec.describe 'Posts API', type: :request do
           thumbnail: dummy_upload,
           original_created_from: '2020-01-01T00:00:01Z')
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'original_created_from' => ['オリジナルの作成日時は分単位で入力してください．']
       )
@@ -2715,7 +2715,7 @@ RSpec.describe 'Posts API', type: :request do
           thumbnail: dummy_upload,
           original_created_before: '2020-01-01T00:00:00.123Z')
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'original_created_before' => ['オリジナルの作成日時は分単位で入力してください．']
       )
@@ -2733,7 +2733,7 @@ RSpec.describe 'Posts API', type: :request do
           original_created_from: '2020-01-01T00:00Z',
           original_created_before: '2020-01-01T00:00Z')
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'original_created_at' => ['オリジナルの作成日時の順番がをかしぃです．']
       )
@@ -2767,7 +2767,7 @@ RSpec.describe 'Posts API', type: :request do
           tags: 'spec_tag',
           original_created_from: 'not-a-time')
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
         'original_created_from' => ['オリジナルの作成日時の形式が不正です．']
       )

backend/spec/requests/tag_children_spec.rb

@@ -64,7 +64,7 @@ RSpec.describe "TagChildren", type: :request do
           do_request
         }.not_to change(TagImplication, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(TagImplication.where(tag: child, parent_tag: parent)).not_to exist
       end
     end

backend/spec/requests/tag_descriptions_spec.rb

@@ -303,7 +303,7 @@ RSpec.describe 'Tag description native API', type: :request do
       headers
       before_state = stored_state
       native_write(body: '')
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include('type' => 'validation_error',
                              'errors' => include('body' => a_kind_of(Array)))
       expect(stored_state).to eq(before_state)

backend/spec/requests/tag_group_locale_spec.rb

@@ -84,7 +84,7 @@ RSpec.describe 'Tag group locale contracts', type: :request do
     put "/wiki/#{ group.id }", params: {
         locale: 'ain-Kana', title: 'タググループ:partial rename', body: '- japanese_member' },
         headers: headers
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(group_state).to eq(before_state)
   end
 
@@ -117,7 +117,7 @@ RSpec.describe 'Tag group locale contracts', type: :request do
     expect(representation.fetch('members').sole.fetch('tag').fetch('name')).to be_nil
     expect(representation.fetch('placements').sole.fetch('tag').fetch('name')).to be_nil
     get "/wiki/#{ old_group.id }", params: { locale: 'ain-Kana', version: version.id }
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(response.body).not_to include('historical_japanese', 'current_ainu')
   end
 end

backend/spec/requests/tag_group_markdown_spec.rb

@@ -133,7 +133,7 @@ RSpec.describe 'Tag group Markdown round trips through the Wiki facade', type: :
 
     get group_title_path('混在構造')
 
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(group_rows('tag_groups', id:).sole.fetch('id')).to eq(id)
   end
 
@@ -142,7 +142,7 @@ RSpec.describe 'Tag group Markdown round trips through the Wiki facade', type: :
 
     get group_title_path('未配置構造')
 
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(group_rows('tag_groups', id:).sole.fetch('id')).to eq(id)
   end
 end

backend/spec/requests/tag_group_wiki_write_spec.rb

@@ -21,7 +21,7 @@ RSpec.describe 'Tag group Wiki facade writes', type: :request do
     before_state = group_state
     yield
     aggregate_failures do
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(group_state).to eq(before_state)
       expect(response.media_type).to eq('application/json')
       expect(response.body).not_to be_empty

backend/spec/requests/tag_group_write_integrity_spec.rb

@@ -27,7 +27,7 @@ RSpec.describe 'Tag group write integrity', type: :request do
   def expect_no_writes
     before_state = group_state
     yield
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
     expect(group_state).to eq(before_state)
   end
 

backend/spec/requests/tag_groups_spec.rb

@@ -148,7 +148,7 @@ RSpec.describe 'Tag group native API', type: :request do
           before_state = group_state
           native_write(operation, payload.merge(invalid))
           aggregate_failures do
-            expect(response).to have_http_status(:unprocessable_entity)
+            expect(response).to have_http_status(:unprocessable_content)
             expect(group_state).to eq(before_state)
           end
         end
@@ -158,7 +158,7 @@ RSpec.describe 'Tag group native API', type: :request do
         before_state = group_state
         invalid = [{ tag_id: tag.id, section_name: '不正', children: [] }]
         native_write(operation, payload.merge(placements: invalid))
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(group_state).to eq(before_state)
       end
 
@@ -167,7 +167,7 @@ RSpec.describe 'Tag group native API', type: :request do
         before_state = group_state
         native_write(operation, payload.merge(
             members: [{ tag_id: missing }], placements: [{ tag_id: missing, children: [] }]))
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(group_state).to eq(before_state)
       end
 
@@ -177,7 +177,7 @@ RSpec.describe 'Tag group native API', type: :request do
         native_write(operation, payload.merge(
             members: [{ tag_group_id: missing }],
             placements: [{ tag_group_id: missing, children: [] }]))
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(group_state).to eq(before_state)
       end
 
@@ -186,7 +186,7 @@ RSpec.describe 'Tag group native API', type: :request do
         6.times { nodes = [{ tag_id: tag.id, children: nodes }] }
         before_state = group_state
         native_write(operation, payload.merge(placements: nodes))
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(group_state).to eq(before_state)
       end
     end
@@ -206,7 +206,7 @@ RSpec.describe 'Tag group native API', type: :request do
       before_state = group_state
       native_write(:update, payload.merge(
           members: [{ tag_group_id: parent }], placements: []))
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(group_state).to eq(before_state)
     end
 
@@ -214,7 +214,7 @@ RSpec.describe 'Tag group native API', type: :request do
       before_state = group_state
       native_write(:update, payload.merge(
           members: [{ tag_group_id: group_id }], placements: []))
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(group_state).to eq(before_state)
     end
 

backend/spec/requests/tags_deerjikists_spec.rb

@@ -297,7 +297,7 @@ RSpec.describe 'Tags deerjikists API', type: :request do
             do_request
           }.not_to change { Deerjikist.where(tag: tag).map { |d| [d.platform, d.code] } }
 
-          expect(response).to have_http_status(:unprocessable_entity)
+          expect(response).to have_http_status(:unprocessable_content)
           expect(json).to include(
               'type' => 'validation_error',
               'message' => '入力内容を確認してください．',
@@ -321,7 +321,7 @@ RSpec.describe 'Tags deerjikists API', type: :request do
             do_request
           }.not_to change { Deerjikist.where(tag: tag).map { |d| [d.platform, d.code] } }
 
-          expect(response).to have_http_status(:unprocessable_entity)
+          expect(response).to have_http_status(:unprocessable_content)
           expect(json.fetch('errors')).to include(
             'deerjikists.0.platform' => [be_present],
           )
@@ -352,7 +352,7 @@ RSpec.describe 'Tags deerjikists API', type: :request do
             do_request
           }.not_to change { Deerjikist.order(:platform, :code).pluck(:platform, :code, :tag_id) }
 
-          expect(response).to have_http_status(:unprocessable_entity)
+          expect(response).to have_http_status(:unprocessable_content)
           expect(json.fetch('errors')).to include(
             'deerjikists.1.code' => [include('existing-deerjikist')],
           )

backend/spec/requests/tags_spec.rb

@@ -696,7 +696,7 @@ RSpec.describe 'Tags API', type: :request do
       it 'nico category への変更は 422 を返す' do
         patch "/tags/#{tag.id}", params: { name: 'new', category: 'nico' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(primary_tag_name_for(tag.reload, 'ja').name).to eq('spec_tag')
         expect(tag.category).to eq('general')
       end
@@ -740,7 +740,7 @@ RSpec.describe 'Tags API', type: :request do
           patch "/tags/#{tag.id}", params: { category: 'nico' }
         }.not_to change(TagVersion, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(tag.reload.category).to eq('general')
       end
 
@@ -824,7 +824,7 @@ RSpec.describe 'Tags API', type: :request do
 
         patch "/tags/#{ tag.id }", params: { name: 'unknown' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
           'name' => ['その名前は既に使はれてゐます．']
         )
@@ -840,7 +840,7 @@ RSpec.describe 'Tags API', type: :request do
 
         patch "/tags/#{ system_tag.id }", params: { name: 'patch_system_tag_renamed' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(primary_tag_name_for(system_tag.reload, 'ja').name).to eq('bot操作')
       end
     end
@@ -1144,7 +1144,7 @@ RSpec.describe 'Tags API', type: :request do
           parent_tags: '',
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(primary_tag_name_for(tag.reload, 'ja').name).to eq('spec_tag')
       end
 
@@ -1156,7 +1156,7 @@ RSpec.describe 'Tags API', type: :request do
           parent_tags: '',
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(primary_tag_name_for(tag.reload, 'ja').name).to eq('spec_tag')
         expect(tag.category).to eq('general')
       end
@@ -1169,7 +1169,7 @@ RSpec.describe 'Tags API', type: :request do
           parent_tags: '',
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(json.fetch('errors')).to include(
           'deprecated' => ['廃止状態は必須です．']
         )
@@ -1366,7 +1366,7 @@ RSpec.describe 'Tags API', type: :request do
           }
         }.not_to change(TagVersion, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
 
         expect(primary_tag_name_for(tag.reload, 'ja').name).to eq('spec_tag')
         expect(tag.category).to eq('general')
@@ -1387,7 +1387,7 @@ RSpec.describe 'Tags API', type: :request do
           }
         }.not_to change(TagVersion, :count)
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
 
         expect(primary_tag_name_for(system_tag.reload, 'ja').name).to eq(old_name)
         expect(system_tag.category).to eq(old_category)
@@ -1569,7 +1569,7 @@ RSpec.describe 'Tags API', type: :request do
           deprecated: '0',
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
 
         expect(TagImplication.where(tag:, parent_tag: child)).not_to exist
       end

backend/spec/requests/theatre_comments_spec.rb

@@ -131,7 +131,7 @@ RSpec.describe 'TheatreComments', type: :request do
         post "/theatres/#{theatre.id}/comments", params: { content: '   ' }
       }.not_to change(TheatreComment, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'theatre が存在しなければ 404 を返す' do

backend/spec/requests/theatres_spec.rb

@@ -376,7 +376,7 @@ RSpec.describe 'Theatres API', type: :request do
         put "/theatres/#{theatre.id}/skip_vote", params: { post_id: 'invalid' }
       }.not_to change(TheatreSkipVote, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
     end
 
     it 'records a vote and returns the current vote status before majority' do

backend/spec/requests/user_settings_spec.rb

@@ -79,7 +79,7 @@ RSpec.describe 'user settings', type: :request do
 
       patch '/users/settings', params: { theme: 1 }, as: :json
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include('type' => 'validation_error')
       expect(json.fetch('errors')).to include(
           'theme' => ['値の型が不正です．'])
@@ -90,7 +90,7 @@ RSpec.describe 'user settings', type: :request do
 
       patch '/users/settings', params: { theme: 'neon' }, as: :json
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json).to include('type' => 'validation_error')
       expect(json.fetch('errors').fetch('theme')).to be_present
     end

backend/spec/requests/user_theme_slots_spec.rb

@@ -84,7 +84,7 @@ RSpec.describe 'user theme slots', type: :request do
           params: { tokens: 'not-object' },
           as: :json
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
           'base_theme' => ['値が不正です．'])
     end
@@ -96,7 +96,7 @@ RSpec.describe 'user theme slots', type: :request do
           params: { tokens: 'not-object' },
           as: :json
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
           'tokens' => ['JSON object で指定してください．'])
     end

backend/spec/requests/users_spec.rb

@@ -119,7 +119,7 @@ RSpec.describe 'Users', type: :request do
           params: { name: '   ' },
           headers: auth_headers(user)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(json.fetch('errors')).to include(
           'name' => ['名前は必須です．'])
     end

backend/spec/requests/wiki_creation_freeze_spec.rb

@@ -39,7 +39,7 @@ RSpec.describe 'Wiki creation freeze', type: :request do
       it "rejects invalid description body #{ body.inspect } atomically" do
         before_state = group_state
         put "/wiki/#{ page.id }", params: { title: tag.name('ja'), body: }, headers: headers
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
         expect(group_state).to eq(before_state)
       end
     end

backend/spec/requests/wiki_spec.rb

@@ -100,12 +100,12 @@ RSpec.describe 'Wiki API', type: :request do
     context 'when params invalid' do
       it 'returns 422 when title blank' do
         post endpoint, params: { title: '', body: 'Hello' }, headers: auth_headers(member)
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
 
       it 'returns 422 when body blank' do
         post endpoint, params: { title: 'Test', body: '' }, headers: auth_headers(member)
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
     end
 
@@ -160,7 +160,7 @@ RSpec.describe 'Wiki API', type: :request do
         put "/wiki/#{page.id}",
             params: { title: 'TestPage', body: '' },
             headers: auth_headers(member)
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:unprocessable_content)
       end
     end
 

backend/spec/requests/wiki_title_collision_spec.rb

@@ -34,7 +34,7 @@ RSpec.describe 'Wiki title collision', type: :request do
         },
         headers: auth_headers(user)
 
-    expect(response).to have_http_status(:unprocessable_entity)
+    expect(response).to have_http_status(:unprocessable_content)
 
     source.reload
 

backend/spec/requests/wiki_unmigrated_contract_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe 'Removed standalone Wiki resources', type: :request do
       before_state = group_state
       post '/wiki', params: { title:, body: 'body' },
            headers: cookie_headers(user)
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:unprocessable_content)
       expect(group_state).to eq(before_state)
     end
   end

frontend/src/components/PostFormTagsArea.tsx

@@ -36,13 +36,10 @@ const replaceToken = (value: string, start: number, end: number, text: string) =
 type Props = Omit<ComponentPropsWithoutRef<'textarea'>, 'value' | 'onChange' | 'onBlur'> & {
     tags:     string
     setTags:  (tags: string) => void
-    label?:   ReactNode
     errors?:  ReactNode[] }
 
 
-const PostFormTagsArea: FC<Props> = (
-    { tags, setTags, label: fieldLabel, errors, ...rest },
-) => {
+const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
   const { label } = useUITranslation ('navigation')
   const locale = useLocale ()
   const ref = useRef<HTMLTextAreaElement> (null)
@@ -120,10 +117,7 @@ const PostFormTagsArea: FC<Props> = (
   }, [locale])
 
   return (
-      <FormField
-	  className="relative w-full"
-	  label={fieldLabel ?? label ('tags')}
-	  messages={errors}>
+      <FormField className="relative w-full" label={label ('tags')} messages={errors}>
 	{({ describedBy, invalid }) => (
 	    <>
 	      <TextArea

frontend/src/components/layout/SidebarComponent.test.tsx

@@ -70,6 +70,16 @@ describe ('SidebarComponent', () => {
     vi.spyOn (HTMLElement.prototype, 'hasPointerCapture').mockReturnValue (true)
   })
 
+  it ('limits sidebar scrolling to desktop to avoid clipping mobile suggestions', () => {
+    renderSidebar ()
+
+    // jsdom has no layout; guard the responsive classes responsible for clipping.
+    const sidebar = screen.getByText ('Sidebar body')
+
+    expect (sidebar).not.toHaveClass ('overflow-y-auto')
+    expect (sidebar).toHaveClass ('md:overflow-y-auto')
+  })
+
   it ('uses maxWidth without applying the container main-width reserve twice', async () => {
     localStorage.setItem ('sidebar:test-sidebar:left:width', '700')
     const onWidthChange = vi.fn ()

frontend/src/components/layout/SidebarComponent.tsx

@@ -339,7 +339,7 @@ const SidebarComponent: FC<Props> = ({
 	  </style>
 	</Helmet>
 
-	<div className="h-full overflow-y-auto p-4 sidebar">
+	<div className="h-full md:overflow-y-auto p-4 sidebar">
 	  {children}
 	</div>
 

frontend/src/pages/tags/NicoTagListPage.test.tsx

@@ -162,13 +162,12 @@ describe ('NicoTagListPage', () => {
     })
   })
 
-  it ('saves links after completing the tag at the cursor', async () => {
+  it ('updates links from a tag card', async () => {
     api.apiGet
       .mockResolvedValueOnce ({
         tags:  [buildNicoTag ({ id: 7, name: 'nico:source' })],
         count: 1,
       })
-      .mockResolvedValueOnce ([buildTag ({ id: 8, name: '連携先', postCount: 3 })])
       .mockResolvedValueOnce ({
         tags: [
           buildNicoTag ({
@@ -184,24 +183,8 @@ describe ('NicoTagListPage', () => {
     renderPage ()
 
     fireEvent.click (await screen.findByRole ('button', { name: '編集' }))
-    const textarea = screen.getByLabelText ('連携する広場タグ')
-    fireEvent.change (textarea, { target: { value: '既存 連携\n後続' } })
-    fireEvent.focus (textarea)
-    fireEvent.select (textarea, {
-	target: { selectionStart: 4, selectionEnd: 4 } })
-
-    await waitFor (() => {
-      expect (api.apiGet).toHaveBeenCalledWith (
-	  '/tags/autocomplete',
-	  { locale: 'ja', params: { q: '連携', nico: '0' },
-	    signal: expect.any (AbortSignal) })
-    })
-    fireEvent.mouseDown (await screen.findByText ('連携先'))
-
-    expect (textarea).toHaveValue ('既存 連携先 \n後続')
-    await waitFor (() => {
-      expect ((textarea as HTMLTextAreaElement).selectionStart).toBe (7)
-      expect ((textarea as HTMLTextAreaElement).selectionEnd).toBe (7)
+    fireEvent.change (screen.getByLabelText ('連携する広場タグ'), {
+      target: { value: '連携先' },
     })
     fireEvent.click (screen.getByRole ('button', { name: '保存' }))
 
@@ -212,8 +195,6 @@ describe ('NicoTagListPage', () => {
           { locale: 'ja', headers: { 'Content-Type': 'multipart/form-data' } },
       )
     })
-    const payload = api.apiPut.mock.calls[0][1] as FormData
-    expect (payload.get ('tags')).toBe ('既存 連携先 \n後続')
     expect (await screen.findByText ('1 件')).toBeInTheDocument ()
   })
 

frontend/src/pages/tags/NicoTagListPage.tsx

@@ -6,10 +6,11 @@ import { useLocation } from 'react-router-dom'
 import { useLocale, useLocaleNavigate } from '@/lib/useLocale'
 import TagLink from '@/components/TagLink'
 import SortHeader from '@/components/SortHeader'
-import PostFormTagsArea from '@/components/PostFormTagsArea'
+import FieldError from '@/components/common/FieldError'
 import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
 import Pagination from '@/components/common/Pagination'
+import TextArea from '@/components/common/TextArea'
 import useDialogue from '@/lib/dialogues/useDialogue'
 import MainArea from '@/components/layout/MainArea'
 import { toast } from '@/components/ui/use-toast'
@@ -356,18 +357,21 @@ const NicoTagListPage: FC<Props> = ({ user }) => {
 					       dark:bg-rose-950/30">
 				  <td colSpan={editable ? 5 : 4} className="p-3">
 				    <div className="space-y-2">
-				      <PostFormTagsArea
+				      <label htmlFor={`nico-links-${ tag.id }`}
+					     className="block text-sm font-semibold">
+					{label ('nico.tagsToLink')}
+				      </label>
+				      <TextArea
 					  id={`nico-links-${ tag.id }`}
-					  label={label ('nico.tagsToLink')}
-					  aria-label={message ('nico.tagsToLink').text}
-					  tags={rawTags[tag.id] ?? ''}
-					  errors={errors}
+					  value={rawTags[tag.id] ?? ''}
+					  invalid={(errorsByTagId[tag.id] ?? []).length > 0}
 					  className="min-h-24 resize-y"
 					  placeholder={message ('nico.tagsPlaceholder').text}
 					  lang={message ('nico.tagsPlaceholder').language}
-					  setTags={value => setRawTags (rawTags => ({
+					  onChange={e => setRawTags (rawTags => ({
 					      ...rawTags,
-					      [tag.id]: value}))}/>
+					      [tag.id]: e.target.value}))}/>
+				      <FieldError messages={errors}/>
 				      <div className="flex justify-end gap-2">
 					<button
 					    type="button"

frontend/src/pages/tags/TagDetailPage.test.tsx

@@ -35,6 +35,10 @@ const renderPage = () =>
 describe ('TagDetailPage', () => {
   beforeEach (() => {
     vi.clearAllMocks ()
+    tagsApi.fetchTag.mockReset ()
+    api.apiPut.mockReset ()
+    api.isApiError.mockReset ()
+    toastApi.toast.mockReset ()
     api.isApiError.mockReturnValue (false)
   })
 
@@ -51,8 +55,11 @@ describe ('TagDetailPage', () => {
   })
 
   it ('submits edited tag fields', async () => {
-    tagsApi.fetchTag.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
-    api.apiPut.mockResolvedValueOnce (buildTag ({ id: 7, name: 'new', aliases: ['alias'] }))
+    const updatedTag = buildTag ({ id: 7, name: 'new', aliases: ['alias'] })
+    tagsApi.fetchTag
+	.mockResolvedValue (updatedTag)
+	.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
+    api.apiPut.mockResolvedValueOnce (updatedTag)
 
     renderPage ()