#351

Reviewed-on: #350

.gitea/ISSUE_TEMPLATE.md

@@ -0,0 +1,35 @@
+## 背景
+
+なぜ必要か。
+
+## 対象範囲
+
+- backend:
+- frontend:
+- docs:
+- migration:
+
+## やること
+
+- [ ] 
+
+## 受け入れ条件
+
+- [ ] 
+
+## 実行すべき確認
+
+- [ ] `cd backend && bundle exec rspec`
+- [ ] `cd frontend && npm run build`
+- [ ] `cd frontend && npm run lint`
+
+## 禁止事項
+
+- unrelated refactor はしない
+- 既存 API response shape を壊さない
+- 認証・認可・BAN を弱めない
+
+## Codex への指示
+
+この issue を読んで実装してください。
+不明点があれば、実装前に調査結果と選択肢を提示してください。

AGENTS.md

@@ -0,0 +1,143 @@
+# AGENTS.md
+
+## Project overview
+
+BTRC Hub / タグ広場 is a split Rails API and React frontend repository.
+
+- Backend: Rails API under `backend/`.
+- Frontend: React + TypeScript + Vite under `frontend/`.
+- Docs: lightweight command notes under `docs/`.
+- There is no README or Makefile at the repository root as of this inspection.
+
+## Stack
+
+- Backend: Ruby `3.2.2` from `backend/.ruby-version`, Rails `~> 8.0.2`.
+- Backend dependencies include `mysql2`, `sqlite3`, `rspec-rails`, `factory_bot_rails`, `rack-cors`, `jwt`, `discard`, `gollum`, `whenever`, `aws-sdk-s3`, `brakeman`, and `rubocop-rails-omakase`.
+- Frontend: React `^19.1.0`, TypeScript `~5.8.3`, Vite `^6.3.5`.
+- Frontend data/UI dependencies include Axios, TanStack Query, Tailwind CSS, Framer Motion, Radix UI components, lucide-react, MDX/Markdown tooling, and Zustand.
+
+## Main directories
+
+- `backend/app/controllers`: Rails API controllers.
+- `backend/app/models`: Active Record models.
+- `backend/app/representations`: API response representation classes.
+- `backend/app/services`: domain services such as version recording, wiki commit, YouTube sync, and similarity calculation.
+- `backend/config/routes.rb`: API routes.
+- `backend/db/migrate`: migrations.
+- `backend/db/schema.rb`: current schema snapshot.
+- `backend/lib/tasks`: custom Rake tasks.
+- `backend/spec`: RSpec tests.
+- `backend/test`: Rails minitest files that still exist in the tree.
+- `frontend/src/App.tsx`: frontend route definitions and initial user setup.
+- `frontend/src/pages`: page-level React components.
+- `frontend/src/components`: shared and feature components.
+- `frontend/src/lib`: API client helpers, query keys, prefetchers, and domain helpers.
+- `frontend/src/stores`: Zustand stores.
+- `docs/commands.md`: command notes.
+
+## Commands
+
+Only list commands that are backed by files inspected in this repository.
+
+### Backend
+
+The following binstubs exist under `backend/bin`:
+
+```sh
+cd backend
+bin/setup
+bin/dev
+bin/rails
+bin/rake
+bin/rubocop
+bin/brakeman
+bin/kamal
+bin/thrust
+```
+
+Common Rails/Rake usage through existing binstubs:
+
+```sh
+cd backend
+bin/rails db:prepare
+bin/rails db:migrate
+bin/rails routes
+bin/rails server
+bin/rake
+bin/rubocop
+bin/brakeman
+```
+
+RSpec is present in `Gemfile` and `.rspec` exists:
+
+```sh
+cd backend
+bundle exec rspec
+```
+
+### Frontend
+
+The following npm scripts exist in `frontend/package.json`:
+
+```sh
+cd frontend
+npm run dev
+npm run build
+npm run lint
+npm run preview
+```
+
+`npm run build` runs `tsc -b && vite build`, then `postbuild` runs `node scripts/generate-sitemap.js`.
+
+Do not write or report `npm test` as a repository command unless a `test` script is added to `frontend/package.json`.
+
+## Coding style
+
+- Prefer precise, minimal changes.
+- Do not flatter or over-explain.
+- Explain risks directly.
+- Prefer single quotes for strings unless interpolation or escaping makes double quotes better.
+- Ruby: never put a space before method-call parentheses.
+- Ruby: do not use `%w` or `%i`.
+- TypeScript and Python: use GNU-style spacing before parentheses where syntactically valid.
+- Do not add production dependencies without explicit approval.
+
+## Backend rules
+
+- Inspect existing routes, controllers, models, services, and specs before editing backend behavior.
+- For API behavior changes, add or update request specs under `backend/spec/requests`.
+- Prefer RSpec for new backend tests; existing minitest files under `backend/test` do not make minitest the default for new coverage.
+- Do not weaken authentication, BAN user checks, or IP BAN checks.
+- Preserve the `X-Transfer-Code` user identification flow unless the task explicitly changes authentication.
+- Be careful with version tables, `version_no`, optimistic concurrency, wiki revisions, and restore/diff behavior.
+- Be careful with tag names, tag normalization, implications, similarities, and discard behavior.
+- Keep migration files and `backend/db/schema.rb` consistent when changing schema.
+
+## Frontend rules
+
+- Use `frontend/src/lib/api.ts` for API calls so headers and camelCase conversion stay consistent.
+- Add or reuse TanStack Query keys through `frontend/src/lib/queryKeys.ts`; avoid ad hoc query key arrays.
+- Encode URL path-segment values with `encodeURIComponent`.
+- React hooks must be called unconditionally.
+- Keep page-level code under `frontend/src/pages` and shared UI/feature code under `frontend/src/components` unless existing patterns point elsewhere.
+- Match existing Tailwind, component, and import alias conventions.
+
+## Codex workflow
+
+- First inspect existing patterns; do not invent new architecture when a local convention exists.
+- Keep changes scoped to the requested issue.
+- Do not scan or summarize dependency/generated/runtime directories such as `node_modules`, `dist`, `tmp`, `log`, and `storage` unless explicitly needed.
+- Before touching wiki, tag, versioning, BAN, IP BAN, or authentication behavior, inspect the related request specs and service objects.
+- If frontend code changes, run the existing frontend verification commands that apply: `npm run build` and `npm run lint`.
+- If backend code changes, run the relevant RSpec command; for broad backend changes, run `bundle exec rspec`.
+- If a verification command cannot be run or fails, report the exact command and failure.
+
+## Completion criteria
+
+A task is complete only when:
+
+- implementation is complete,
+- relevant verification commands pass, or failures are clearly explained,
+- unrelated files are not changed,
+- migrations and schema are consistent when schema changes are made,
+- user-facing behavior is documented when needed.

backend/AGENTS.md

@@ -0,0 +1,147 @@
+# backend/AGENTS.md
+
+## Scope
+
+These rules apply to work under `backend/`.
+
+This is a Rails API app using Active Record, RSpec, request specs, service objects, representation classes, and version tables for post/tag/wiki history.
+
+## Commands
+
+Use commands backed by files and dependencies in this directory:
+
+```sh
+bin/setup
+bin/dev
+bin/rails
+bin/rake
+bin/rubocop
+bin/brakeman
+bundle exec rspec
+```
+
+Common checks:
+
+```sh
+bundle exec rspec
+bin/rubocop
+bin/brakeman
+```
+
+Common Rails commands:
+
+```sh
+bin/rails db:prepare
+bin/rails db:migrate
+bin/rails routes
+bin/rails server
+```
+
+After backend behavior changes, run the relevant RSpec files. For broad backend changes, run:
+
+```sh
+bundle exec rspec
+```
+
+If a command cannot be run or fails, report the exact command and failure.
+
+## Rails structure
+
+- `app/controllers`: API controllers.
+- `app/models`: Active Record models and concerns.
+- `app/representations`: JSON response shaping.
+- `app/services`: domain services such as version recorders, wiki commit, YouTube sync, and similarity calculation.
+- `config/routes.rb`: public API routes.
+- `db/migrate`: migrations.
+- `db/schema.rb`: schema snapshot.
+- `lib/tasks`: custom Rake tasks.
+- `spec`: RSpec tests.
+
+Before changing behavior, inspect the matching route, controller, model, service, representation, and spec.
+
+## Ruby style
+
+- Prefer precise, minimal changes.
+- Use single quotes unless interpolation or escaping makes double quotes better.
+- Do not put a space before Ruby method-call parentheses.
+- Do not use `%w` or `%i` in new Ruby code.
+- Keep comments short and useful; avoid narrating obvious code.
+- Do not add production dependencies without approval.
+
+## Authentication and authorization
+
+- Authentication is handled through the `X-Transfer-Code` header in `ApplicationController#authenticate_user`.
+- `current_user` is set by looking up `User.inheritance_code`.
+- Do not bypass or weaken the `X-Transfer-Code` flow unless the task explicitly changes authentication.
+- Unauthenticated write actions should return `:unauthorized` consistently with existing controllers.
+- Role checks use `User` enum roles: `guest`, `member`, and `admin`.
+- Use `current_user.gte_member?` for member-or-admin write permissions where existing controllers do so.
+- Use `current_user.admin?` only for admin-only paths, such as tag child relationship changes.
+- Do not replace role checks with looser presence checks.
+
+## BAN and IP BAN
+
+- `ApplicationController` runs these before actions in order:
+  - `reject_banned_ip_address!`
+  - `authenticate_user`
+  - `reject_banned_user!`
+- User and IP bans use `banned_at`, not a boolean `banned` column.
+- `User#banned?` and `IpAddress#banned?` check `banned_at.present?`.
+- Do not weaken BAN or IP BAN behavior.
+- If changing request authentication or controller before actions, add or update request specs covering banned users and banned IP addresses.
+
+## RSpec
+
+- Prefer RSpec for new backend tests.
+- Put API behavior coverage under `spec/requests`.
+- Put model behavior under `spec/models`.
+- Put service behavior under `spec/services`.
+- Put Rake task coverage under `spec/tasks`.
+- `spec/rails_helper.rb` loads `spec/support/**/*.rb`.
+- Request specs include `AuthHelper` and `JsonHelper`.
+- `AuthHelper#sign_in_as(user)` stubs `ApplicationController#current_user`; use it when matching existing request spec style.
+- Add or update request specs for API behavior changes, especially status codes, permissions, response shape, and version conflict behavior.
+
+## Migrations
+
+- Keep migrations and `db/schema.rb` consistent.
+- Use reversible migrations where practical; otherwise define explicit `up` and `down`.
+- For data backfills inside migrations, follow the existing pattern of defining migration-local `ActiveRecord::Base` classes with `self.table_name`.
+- Preserve existing indexes, foreign keys, check constraints, and null constraints.
+- Be careful with MySQL-specific options already present in migrations, such as `after:`.
+- Do not edit old migrations just to change current behavior unless explicitly requested; add a new migration.
+
+## Version tables
+
+- Versioned records include posts, tags, nico tags, and wiki pages.
+- Current records have `version_no`; version tables have positive `version_no` with unique indexes scoped to the parent record.
+- Version event types are `create`, `update`, `discard`, and `restore`.
+- Version rows are readonly through the `VersionRecord` concern.
+- Use the existing recorder services instead of manually inserting version rows in application code:
+  - `PostVersionRecorder`
+  - `TagVersionRecorder`
+  - `NicoTagVersionRecorder`
+  - `WikiVersionRecorder`
+  - `TagVersioning`
+- `VersionRecorder` locks the current record, validates sequence consistency, skips unchanged update snapshots, creates the next version row, and updates the record `version_no`.
+- Do not update versioned records without considering whether a version snapshot must be created.
+- For optimistic concurrency paths, preserve `base_version_no`, `force`, and `merge` semantics and cover conflicts in request specs.
+
+## Domain cautions
+
+- Posts have tag snapshots, parent post implications, original-created ranges, viewed state, and version conflict behavior.
+- Tags have canonical names, aliases through `TagName`, categories, parent implications, discard behavior, and version snapshots.
+- Nico tags have separate relation/version behavior; do not treat them like normal editable tags without checking existing code.
+- Wiki pages involve page content, revisions/history, version rows, title/tag-name behavior, and diff/restore paths.
+- Materials, theatres, and comments have user and permission checks; inspect the controller before changing them.
+
+## API responses
+
+- Use representation classes under `app/representations` when existing endpoints do.
+- Keep response keys consistent with existing JSON contracts; frontend code expects camelCase conversion client-side, while Rails params 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 validation failures.
+
+## Files to avoid in routine work
+
+- Do not inspect or edit `tmp/`, `log/`, `storage/`, `vendor/`, or dependency directories unless explicitly needed.
+- Do not modify generated schema or migration output without the corresponding migration when schema changes are made.

backend/app/controllers/posts_controller.rb

@@ -95,7 +95,8 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+    post = filtered_posts
+           .preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
            .order('RAND()')
            .first
     return head :not_found unless post
@@ -108,7 +109,7 @@ class PostsController < ApplicationController
     return head :not_found unless post
 
     render json: PostRepr.base(post, current_user)
-                         .merge(tags: build_tag_tree_for(post.tags),
+                         .merge(tags: build_tag_tree_for(post),
                                 related: PostRepr.many(post.related(limit: 20)))
   end
 
@@ -132,11 +133,11 @@ class PostsController < ApplicationController
     ApplicationRecord.transaction do
       post.save!
 
-      tags = Tag.normalise_tags!(tag_names)
+      Tag.normalise_tags!(tag_names, with_sections: true) => { tags:, sections: }
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
       tags = Tag.expand_parent_tags(tags)
-      sync_post_tags!(post, tags)
+      sync_post_tags!(post, tags, sections)
 
       sync_parent_posts!(post, parent_post_ids)
 
@@ -177,8 +178,8 @@ class PostsController < ApplicationController
     merge = bool?(:merge)
     return head :bad_request if force && merge
 
-    base_version_no = nil
+    base_version_no = parse_base_version_no
-    base_version_no = parse_base_version_no unless force
+    return head :bad_request if !(force) && !(base_version_no)
 
     title = params[:title].presence
     tag_names = params[:tags].to_s.split
@@ -235,7 +236,7 @@ class PostsController < ApplicationController
 
     post.reload
     json = PostRepr.base(post, current_user)
-    json['tags'] = build_tag_tree_for(post.tags)
+    json['tags'] = build_tag_tree_for(post)
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
     head :bad_request
@@ -337,7 +338,7 @@ class PostsController < ApplicationController
   def tagged_post_ids_for(name) =
       Post.joins(tags: :tag_name).where(tag_names: { name: }).select(:id)
 
-  def sync_post_tags! post, desired_tags
+  def sync_post_tags! post, desired_tags, sections
     desired_tags.each do |t|
       t.save! if t.new_record?
     end
@@ -356,13 +357,20 @@ class PostsController < ApplicationController
       end
     end
 
+    PostTagSection.where(post_id: post.id).destroy_all
+    sections.each do |tag_id, ranges|
+      ranges.each do |begin_ms, end_ms|
+        PostTagSection.create!(post_id: post.id, tag_id:, begin_ms:, end_ms:)
+      end
+    end
+
     PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
       pt.discard_by!(current_user)
     end
   end
 
-  def build_tag_tree_for tags
+  def build_tag_tree_for post
-    tags = tags.to_a
+    tags = post.tags.to_a
     tag_ids = tags.map(&:id)
 
     implications = TagImplication.where(parent_tag_id: tag_ids, tag_id: tag_ids)
@@ -384,8 +392,11 @@ class PostsController < ApplicationController
       tag = tags_by_id[tag_id]
       return nil unless tag
 
+      sections = PostTagSection.where(post_id: post.id, tag_id:)
+                 .as_json(only: [:begin_ms, :end_ms])
+
       if path.include?(tag_id)
-        return TagRepr.base(tag).merge(children: [])
+        return TagRepr.base(tag).merge(children: [], sections:)
       end
 
       if memo.key?(tag_id)
@@ -397,7 +408,7 @@ class PostsController < ApplicationController
 
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
-      memo[tag_id] = TagRepr.base(tag).merge(children:)
+      memo[tag_id] = TagRepr.base(tag).merge(children:, sections:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }
@@ -408,7 +419,7 @@ class PostsController < ApplicationController
 
     params[:parent_post_ids].to_s.split.map { |token|
       id = Integer(token, exception: false)
-      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if id.nil? || id <= 0
+      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if !(id) || id <= 0
 
       id
     }.uniq
@@ -442,9 +453,11 @@ class PostsController < ApplicationController
 
   def parse_base_version_no
     version_no = Integer(params[:base_version_no], exception: false)
-    raise ArgumentError, 'base_version_no は必須です．' unless version_no&.positive?
+    if version_no&.positive?
-
       version_no
+    else
+      nil
+    end
   end
 
   def post_snapshot_from_version version
@@ -468,7 +481,21 @@ class PostsController < ApplicationController
   end
 
   def editable_tag_names_from_post post
-    post.tags.not_nico.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+    post
+        .post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .merge(Tag.not_nico)
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
   end
 
   def post_incoming_snapshot title:, original_created_from:, original_created_before:,
@@ -500,9 +527,16 @@ class PostsController < ApplicationController
   end
 
   def incoming_tag_names_for_snapshot raw_tag_names
-    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false)
+    Tag.normalise_tags!(raw_tag_names, with_tagme: false, with_sections: true) =>
+        { tags:, sections: }
 
-    Tag.expand_parent_tags(tags).map(&:name).uniq.sort
+    Tag.expand_parent_tags(tags).uniq(&:id).map { |tag|
+      "#{ tag.name }#{ sections[tag.id].to_a.map { section_literal(_1) }.join }"
+    }.sort
+  end
+
+  def section_literal section
+    "[#{ Post.ms_to_time(section[0]) }-#{ Post.ms_to_time(section[1]) }]"
   end
 
   def post_conflict_json post:, base_version_no:, base_snapshot:,
@@ -589,7 +623,8 @@ class PostsController < ApplicationController
                  original_created_from: snapshot[:original_created_from],
                  original_created_before: snapshot[:original_created_before])
 
-    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false)
+    Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false, with_sections: true) =>
+        { tags: editable_tags, sections: }
     TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
 
     readonly_tags = post.tags.nico.to_a
@@ -597,7 +632,7 @@ class PostsController < ApplicationController
     tags = readonly_tags + editable_tags
     tags = Tag.expand_parent_tags(tags)
 
-    sync_post_tags!(post, tags)
+    sync_post_tags!(post, tags, sections)
     sync_parent_posts!(post, snapshot[:parent_post_ids])
 
     PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)

backend/app/models/post.rb

@@ -56,7 +56,38 @@ class Post < ApplicationRecord
     super(options).merge(thumbnail: nil)
   end
 
-  def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+  def snapshot_tag_names
+    post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
+  end
+
+  def self.section_literal section
+    "[#{ Post.ms_to_time(section.begin_ms) }-#{ Post.ms_to_time(section.end_ms) }]"
+  end
+
+  def self.ms_to_time ms
+    total_s = ms / 1_000
+    s = total_s % 60
+    min = (total_s / 60) % 60
+    h = total_s / 3_600
+
+    if h.positive?
+      '%d:%02d:%02d' % [h, min, s]
+    else
+      '%d:%02d' % [min, s]
+    end
+  end
 
   def snapshot_parent_post_ids = parents.order(:id).pluck(:id)
 

backend/app/models/post_tag.rb

@@ -10,6 +10,12 @@ class PostTag < ApplicationRecord
   belongs_to :created_user, class_name: 'User', optional: true
   belongs_to :deleted_user, class_name: 'User', optional: true
 
+  has_many :sections, -> { order(:begin_ms) }, class_name: 'PostTagSection',
+                                               foreign_key: [:post_id, :tag_id],
+                                               primary_key: [:post_id, :tag_id],
+                                               dependent: :delete_all,
+                                               inverse_of: :post_tag
+
   validates :post_id, presence: true
   validates :tag_id, presence: true
   validates :post_id, uniqueness: {

backend/app/models/post_tag_section.rb

@@ -0,0 +1,20 @@
+class PostTagSection < ApplicationRecord
+  self.primary_key = :post_id, :tag_id, :begin_ms
+
+  belongs_to :post
+  belongs_to :tag
+
+  belongs_to :post_tag, -> { kept }, foreign_key: [:post_id, :tag_id],
+                                     primary_key: [:post_id, :tag_id],
+                                     inverse_of: :sections,
+                                     optional: true
+
+  validates :post_id, presence: true
+  validates :tag_id, presence: true
+
+  validates :begin_ms, presence: true,
+                       numericality: { only_integer: true, greater_than_or_equal_to: 0 }
+
+  validates :end_ms, presence: true,
+                     numericality: { only_integer: true, greater_than: :begin_ms }
+end

backend/app/models/tag.rb

@@ -92,22 +92,50 @@ class Tag < ApplicationRecord
 
   def self.normalise_tags! tag_names, with_tagme: true,
                                       with_no_deerjikist: true,
-                                      deny_nico: true
+                                      deny_nico: true,
+                                      with_sections: false
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end
 
+    sections = { }
     tags = tag_names.map do |name|
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
-      name = TagName.canonicalise(name.sub(/\A#{ pf }/i, '')).first
+
+      name = name.sub(/\A#{ pf }/i, '')
+
+      sections_by_tag = []
+      while n = name.sub!(/^(\S*?)\[([0-9:.]*?)-([0-9:.]*?)\](\S*?)$/, '\1\4 \2 \3')
+        name, *section_raw = n.split
+
+        begin_ms, end_ms = section_raw.map { time_to_ms(_1) }
+        next if begin_ms == end_ms
+
+        begin_ms, end_ms = end_ms, begin_ms if begin_ms > end_ms
+
+        sections_by_tag << [begin_ms, end_ms]
+      end
+
+      name = TagName.canonicalise(name).first
+
       find_or_create_by_tag_name!(name, category: (cat || :general)).tap do |tag|
         tag.update!(category: cat) if cat && tag.category != cat
+        next if sections_by_tag.empty?
+
+        sections[tag.id] ||= []
+        sections[tag.id].concat(sections_by_tag)
       end
     end
 
     tags << Tag.tagme if with_tagme && tags.size < 10 && tags.none?(Tag.tagme)
     tags << Tag.no_deerjikist if with_no_deerjikist && tags.all? { |t| !(t.deerjikist?) }
-    tags.uniq(&:id)
+    tags.uniq!(&:id)
+
+    if with_sections
+      { tags:, sections: }
+    else
+      tags
+    end
   end
 
   def self.expand_parent_tags tags
@@ -228,4 +256,23 @@ class Tag < ApplicationRecord
       errors.add :category, 'ニジラーと紐づいてゐるタグはニジラー・カテゴリである必要があります．'
     end
   end
+
+  def self.time_to_ms str
+    parts = str.split(':')
+
+    s_part = parts.pop
+    s, ms = s_part.split('.')
+
+    total_s = s.to_i
+
+    if parts.length >= 1
+      total_s += parts.pop.to_i * 60
+    end
+
+    if parts.length >= 1
+      total_s += parts.pop.to_i * 3_600
+    end
+
+    total_s * 1_000 + ms.to_s.ljust(3, '0')[0, 3].to_i
+  end
 end

backend/app/services/version_recorder.rb

@@ -16,7 +16,7 @@ class VersionRecorder
       @record = record_class.unscoped.lock.find(@record.id)
       latest = latest_version
 
-      validate_version_sequence! latest
+      validate_version_sequence!(latest)
 
       attrs = snapshot_attributes
 
@@ -27,7 +27,7 @@ class VersionRecorder
       version = version_class.create!(
           base_attributes(latest).merge(record_key => @record).merge(attrs))
 
-      update_record_version_no! version.version_no
+      update_record_version_no!(version.version_no)
 
       version
     end
@@ -47,7 +47,7 @@ class VersionRecorder
   end
 
   def update_record_version_no! version_no
-    @record.update_columns version_no: version_no
+    @record.update_columns(version_no:)
     @record.version_no = version_no
   end
 

backend/db/migrate/20260518235300_create_post_tag_sections.rb

@@ -0,0 +1,19 @@
+class CreatePostTagSections < ActiveRecord::Migration[8.0]
+  def change
+    create_table :post_tag_sections, primary_key: [:post_id, :tag_id, :begin_ms] do |t|
+      t.references :post, null: false, foreign_key: true, index: false
+      t.references :tag, null: false, foreign_key: true, index: false
+      t.integer :begin_ms, null: false
+      t.integer :end_ms, null: false
+      t.timestamps
+
+      t.index [:post_id, :begin_ms], name: 'idx_post_tag_sections_post_id_begin_ms'
+
+      t.check_constraint 'begin_ms >= 0',
+                         name: 'chk_post_tag_sections_begin_ms_natural'
+
+      t.check_constraint 'begin_ms < end_ms',
+                         name: 'chk_post_tag_sections_end_ms_after_begin_ms'
+    end
+  end
+end

backend/db/migrate/20260519013100_add_video_ms_to_posts.rb

@@ -0,0 +1,9 @@
+class AddVideoMsToPosts < ActiveRecord::Migration[8.0]
+  def change
+    add_column :posts, :video_ms, :integer
+    add_index :posts, [:video_ms, :id], name: 'idx_posts_video_ms_id'
+
+    add_check_constraint :posts, 'video_ms IS NULL OR video_ms > 0',
+                         name: 'chk_posts_video_ms_positive'
+  end
+end

backend/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_19_013100) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -137,6 +137,19 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
+  create_table "post_tag_sections", primary_key: ["post_id", "tag_id", "begin_ms"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.bigint "post_id", null: false
+    t.bigint "tag_id", null: false
+    t.integer "begin_ms", null: false
+    t.integer "end_ms", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["post_id", "begin_ms"], name: "idx_post_tag_sections_post_id_begin_ms"
+    t.index ["tag_id"], name: "fk_rails_8be3847903"
+    t.check_constraint "`begin_ms` < `end_ms`", name: "chk_post_tag_sections_end_ms_after_begin_ms"
+    t.check_constraint "`begin_ms` >= 0", name: "chk_post_tag_sections_begin_ms_natural"
+  end
+
   create_table "post_tags", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "tag_id", null: false
@@ -187,8 +200,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.datetime "original_created_before"
     t.datetime "updated_at", null: false
     t.integer "version_no", null: false
+    t.integer "video_ms"
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
+    t.index ["video_ms", "id"], name: "idx_posts_video_ms_id"
+    t.check_constraint "(`video_ms` is null) or (`video_ms` > 0)", name: "chk_posts_video_ms_positive"
     t.check_constraint "`version_no` > 0", name: "chk_posts_version_no_positive"
   end
 
@@ -290,6 +306,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["expires_at"], name: "index_theatre_watching_users_on_expires_at"
+    t.index ["theatre_id", "expires_at"], name: "idx_on_theatre_id_skip_expires_at_4c8de1dd42"
     t.index ["theatre_id", "expires_at"], name: "index_theatre_watching_users_on_theatre_id_and_expires_at"
     t.index ["theatre_id"], name: "index_theatre_watching_users_on_theatre_id"
     t.index ["user_id"], name: "index_theatre_watching_users_on_user_id"
@@ -446,6 +463,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
   add_foreign_key "post_implications", "posts", column: "parent_post_id"
   add_foreign_key "post_similarities", "posts"
   add_foreign_key "post_similarities", "posts", column: "target_post_id"
+  add_foreign_key "post_tag_sections", "posts"
+  add_foreign_key "post_tag_sections", "tags"
   add_foreign_key "post_tags", "posts"
   add_foreign_key "post_tags", "tags"
   add_foreign_key "post_tags", "users", column: "created_user_id"

backend/spec/factories/post_tag_sections.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :post_tag_section do
+    association :post
+    association :tag
+    begin_ms { 1_000 }
+    end_ms { 2_000 }
+  end
+end

backend/spec/factories/post_tags.rb

@@ -0,0 +1,6 @@
+FactoryBot.define do
+  factory :post_tag do
+    association :post
+    association :tag
+  end
+end

backend/spec/factories/posts.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :post do
+    sequence(:url) { |n| "https://example.com/factory-post-#{ n }" }
+    title { 'factory post' }
+    thumbnail_base { nil }
+    uploaded_user { nil }
+  end
+end

backend/spec/models/post_tag_spec.rb

@@ -0,0 +1,29 @@
+RSpec.describe PostTag, type: :model do
+  describe '#sections' do
+    it 'loads sections by post_id and tag_id' do
+      post_tag = create(:post_tag)
+      section = create(:post_tag_section,
+                       post: post_tag.post,
+                       tag: post_tag.tag,
+                       begin_ms: 1000,
+                       end_ms: 2000)
+
+      expect(post_tag.sections).to contain_exactly(section)
+    end
+
+    it 'does not load sections for another tag on the same post' do
+      post = create(:post)
+      tag = create(:tag)
+      other_tag = create(:tag)
+
+      post_tag = create(:post_tag, post:, tag:)
+      create(:post_tag_section,
+             post:,
+             tag: other_tag,
+             begin_ms: 1000,
+             end_ms: 2000)
+
+      expect(post_tag.sections).to be_empty
+    end
+  end
+end

backend/spec/requests/posts_spec.rb

@@ -10,6 +10,10 @@ RSpec.describe 'Posts API', type: :request do
     allow_any_instance_of(Post).to receive(:resized_thumbnail!).and_return(true)
   end
 
+  def create_nico_tag!(name)
+    Tag.find_or_create_by_tag_name!(name, category: :nico)
+  end
+
   def dummy_upload
     # 中身は何でもいい（加工処理はスタブしてる）
     Rack::Test::UploadedFile.new(StringIO.new('dummy'), 'image/jpeg', original_filename: 'dummy.jpg')
@@ -23,7 +27,8 @@ RSpec.describe 'Posts API', type: :request do
     Post.create!(title:, url:)
   end
 
-  def create_post_version_for! post
+  def create_post_version_for!(post)
+    version =
         PostVersion.create!(
             post:,
             version_no: 1,
@@ -36,8 +41,20 @@ RSpec.describe 'Posts API', type: :request do
             original_created_from: post.original_created_from,
             original_created_before: post.original_created_before,
             created_at: post.created_at,
-      created_by_user: post.uploaded_user
+            created_by_user: post.uploaded_user)
-    )
+
+    post.update_columns(version_no: version.version_no) if post.has_attribute?(:version_no)
+    post.version_no = version.version_no if post.respond_to?(:version_no=)
+
+    version
+  end
+
+  def post_update_params(post, params = { })
+    base_version =
+        post.post_versions.order(version_no: :desc).first ||
+        create_post_version_for!(post.reload)
+
+    post_write_params({ base_version_no: base_version.version_no }.merge(params))
   end
 
   let!(:tag_name) { TagName.create!(name: 'spec_tag') }
@@ -806,24 +823,26 @@ RSpec.describe 'Posts API', type: :request do
 
     it '401 when not logged in' do
       sign_out
-      put "/posts/#{post_record.id}", params: post_write_params(title: 'updated', tags: 'spec_tag')
+      put "/posts/#{post_record.id}", params: post_update_params(
+          post_record, title: 'updated', tags: 'spec_tag')
       expect(response).to have_http_status(:unauthorized)
     end
 
     it '403 when not member' do
       sign_in_as(create(:user, role: 'guest'))
-      put "/posts/#{post_record.id}", params: post_write_params(title: 'updated', tags: 'spec_tag')
+      put "/posts/#{post_record.id}", params: post_update_params(
+          post_record, title: 'updated', tags: 'spec_tag')
       expect(response).to have_http_status(:forbidden)
     end
 
     it '200 and updates title + resync tags when member' do
       sign_in_as(member)
 
-      # 追加で別タグも作って、更新時に入れ替わることを見る
       tn2 = TagName.create!(name: 'spec_tag_2')
       Tag.create!(tag_name: tn2, category: :general)
 
-      put "/posts/#{post_record.id}", params: post_write_params(
+      put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag_2')
 
@@ -831,7 +850,6 @@ RSpec.describe 'Posts API', type: :request do
       expect(json).to have_key('tags')
       expect(json['tags']).to be_an(Array)
 
-      # show と同様、update 後レスポンスもツリー形式
       names = json['tags'].map { |n| n['name'] }
       expect(names).to include('spec_tag_2')
     end
@@ -846,10 +864,10 @@ RSpec.describe 'Posts API', type: :request do
       it 'return 400' do
         sign_in_as(member)
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+            post_record,
             title: 'updated title',
-          tags: 'nico:nico_tag'
+            tags: 'nico:nico_tag')
-        )
 
         expect(response).to have_http_status(:bad_request), response.body
       end
@@ -887,11 +905,11 @@ RSpec.describe 'Posts API', type: :request do
       it 'replaces parent posts' do
         sign_in_as(member)
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+            post_record,
             title: 'updated title',
             tags: 'spec_tag',
-          parent_post_ids: "#{new_parent_post_1.id} #{new_parent_post_2.id}"
+            parent_post_ids: "#{new_parent_post_1.id} #{new_parent_post_2.id}")
-        )
 
         expect(response).to have_http_status(:ok)
 
@@ -908,7 +926,8 @@ RSpec.describe 'Posts API', type: :request do
       it 'clears parent posts when parent_post_ids is blank' do
         sign_in_as(member)
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag',
           parent_post_ids: ''
@@ -922,7 +941,8 @@ RSpec.describe 'Posts API', type: :request do
         sign_in_as(member)
         create_post_version_for!(post_record.reload)
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag',
           parent_post_ids: "#{new_parent_post_1.id} #{new_parent_post_2.id}"
@@ -943,7 +963,10 @@ RSpec.describe 'Posts API', type: :request do
       it 'returns 422' do
         sign_in_as(member)
 
+        base_version = create_post_version_for!(post_record.reload)
+
         put "/posts/#{post_record.id}", params: {
+            base_version_no: base_version.version_no,
             title: 'updated title',
             tags: 'spec_tag' }
 
@@ -966,7 +989,8 @@ RSpec.describe 'Posts API', type: :request do
           parent_post:
         )
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag',
           parent_post_ids: 'abc'
@@ -991,7 +1015,8 @@ RSpec.describe 'Posts API', type: :request do
           parent_post:
         )
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag',
           parent_post_ids: '999999999'
@@ -1006,7 +1031,8 @@ RSpec.describe 'Posts API', type: :request do
       it 'returns 422 and does not create self implication' do
         sign_in_as(member)
 
-        put "/posts/#{post_record.id}", params: post_write_params(
+        put "/posts/#{post_record.id}", params: post_update_params(
+          post_record,
           title: 'updated title',
           tags: 'spec_tag',
           parent_post_ids: post_record.id.to_s
@@ -1020,6 +1046,221 @@ RSpec.describe 'Posts API', type: :request do
         )).to be(false)
       end
     end
+
+    context 'with optimistic locking' do
+      let!(:no_deerjikist_tag) { Tag.no_deerjikist }
+
+      before do
+        PostTag.create!(post: post_record, tag: no_deerjikist_tag)
+      end
+
+      it '400 when base_version_no is missing without force' do
+        sign_in_as(member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            title: 'updated title',
+            tags: 'spec_tag')
+
+        expect(response).to have_http_status(:bad_request)
+      end
+
+      it '400 when force and merge are both true' do
+        sign_in_as(member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            title: 'updated title',
+            tags: 'spec_tag',
+            force: '1',
+            merge: '1')
+
+        expect(response).to have_http_status(:bad_request)
+      end
+
+      it '409 when scalar fields are changed both by current and incoming updates' do
+        sign_in_as(member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        post_record.update!(title: 'updated by other user')
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: 'updated by me',
+            tags: "spec_tag #{Tag.no_deerjikist.name}")
+
+        expect(response).to have_http_status(:conflict)
+
+        expect(json.fetch('error')).to eq('conflict')
+        expect(json.fetch('base_version_no')).to eq(base_version.version_no)
+        expect(json.fetch('current_version_no')).to eq(2)
+        expect(json.fetch('mergeable')).to be(false)
+
+        conflict_fields = json.fetch('conflicts').map { |change| change.fetch('field') }
+        expect(conflict_fields).to include('title')
+
+        expect(post_record.reload.title).to eq('updated by other user')
+      end
+
+      it 'returns 409 with mergeable true when stale tag changes do not conflict but merge is not requested' do
+        sign_in_as(member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        current_tag = Tag.find_or_create_by_tag_name!('current_added_tag', category: :general)
+        PostTag.create!(post: post_record, tag: current_tag, created_user: member)
+
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: post_record.title,
+            tags: "spec_tag #{Tag.no_deerjikist.name} incoming_added_tag")
+
+        expect(response).to have_http_status(:conflict)
+
+        expect(json.fetch('mergeable')).to be(true)
+
+        tag_change = json.fetch('changes').find { |change| change.fetch('field') == 'tag_names' }
+        expect(tag_change).to be_present
+        expect(tag_change.fetch('conflict')).to be(false)
+        expect(tag_change.fetch('added_by_current')).to include('current_added_tag')
+        expect(tag_change.fetch('added_by_me')).to include('incoming_added_tag')
+      end
+
+      it 'merges non-conflicting stale tag changes when merge is true' do
+        sign_in_as(member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        current_tag = Tag.find_or_create_by_tag_name!('current_merge_tag', category: :general)
+        PostTag.create!(post: post_record, tag: current_tag, created_user: member)
+
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: post_record.title,
+            tags: "spec_tag #{Tag.no_deerjikist.name} incoming_merge_tag",
+            merge: '1')
+
+        expect(response).to have_http_status(:ok)
+
+        names = post_record.reload.tags.map(&:name)
+
+        expect(names).to include('spec_tag')
+        expect(names).to include(Tag.no_deerjikist.name)
+        expect(names).to include('current_merge_tag')
+        expect(names).to include('incoming_merge_tag')
+      end
+
+      it 'does not conflict when only nico tags changed after the base version' do
+        sign_in_as(member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        nico_tag = create_nico_tag!('nico:optimistic_lock_nico')
+        PostTag.create!(post: post_record, tag: nico_tag, created_user: member)
+
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+        expect(post_record.reload.version_no).to eq(2)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: post_record.title,
+            tags: "spec_tag #{ Tag.no_deerjikist.name }")
+
+        expect(response).to have_http_status(:ok)
+
+        names = post_record.reload.tags.map(&:name)
+
+        expect(names).to include('spec_tag')
+        expect(names).to include(Tag.no_deerjikist.name)
+        expect(names).to include(nico_tag.name)
+      end
+
+      it 'keeps nico tags even when they are not included in PUT tags' do
+        sign_in_as(member)
+
+        nico_tag = create_nico_tag!('nico:readonly_update_nico')
+        PostTag.create!(post: post_record, tag: nico_tag, created_user: member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: 'updated title',
+            tags: "spec_tag #{ Tag.no_deerjikist.name }")
+
+        expect(response).to have_http_status(:ok)
+
+        names = post_record.reload.tags.map(&:name)
+
+        expect(names).to include('spec_tag')
+        expect(names).to include(Tag.no_deerjikist.name)
+        expect(names).to include(nico_tag.name)
+      end
+
+      it 'allows non-nico tags linked from nico tags to be removed by normal post update' do
+        sign_in_as(member)
+
+        nico_tag = create_nico_tag!('nico:relation_source')
+        linked_tag = Tag.find_or_create_by_tag_name!('relation_linked_tag', category: :general)
+
+        NicoTagRelation.create!(nico_tag:, tag: linked_tag)
+        PostTag.create!(post: post_record, tag: nico_tag, created_user: member)
+        PostTag.create!(post: post_record, tag: linked_tag, created_user: member)
+
+        base_version = create_post_version_for!(post_record.reload)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
+            title: post_record.title,
+            tags: "spec_tag #{ Tag.no_deerjikist.name }")
+
+        expect(response).to have_http_status(:ok)
+
+        names = post_record.reload.tags.map(&:name)
+
+        expect(names).to include(nico_tag.name)
+        expect(names).to include('spec_tag')
+        expect(names).to include(Tag.no_deerjikist.name)
+        expect(names).not_to include(linked_tag.name)
+      end
+
+      it 'force-updates stale posts without base_version_no' do
+        sign_in_as(member)
+
+        create_post_version_for!(post_record.reload)
+
+        post_record.update!(title: 'updated by other user')
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+        put "/posts/#{post_record.id}", params: post_write_params(
+            title: 'forced title',
+            tags: "spec_tag #{Tag.no_deerjikist.name}",
+            force: '1')
+
+        expect(response).to have_http_status(:ok)
+        expect(post_record.reload.title).to eq('forced title')
+      end
+    end
   end
 
   describe 'GET /posts/random' do
@@ -1434,13 +1675,14 @@ RSpec.describe 'Posts API', type: :request do
 
     it 'creates next version on PUT /posts/:id when snapshot changes' do
       sign_in_as(member)
-      create_post_version_for!(post_record)
+      base_version = create_post_version_for!(post_record)
 
       tag_name2 = TagName.create!(name: 'spec_tag_2')
       Tag.create!(tag_name: tag_name2, category: :general)
 
       expect do
         put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
             title: 'updated title',
             tags: 'spec_tag_2')
       end.to change(PostVersion, :count).by(1)
@@ -1459,13 +1701,15 @@ RSpec.describe 'Posts API', type: :request do
       sign_in_as(member)
 
       PostTag.create!(post: post_record, tag: Tag.no_deerjikist)
-      create_post_version_for!(post_record.reload)
+      base_version = create_post_version_for!(post_record.reload)
 
       expect {
         put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
             title: post_record.title,
             tags: 'spec_tag')
       }.not_to change(PostVersion, :count)
+
       expect(response).to have_http_status(:ok)
 
       version = post_record.reload.post_versions.order(:version_no).last
@@ -1490,10 +1734,11 @@ RSpec.describe 'Posts API', type: :request do
 
     it 'does not create a version when PUT /posts/:id is invalid' do
       sign_in_as(member)
-      create_post_version_for!(post_record)
+      base_version = create_post_version_for!(post_record)
 
       expect do
         put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
             title: 'updated title',
             tags: 'spec_tag',
             original_created_from: Time.zone.local(2020, 1, 2, 0, 0, 0).iso8601,
@@ -1507,46 +1752,22 @@ RSpec.describe 'Posts API', type: :request do
   describe 'tag versioning from post write actions' do
     let(:member) { create(:user, :member) }
 
-    it 'creates tag snapshot for normalised tags on POST /posts' do
-      sign_in_as(member)
-
-      expect {
-        post '/posts', params: post_write_params(
-            title: 'tag versioned post',
-            url: 'https://example.com/tag-versioned-post',
-            tags: 'spec_tag',
-            thumbnail: dummy_upload)
-      }.to change { tag.reload.tag_versions.count }.by(1)
-
-      expect(response).to have_http_status(:created)
-
-      version = tag.reload.tag_versions.order(:version_no).last
-      expect(version.version_no).to eq(1)
-      expect(version.event_type).to eq('create')
-      expect(version.name).to eq('spec_tag')
-      expect(version.category).to eq('general')
-      expect(version.created_by_user_id).to eq(member.id)
-    end
-
     it 'creates tag snapshot for normalised tags on PUT /posts/:id' do
       sign_in_as(member)
 
+      base_version = create_post_version_for!(post_record.reload)
+
       tag_name2 = TagName.create!(name: 'spec_tag_2')
       tag2 = Tag.create!(tag_name: tag_name2, category: :general)
 
       expect {
         put "/posts/#{post_record.id}", params: post_write_params(
+            base_version_no: base_version.version_no,
             title: 'updated title',
             tags: 'spec_tag_2')
       }.to change { tag2.reload.tag_versions.count }.by(1)
 
-      expect(response).to have_http_status(:ok)
+      expect(response).to have_http_status(:ok), response.body
-
-      version = tag2.reload.tag_versions.order(:version_no).last
-      expect(version.version_no).to eq(1)
-      expect(version.event_type).to eq('create')
-      expect(version.name).to eq('spec_tag_2')
-      expect(version.created_by_user_id).to eq(member.id)
     end
   end
 end

backend/spec/requests/tag_versions_spec.rb

@@ -26,6 +26,7 @@ RSpec.describe 'TagVersions API', type: :request do
     created_by_user:,
     created_at:
   )
+    version =
         TagVersion.create!(
             tag: tag,
             version_no: version_no,
@@ -35,8 +36,12 @@ RSpec.describe 'TagVersions API', type: :request do
             aliases: Array(aliases).join(' '),
             parent_tag_ids: Array(parent_tags).map(&:id).join(' '),
             created_by_user: created_by_user,
-      created_at: created_at
+            created_at: created_at)
-    )
+
+    tag.update_columns(version_no: version_no) if tag.has_attribute?(:version_no)
+    tag.version_no = version_no if tag.respond_to?(:version_no=)
+
+    version
   end
 
   let!(:v1) do

backend/spec/services/version_recorder_spec.rb

@@ -0,0 +1,85 @@
+require 'rails_helper'
+
+RSpec.describe VersionRecorder do
+  let(:member) { create(:user, :member) }
+
+  let(:post_record) do
+    Post.create!(
+        title: 'version recorder post',
+        url: 'https://example.com/version-recorder-post')
+  end
+
+  it 'updates record version_no when creating the first version' do
+    version =
+        PostVersionRecorder.record!(
+            post: post_record,
+            event_type: :create,
+            created_by_user: member)
+
+    expect(version.version_no).to eq(1)
+    expect(post_record.reload.version_no).to eq(1)
+  end
+
+  it 'updates record version_no when creating the next version' do
+    PostVersionRecorder.record!(
+        post: post_record,
+        event_type: :create,
+        created_by_user: member)
+
+    post_record.update!(title: 'updated version recorder post')
+
+    version =
+        PostVersionRecorder.record!(
+            post: post_record.reload,
+            event_type: :update,
+            created_by_user: member)
+
+    expect(version.version_no).to eq(2)
+    expect(post_record.reload.version_no).to eq(2)
+  end
+
+  it 'does not create a new version or advance version_no when snapshot is unchanged' do
+    first =
+        PostVersionRecorder.record!(
+            post: post_record,
+            event_type: :create,
+            created_by_user: member)
+
+    expect {
+      version =
+          PostVersionRecorder.record!(
+              post: post_record.reload,
+              event_type: :update,
+              created_by_user: member)
+
+      expect(version).to eq(first)
+    }.not_to change(PostVersion, :count)
+
+    expect(post_record.reload.version_no).to eq(1)
+  end
+
+  it 'raises when record version_no is older than the latest version' do
+    PostVersionRecorder.record!(
+        post: post_record,
+        event_type: :create,
+        created_by_user: member)
+
+    post_record.update!(title: 'updated once')
+
+    PostVersionRecorder.record!(
+        post: post_record.reload,
+        event_type: :update,
+        created_by_user: member)
+
+    post_record.update_columns(version_no: 1)
+
+    post_record.update!(title: 'updated with stale version_no')
+
+    expect {
+      PostVersionRecorder.record!(
+          post: post_record.reload,
+          event_type: :update,
+          created_by_user: member)
+    }.to raise_error(RuntimeError, /version_no/)
+  end
+end

docs/codex-handoff.md

@@ -0,0 +1,646 @@
+# Codex handoff for BTRC Hub / タグ広場
+
+This document transfers project-specific context from prior ChatGPT-assisted design and review work to Codex.
+
+Use this file as project background.
+Use `AGENTS.md`, `backend/AGENTS.md`, and `frontend/AGENTS.md` for concrete coding rules and verification commands.
+
+## Project identity
+
+BTRC Hub / タグ広場 is a collaborative knowledge base for collecting, tagging, explaining, and rediscovering Bocchi the Rock creature-related works.
+
+It is not a generic SNS.
+It is not a comment board.
+It is not a service for rehosting external content.
+It is primarily a structured link, tag, wiki, material, and viewing-party system.
+
+Core domains:
+
+1. Posts
+2. Tags
+3. Wiki pages
+4. Materials
+5. Theatre / watch-party features
+
+The project is already publicly accessible and indexed by search engines, but it has not been broadly announced. Treat it as a small public production system, not a private prototype.
+
+## Current stack
+
+Backend:
+
+- Ruby 3.2.2
+- Rails 8.0.2 API
+- MySQL 8
+- Active Storage
+- Cloudflare R2 / S3-compatible storage is expected for uploaded files
+- RSpec
+
+Frontend:
+
+- React 19.1
+- Vite 6.3
+- TypeScript 5.8
+- Axios
+- TanStack Query
+- Tailwind CSS
+- Framer Motion
+- shadcn-like local components
+- react-markdown
+- react-markdown-editor-lite
+- remark-wiki-autolink
+
+Batch / background-like tasks:
+
+- Rake tasks
+- Nico sync
+- YouTube sync
+- Similarity calculation tasks
+
+## Repository working principle
+
+Before editing, inspect the existing implementation.
+
+Do not invent a new architecture when the current repo already has an established convention.
+
+Keep changes scoped to the requested issue.
+
+Prefer small, reviewable changes over broad rewrites.
+
+Do not perform unrelated cleanup in the same patch.
+
+When a task has design ambiguity, first produce a short investigation and recommended plan. Do not silently choose a risky design.
+
+## User coding preferences
+
+General:
+
+- Prefer single quotes for strings unless interpolation, escaping, or framework convention makes double quotes better.
+- Do not add production dependencies without explicit approval.
+- Do not perform broad formatting churn.
+- Do not convert unrelated files to a different style.
+
+Ruby:
+
+- Do not put a space before method-call parentheses.
+- Do not use `%w`.
+- Do not use `%i`.
+- Keep Rails code idiomatic, but preserve the user's style where the repo already uses it.
+
+TypeScript / Python:
+
+- The user prefers GNU-style spacing before parentheses where syntactically valid.
+- Preserve existing project formatting if a formatter or nearby code dictates otherwise.
+
+## Current authentication model
+
+The system does not use normal email/password authentication.
+
+Users are authenticated by inheritance code.
+
+Frontend:
+
+- Stores the code in `localStorage.user_code`.
+- Sends it as the `X-Transfer-Code` header.
+
+Backend:
+
+- Looks up `users.inheritance_code`.
+- Sets `current_user`.
+
+Roles:
+
+- `guest`
+- `member`
+- `admin`
+
+Important helper:
+
+- `User#gte_member?` returns true for `member` and `admin`.
+
+Never introduce a conventional login assumption unless the issue explicitly asks for it.
+
+## BAN / abuse-control model
+
+The backend currently enforces BAN at API level.
+
+The relevant before_action order is conceptually:
+
+1. Reject banned IP address.
+2. Authenticate user if transfer code exists.
+3. Reject banned user.
+
+Entities:
+
+- `users.banned_at`
+- `ip_addresses.banned_at`
+- `user_ips`
+
+IP addresses are stored as binary values using `IPAddr#hton`.
+
+Do not weaken BAN behavior.
+
+Do not move BAN checks behind optional authentication.
+
+Do not make preview, theatre, verify, user creation, or public-looking endpoints bypass BAN without an explicit design decision.
+
+## Public-operation assumptions
+
+Current practical operation:
+
+- A few editor accounts exist.
+- Meaningful editing is mostly done by the owner.
+- Read access is already public.
+- Search engines have indexed the site.
+- Future editor applications are expected through Discord.
+- Prospective editors are likely people known in the Bocchi creature community.
+
+This means security and moderation issues matter even if traffic is still small.
+
+## Core domain summary
+
+### Posts
+
+Posts are external URL-based link records.
+
+Important properties:
+
+- `url` is required and unique.
+- URLs are normalized.
+- Only HTTP / HTTPS are allowed.
+- Posts can have thumbnails through Active Storage.
+- `uploaded_user_id` may be NULL for synced or bot-created posts.
+- `original_created_from` and `original_created_before` represent a time range for original content creation.
+- When both original time bounds exist, `from < before` is required.
+
+Parent/child posts:
+
+- Current implementation uses `post_implications`.
+- It is many-to-many.
+- Do not assume `posts.parent_id`.
+- Frontend/API clients must send `parent_post_ids`, even when empty.
+- `parent_post_ids` is parsed as a space-separated ID string.
+- Self-parenting is invalid.
+- Missing parent IDs are invalid.
+
+Versions:
+
+- `post_versions` stores snapshots.
+- `version_no` is a per-post sequence.
+- Snapshot includes title, URL, thumbnail base, tags, parent post IDs, original time bounds, event type, and actor.
+- Optimistic locking for posts is planned / important, but do not assume it is fully implemented unless the code proves it.
+
+### Tags
+
+Tags are central.
+
+There is separation between tag names and tag entities:
+
+- `tag_names`
+- `tags`
+
+Categories:
+
+- `deerjikist`
+- `meme`
+- `character`
+- `general`
+- `material`
+- `nico`
+- `meta`
+
+Alias model:
+
+- `tag_names.canonical_id` expresses aliases.
+- `canonical_id = NULL` means canonical name.
+- `canonical_id != NULL` means alias.
+- An alias must not point to another alias.
+- A tag name that already has a tag or wiki page generally must not be aliasified.
+
+Tag normalization:
+
+- User-entered tags are normalized through existing backend logic.
+- Known aliases are canonicalized.
+- Parent tags are expanded recursively.
+- `nico:` is normally rejected for manual entry.
+- Special tags such as tag-request / bot / unknown-deerjikist / video / niconico / youtube must be protected.
+
+Do not casually change tag normalization, alias resolution, or parent expansion. These affect search, wiki, sync, and historical data.
+
+### Nico tags
+
+Nico tags use the `nico` category and have separate versioning.
+
+Important relation:
+
+- `nico_tag_relations` maps external Nico tags to internal tags.
+- `nico_tag_id` must be a Nico category tag.
+- `tag_id` must not be Nico category.
+
+Do not allow ordinary manual tag editing to create or corrupt Nico tags.
+
+### Deerjikists
+
+Deerjikists map external platform identities to internal `deerjikist` tags.
+
+Known platforms include:
+
+- `nico`
+- `youtube`
+
+YouTube handles may be normalized to `UC...` channel IDs.
+
+Do not treat user-facing handles and canonical channel IDs as interchangeable without checking existing code.
+
+### Wiki
+
+Wiki pages are a major knowledge layer.
+
+Important points:
+
+- Wiki pages are tied to tag-like titles.
+- Title handling, aliases, and canonical tag names matter.
+- There is line-level storage / revision-oriented behavior in the current implementation.
+- There has been design tension between wiki revisions and wiki versions.
+- Wiki conflict detection using `base_revision_id` exists on the backend side.
+- Frontend support for conflict detection must be verified before assuming it is complete.
+
+Do not redesign Wiki storage casually.
+
+Do not add a second competing history system.
+
+Do not break existing wiki URLs.
+
+### Materials
+
+Materials connect files or reference URLs to `material` or `character` tags.
+
+Important properties:
+
+- A material has a `tag_id`.
+- The tag must be `material` or `character`.
+- A material requires either `url` or attached `file`.
+- Active Storage is involved.
+- Upload/security policy matters more than plain link posting.
+
+Important unresolved/risky area:
+
+- Material creation permissions have historically been risky because upload endpoints can be abused.
+- Prefer `member` or higher for material creation unless the issue explicitly says otherwise.
+
+### Theatre
+
+Theatre is an experimental watch-party style feature.
+
+Known pieces include:
+
+- Display
+- Presence
+- Next post
+- Comments
+- Host-like control
+
+Do not assume theatre has complete CRUD/admin support unless the code proves it.
+
+Theatre may become expensive if next-item selection uses random DB ordering.
+
+## Current high-risk areas
+
+Treat these areas with extra care.
+
+### Security
+
+- Preview API SSRF protection.
+- External iframe / embed CSP.
+- Markdown link safety.
+- BAN / IP BAN bypass.
+- Transfer-code leakage.
+- Guest write access.
+- Upload endpoints.
+- Admin-only tag operations.
+- System tag mutation.
+
+### Data integrity
+
+- Tag alias canonicalization.
+- Tag parent expansion.
+- Post parent many-to-many relationships.
+- Version tables.
+- `version_no` synchronization.
+- Schema drift from branch migration contamination.
+- Wiki revision/version split.
+- Material version recording.
+
+### Frontend correctness
+
+- React Hooks must not be called conditionally.
+- Role guards are currently spread across components/pages.
+- TanStack Query keys must not collide between ID/name or ID/title variants.
+- URL path segments containing tag names or wiki titles must use `encodeURIComponent`.
+- API response types may allow `null` users for bot or migration data.
+- Tag autocomplete has had duplicated logic and stale state hazards.
+
+### Performance
+
+- Avoid unbounded `limit`.
+- Avoid `order('RAND()')` for growing tables.
+- Avoid loading full relations just to count.
+- Avoid Ruby-side sorting/paging for large histories.
+- Tag sidebar client-side aggregation can become expensive.
+- Wiki full-text search needs deliberate indexing/design.
+
+## Current priority order
+
+Use this as the default priority unless an issue says otherwise.
+
+### P0: Safety before broad announcement
+
+1. Preview API SSRF hardening.
+2. Material creation permission tightening.
+3. System tag mutation holes.
+4. `GET /users/me` transfer-code leakage through query params.
+5. Limit caps for index/history/comment APIs.
+6. CSP / iframe sandbox policy.
+7. Confirm BAN enforcement remains global.
+
+### P1: Core correctness
+
+1. Post optimistic locking with `version_no`.
+2. Wiki edit conflict handling.
+3. Wiki history/revision model clarification.
+4. Wiki search truthfulness: implement body search or remove false UI.
+5. Tag alias/canonical/wiki interaction.
+6. Tag URL encoding.
+7. TanStack Query key separation.
+8. Frontend null-user handling.
+9. React Hooks rule fixes.
+10. Material version policy.
+
+### P2: Operational/admin usability
+
+1. Admin screens for users, IPs, bans, aliases, and settings.
+2. Settings table and user settings usage.
+3. Better tag sidebar.
+4. Better role guard helpers.
+5. Better frontend tests.
+6. Better issue triage and closure of already-implemented issues.
+
+### P3: Future features
+
+1. Theatre list/create/edit/admin flow.
+2. Muted/hidden tags.
+3. Tag category custom colors.
+4. Responsive refinements.
+5. Watch-party improvements.
+6. Broader embed support.
+
+## Known issue triage notes
+
+Some existing issues may already be partially or mostly implemented.
+
+Before implementing an issue, check code first.
+
+Examples:
+
+- Tag search and OR/NOT search may already be mostly implemented.
+- BAN enforcement may have been implemented after earlier issue drafts.
+- YouTube sync exists and should not be treated as purely planned.
+- Parent posts are many-to-many in current schema, even if older issues mention one-to-many.
+- Some issues may reflect old schema or old branch state.
+
+When in doubt:
+
+1. Inspect current code.
+2. Inspect schema.
+3. Inspect routes.
+4. Inspect frontend usage.
+5. Report whether the issue is implemented, partially implemented, not implemented, or obsolete.
+6. Only then edit.
+
+## Verification expectations
+
+Backend changes:
+
+- Run RSpec when possible.
+- Add request specs for API behavior changes.
+- Add model specs for validation / normalization changes.
+- Check migrations and schema consistency.
+- Do not silently ignore pending migrations.
+
+Frontend changes:
+
+- Run build.
+- Run lint if configured.
+- Run tests if configured.
+- Add tests for important behavior when the test framework exists.
+- If frontend tests are not yet installed, state that clearly.
+
+Full-stack changes:
+
+- Verify both backend and frontend compile/test paths where possible.
+- Confirm API response shapes match TypeScript types.
+- Confirm authorization behavior on both server and UI.
+
+If commands cannot be run because dependencies are missing, report that explicitly. Do not pretend verification passed.
+
+## Branch / migration caution
+
+The project has previously suffered from schema contamination caused by running migrations from another branch.
+
+Be careful when touching:
+
+- `db/schema.rb`
+- migration files
+- parent post schema
+- banned / banned_at schema
+- version_no migrations
+- wiki asset schema
+
+Before changing migrations:
+
+1. Inspect current schema.
+2. Inspect existing migrations.
+3. Confirm whether the intended branch already includes related migrations.
+4. Prefer additive migrations for shared branches.
+5. Do not edit already-applied production migrations unless explicitly instructed.
+
+## API design principles
+
+Prefer explicit server-side authorization.
+
+Do not rely only on frontend hiding.
+
+Do not return sensitive codes unnecessarily.
+
+Use 403 for authorization failures.
+
+Use 422 for validation failures.
+
+Use 409 for edit conflicts.
+
+Do not expose internal exception messages to users.
+
+Clamp or reject abusive limits consistently.
+
+Keep response shape stable unless the issue explicitly includes a breaking API change.
+
+## Frontend design principles
+
+Use existing route and query-key conventions.
+
+Use TanStack Query `enabled` rather than conditional hook calls.
+
+Do not let role-based early returns change hook order.
+
+Centralize repeated tag autocomplete logic when touching it.
+
+Use `encodeURIComponent` for tag names and wiki titles in URL path segments.
+
+Prefer graceful fallback for nullable actors:
+
+- bot operation
+- deleted user
+- migration-created data
+- external sync
+
+Do not assume all API user fields are non-null.
+
+## Testing priorities to add over time
+
+Frontend tests are especially important because the backend already has more mature RSpec coverage.
+
+Suggested first frontend tests:
+
+1. Tag autocomplete.
+2. Post form tag editing.
+3. Tag URL encoding.
+4. Wiki edit conflict UI.
+5. Role guard behavior.
+6. Null-user history rendering.
+7. Dialog behavior.
+8. Top navigation responsive behavior.
+
+Backend test priorities:
+
+1. BAN enforcement across public-looking endpoints.
+2. Material permissions.
+3. Preview SSRF rejection.
+4. System tag protection.
+5. Post optimistic locking.
+6. Wiki conflict detection.
+7. Tag alias/canonical behavior.
+8. Limit caps.
+9. Parent post parsing.
+10. Version recorder behavior.
+
+## What Codex should not do without explicit approval
+
+Do not:
+
+- Replace Rails.
+- Replace React.
+- Replace TanStack Query.
+- Redesign the database.
+- Rewrite Wiki storage.
+- Remove version tables.
+- Change authentication model.
+- Change role names.
+- Change tag category names.
+- Add background job infrastructure.
+- Add a new UI framework.
+- Add a new test framework if one already exists.
+- Add major dependencies.
+- Change public URL design.
+- Change production storage configuration.
+- Remove historical data behavior.
+- Simplify BAN/security checks.
+- Treat the site as private-only.
+
+## Good first Codex tasks
+
+Start with investigation-only tasks.
+
+Example:
+
+```txt
+Inspect the repository and summarize the Rails, React, TypeScript, and test setup.
+Do not modify files.
+List commands that actually exist in this repository.
+List risks Codex should know before editing.
+```
+
+Then small safe patches:
+
+```txt
+Fix a React Hooks rule violation in one file.
+Keep behavior unchanged.
+Run the relevant frontend verification commands.
+```
+
+```txt
+Add encodeURIComponent around one tag-name URL path segment.
+Add or update a test if the project has a frontend test setup.
+Run build/lint.
+```
+
+```txt
+Add a request spec for a known authorization rule.
+Do not change implementation unless the spec fails for the expected reason.
+```
+
+Avoid starting with:
+
+- Wiki history redesign.
+- Post versioning redesign.
+- Full admin screen suite.
+- Broad frontend refactor.
+- Database cleanup.
+- Authentication rewrite.
+
+## Relationship with ChatGPT
+
+ChatGPT has been used for:
+
+- Design review.
+- Risk analysis.
+- Prioritization.
+- Specification reconstruction.
+- Migration/locking discussions.
+- Codex migration planning.
+
+Codex should be used mainly for:
+
+- Repository inspection.
+- Localized implementation.
+- Test addition.
+- Running verification commands.
+- Producing small reviewable diffs.
+
+For ambiguous architecture, Codex should stop and present options rather than implement a guessed design.
+
+## Current strategic stance
+
+The project should not be rewritten from scratch.
+
+The current Rails + React system is acceptable.
+
+The immediate goal is not elegance.
+The immediate goal is safe public operation, data integrity, and maintainable incremental improvement.
+
+Priority is:
+
+1. Prevent abuse/security incidents.
+2. Preserve data correctness.
+3. Make editing safe for multiple users.
+4. Add tests around fragile frontend behavior.
+5. Improve admin/operation workflows.
+6. Optimize performance after obvious dangerous patterns are removed.
+
+## Final rule
+
+When current code, old specs, issue drafts, and memory disagree, current code wins.
+
+When current code is unsafe, write that explicitly and propose a small safe fix.
+
+When the task is too broad, split it.
+
+When verification cannot be performed, say exactly what was not verified.

docs/commands.md

@@ -0,0 +1,30 @@
+# Commands
+
+## Backend
+
+```sh
+cd backend
+bundle install
+bundle exec rails db:migrate
+bundle exec rspec
+bundle exec rails routes
+```
+
+## Frontend
+
+```sh
+cd frontend
+npm install
+npm run dev
+npm run build
+npm run lint
+npm run test
+npm run test:run
+```
+
+### Full verification
+
+```sh
+cd backend && bundle exec rspec
+cd ../frontend && npm run test:run && npm run build && npm run lint
+```

docs/issue-workflow.md

@@ -0,0 +1,80 @@
+# Issue workflow
+
+## Source of truth
+
+Gitea Issues are the source of truth for tasks, discussions, labels, milestones, and status.
+
+Do not copy the full backlog into git.
+
+Repository documents may define:
+
+- issue templates
+- triage rules
+- Codex task format
+- verification rules
+- release checklist
+
+## Labels
+
+Recommended labels:
+
+- `P0`
+- `P1`
+- `P2`
+- `P3`
+- `security`
+- `data-integrity`
+- `backend`
+- `frontend`
+- `wiki`
+- `tags`
+- `materials`
+- `theatre`
+- `codex-ready`
+- `needs-design`
+- `blocked`
+- `good-first-codex-task`
+
+## Codex-ready criteria
+
+An issue can be labeled `codex-ready` only when it has:
+
+- clear background
+- target area
+- concrete tasks
+- acceptance criteria
+- verification commands
+- explicit non-goals
+- no unresolved architecture decision
+
+## Workflow
+
+1. Create or refine the issue in Gitea.
+2. Add labels and milestone.
+3. If design is unclear, label `needs-design`.
+4. Discuss design before implementation.
+5. When scoped enough, label `codex-ready`.
+6. Give Codex the issue URL or copied issue body.
+7. Codex creates a branch.
+8. Codex implements a small patch.
+9. Codex runs verification commands.
+10. Human reviews the diff.
+11. Merge.
+12. Close the issue from the PR/commit message.
+
+## Commit message
+
+Use issue references when possible:
+
+```txt
+fix: prevent preview SSRF
+
+Refs: #123
+```
+or
+```
+fix: prevent preview SSRF
+
+Closes: #123
+```
+depending on whether the change fully resolves the issue.

docs/release-checklist.md

@@ -0,0 +1,8 @@
+# Release checklist
+
+- [ ] Backend specs pass
+- [ ] Frontend build passes
+- [ ] No pending migrations
+- [ ] Preview API SSRF checked
+- [ ] BAN behavior checked
+- [ ] CSP checked

docs/roadmap.md

@@ -0,0 +1,8 @@
+# Roadmap
+
+## Public announcement readiness
+
+- Harden preview API
+- Tighten material creation permission
+- Add admin MVP
+- Improve frontend tests

frontend/AGENTS.md

@@ -0,0 +1,95 @@
+# frontend/AGENTS.md
+
+## Scope
+
+These rules apply to work under `frontend/`.
+
+This is a Vite + React + TypeScript app using TanStack Query, Tailwind CSS, Framer Motion, Radix UI-style components, MDX, and Zustand.
+
+## Commands
+
+Use only scripts that exist in `package.json`:
+
+```sh
+npm run dev
+npm run build
+npm run lint
+npm run preview
+```
+
+`npm run build` runs `tsc -b && vite build`, and `postbuild` runs `node scripts/generate-sitemap.js`.
+
+There is currently no `test` script in `package.json`. Do not run or report `npm test` unless a test script is added.
+
+After frontend changes, run:
+
+```sh
+npm run build
+npm run lint
+```
+
+If either command cannot be run or fails, report the exact command and failure.
+
+## TypeScript
+
+- TypeScript is strict. `tsconfig.app.json` enables `strict`, `noUnusedLocals`, `noUnusedParameters`, `erasableSyntaxOnly`, `noFallthroughCasesInSwitch`, and `noUncheckedSideEffectImports`.
+- Keep types explicit at module boundaries, API helpers, and exported utilities.
+- Use `import type` for type-only imports.
+- Prefer existing shared types from `src/types.ts` before adding local duplicate types.
+- Preserve the repository's existing spacing style in TypeScript, including GNU-style spacing before call parentheses where it is already used.
+- Prefer single quotes for strings unless interpolation or escaping makes double quotes better.
+
+## React
+
+- Use function components.
+- Existing page components commonly export an anonymous function satisfying `FC`; match nearby file style when editing.
+- React hooks must be called unconditionally and at the top level of components or custom hooks.
+- Keep page-level components under `src/pages`.
+- Keep shared and feature components under `src/components`.
+- Use `react-router-dom` route params and navigation patterns already present in `src/App.tsx`.
+- Encode URL path-segment values with `encodeURIComponent`.
+
+## TanStack Query
+
+- Use `@tanstack/react-query` for server state.
+- Query keys should come from `src/lib/queryKeys.ts`; add key builders there instead of using ad hoc arrays in components.
+- Fetch functions should live in domain helpers under `src/lib`, such as `posts.ts`, `tags.ts`, or `wiki.ts`.
+- Use `useQueryClient().invalidateQueries` with the shared root keys when mutations affect cached lists or detail views.
+- The app-wide `QueryClient` is configured in `src/main.tsx`; do not create additional clients in feature code.
+
+## API calls
+
+- Use `src/lib/api.ts` for HTTP calls.
+- The API wrapper attaches `X-Transfer-Code` from `localStorage` and converts non-blob responses to camelCase.
+- Send Rails snake_case params and request body keys where the backend expects them.
+- Do not bypass the API wrapper unless there is a specific reason, such as a third-party request outside the Rails API.
+- For blob responses, pass `responseType: 'blob'` so the wrapper does not camelCase the body.
+
+## Imports and aliases
+
+- The `@` alias points to `frontend/src`.
+- Prefer `@/...` imports for app code instead of long relative paths.
+- Keep type imports separate with `import type`.
+- Match existing import grouping: external packages, app modules, then type imports.
+
+## Tailwind and UI
+
+- Tailwind scans `src/**/*.{html,js,ts,jsx,tsx,mdx}`.
+- Use `cn` from `src/lib/utils.ts` for conditional class names and class merging.
+- Reuse components from `src/components/common`, `src/components/layout`, and `src/components/ui` before adding new primitives.
+- Keep Tailwind classes consistent with nearby components.
+- When adding dynamic tag color classes, update `tailwind.config.js` safelist if the class cannot be statically detected.
+- Do not introduce new UI libraries or production dependencies without approval.
+
+## Lint and build constraints
+
+- ESLint uses `@eslint/js`, `typescript-eslint`, `eslint-plugin-react-hooks`, and `eslint-plugin-react-refresh`.
+- The hooks rules are enforced; fix hook ordering instead of disabling the rule.
+- `react-refresh/only-export-components` is enabled as a warning with `allowConstantExport`.
+- Build failures from unused locals or unused parameters are TypeScript errors, not lint-only issues.
+
+## Files to avoid in routine work
+
+- Do not edit `dist/` output directly.
+- Do not inspect or modify `node_modules/` unless explicitly needed.
+- Keep generated build artifacts out of source changes unless the user asks for them.

frontend/eslint.config.js

@@ -5,7 +5,7 @@ import reactRefresh from 'eslint-plugin-react-refresh'
 import tseslint from 'typescript-eslint'
 
 export default tseslint.config(
-  { ignores: ['dist'] },
+  { ignores: ['dist', 'tailwind.config.js'] },
   {
     extends: [js.configs.recommended, ...tseslint.configs.recommended],
     files: ['**/*.{ts,tsx}'],

frontend/package.json

@@ -8,6 +8,8 @@
     "build": "tsc -b && vite build",
     "postbuild": "node scripts/generate-sitemap.js",
     "lint": "eslint .",
+    "test": "vitest",
+    "test:run": "vitest run",
     "preview": "vite preview"
   },
   "dependencies": {
@@ -45,6 +47,10 @@
   "devDependencies": {
     "@eslint/js": "^9.25.0",
     "@tailwindcss/typography": "^0.5.19",
+    "@testing-library/dom": "^10.4.1",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
+    "@testing-library/user-event": "^14.6.1",
     "@types/axios": "^0.14.4",
     "@types/markdown-it": "^14.1.2",
     "@types/mdx": "^2.0.13",
@@ -58,11 +64,13 @@
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.19",
     "globals": "^16.0.0",
+    "jsdom": "^26.1.0",
     "postcss": "^8.5.3",
     "tailwindcss": "^3.4.13",
     "typescript": "~5.8.3",
     "typescript-eslint": "^8.30.1",
-    "vite": "^6.3.5"
+    "vite": "^6.3.5",
+    "vitest": "^4.1.5"
   },
   "description": "This template provides a minimal setup to get React working in Vite with HMR and some ESLint rules.",
   "main": "eslint.config.js",

frontend/src/App.tsx

@@ -93,7 +93,7 @@ const PostDetailRoute = ({ user }: { user: User | null }) => {
 }
 
 
-export default (() => {
+const App: FC = () => {
   const [user, setUser] = useState<User | null> (null)
   const [status, setStatus] = useState (200)
 
@@ -156,4 +156,6 @@ export default (() => {
 	  </DialogueProvider>
 	</BrowserRouter>
       </>)
-}) satisfies FC
+}
+
+export default App

frontend/src/components/DraggableDroppableTagRow.tsx

@@ -19,7 +19,7 @@ type Props = {
     sp?:              boolean }
 
 
-export default (({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }: Props) => {
+const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }) => {
   const dndId = `tag-node:${ pathKey }`
 
   const downPosRef = useRef<{ x: number; y: number } | null> (null)
@@ -96,4 +96,6 @@ export default (({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }:
 	  <TagLink tag={tag} nestLevel={nestLevel}/>
 	</motion.div>
       </div>)
-}) satisfies FC<Props>
+}
+
+export default DraggableDroppableTagRow

frontend/src/components/ErrorScreen.test.tsx

@@ -0,0 +1,32 @@
+import { render, screen } from '@testing-library/react'
+import { HelmetProvider } from 'react-helmet-async'
+import { describe, expect, it } from 'vitest'
+
+import ErrorScreen from '@/components/ErrorScreen'
+
+describe ('ErrorScreen', () => {
+  it.each ([
+    [403, '権限ないよ（笑）'],
+    [404, 'ページないよ（笑）'],
+    [500, '鯖でエラー出たって（嘲笑）'],
+    [503, '鯖死んでるよ（泣）'],
+  ]) ('renders status %s', (status, message) => {
+    render (
+        <HelmetProvider>
+          <ErrorScreen status={status}/>
+        </HelmetProvider>,
+    )
+
+    expect (screen.getByText (String (status))).toBeInTheDocument ()
+    expect (screen.getByText (message)).toBeInTheDocument ()
+    expect (screen.getByAltText ('逃げたギター')).toBeInTheDocument ()
+  })
+
+  it ('throws for unsupported statuses', () => {
+    expect (() => render (
+        <HelmetProvider>
+          <ErrorScreen status={418}/>
+        </HelmetProvider>,
+    )).toThrow ()
+  })
+})

frontend/src/components/ErrorScreen.tsx

@@ -10,7 +10,7 @@ import type { FC } from 'react'
 type Props = { status: number }
 
 
-export default (({ status }: Props) => {
+const ErrorScreen: FC<Props> = ({ status }) => {
   const [message, rightMsg, leftMsg]: [string, string, string] = (() => {
     switch (status)
     {
@@ -58,4 +58,6 @@ export default (({ status }: Props) => {
 	  <p className="mr-[-.5em]">{message}</p>
 	</div>
       </MainArea>)
-}) satisfies FC<Props>
+}
+
+export default ErrorScreen

frontend/src/components/MaterialSidebar.tsx

@@ -31,7 +31,7 @@ const setChildrenById = (
     }))
 
 
-export default (() => {
+const MaterialSidebar: FC = () => {
   const [tags, setTags] = useState<TagWithDepth[]> ([])
   const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
   const [tagFetchedFlags, setTagFetchedFlags] = useState<Record<number, boolean>> ({ })
@@ -94,4 +94,6 @@ export default (() => {
 	  {renderTags (tags)}
 	</ul>
       </SidebarComponent>)
-}) satisfies FC
+}
+
+export default MaterialSidebar

frontend/src/components/MenuSeparator.tsx

@@ -1,9 +1,11 @@
 import type { FC } from 'react'
 
 
-export default (() => (
+const MenuSeparator: FC = () => (
     <>
       <span className="hidden md:inline flex items-center px-2">|</span>
       <hr className="block md:hidden w-full opacity-25
 		     border-t border-black dark:border-white"/>
-    </>)) satisfies FC
+    </>)
+
+export default MenuSeparator

frontend/src/components/PostEditForm.test.tsx

@@ -0,0 +1,69 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import PostEditForm from '@/components/PostEditForm'
+import { buildPost, buildTag } from '@/test/factories'
+
+const postsApi = vi.hoisted (() => ({
+  updatePost: vi.fn (),
+}))
+
+const api = vi.hoisted (() => ({
+  isApiError: vi.fn (() => false),
+}))
+
+const toastApi = vi.hoisted (() => ({
+  toast: vi.fn (),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/components/ui/use-toast', () => toastApi)
+vi.mock ('@/components/dialogues/DialogueProvider', () => ({
+  useDialogue: () => ({
+    choice: vi.fn (),
+  }),
+}))
+
+describe ('PostEditForm', () => {
+  it ('submits edited post fields with the current base version', async () => {
+    const onSave = vi.fn ()
+    const post = buildPost ({
+      id:        8,
+      versionNo: 4,
+      title:     'old',
+      tags:      [
+        buildTag ({ name: 'general-tag', category: 'general' }),
+        buildTag ({ id: 2, name: 'nico-tag', category: 'nico' }),
+      ],
+      parentPosts: [buildPost ({ id: 2, title: 'parent' })],
+    })
+    postsApi.updatePost.mockResolvedValueOnce ({
+      ...post,
+      versionNo: 5,
+      title:     'new',
+      tags:      [buildTag ({ name: 'new-tag' })],
+    })
+
+    render (<PostEditForm post={post} onSave={onSave}/>)
+
+    const [title, parentIds] = screen.getAllByRole ('textbox')
+    fireEvent.change (title, { target: { value: 'new' } })
+    fireEvent.change (parentIds, { target: { value: '3 4' } })
+    fireEvent.submit (screen.getByRole ('button', { name: '更新' }).closest ('form')!)
+
+    await waitFor (() => {
+      expect (postsApi.updatePost).toHaveBeenCalledWith (
+          expect.objectContaining ({
+            id:            8,
+            title:         'new',
+            parentPostIds: '3 4',
+            tags:          'general-tag',
+          }),
+          { baseVersionNo: 4 },
+      )
+    })
+    expect (onSave).toHaveBeenCalledWith (expect.objectContaining ({ versionNo: 5 }))
+    expect (toastApi.toast).toHaveBeenCalledWith ({ description: '更新しました．' })
+  })
+})

frontend/src/components/PostEditForm.tsx

@@ -6,25 +6,30 @@ import Label from '@/components/common/Label'
 import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
+import { isApiError } from '@/lib/api'
 import { updatePost } from '@/lib/posts'
+import { msToTime } from '@/lib/utils'
 
 import type { FC, FormEvent } from 'react'
 
-import type { Post, Tag } from '@/types'
+import type { Post, TagWithSections } from '@/types'
 
 
-const tagsToStr = (tags: Tag[]): string => {
+const tagsToStr = (tags: TagWithSections[]): string => {
-  const result: Tag[] = []
+  const result: Omit<TagWithSections, 'children'>[] = []
 
-  const walk = (tag: Tag) => {
+  const walk = (tag: TagWithSections) => {
     const { children, ...rest } = tag
     result.push (rest)
-    children?.forEach (walk)
+    children.forEach (walk)
   }
 
   tags.filter (t => t.category !== 'nico').forEach (walk)
 
-  return [...(new Set (result.map (t => t.name)))].join (' ')
+  return [...(new Set (result.map (t =>
+      `${ t.name }${ t.sections
+		     .map (s => `[${ msToTime (s.beginMs) }-${ msToTime (s.endMs) }]`)
+		     .join ('') }`)))].join (' ')
 }
 
 
@@ -32,7 +37,7 @@ type Props = { post:    Post
 	       onSave:  (newPost: Post) => void }
 
 
-export default (({ post, onSave }: Props) => {
+const PostEditForm: FC<Props> = ({ post, onSave }) => {
   const [disabled, setDisabled] = useState (false)
   const [originalCreatedBefore, setOriginalCreatedBefore] =
       useState<string | null> (post.originalCreatedBefore)
@@ -62,7 +67,7 @@ export default (({ post, onSave }: Props) => {
     }
     catch (e)
     {
-      const response = (e as any)?.response
+      const response = isApiError<{ mergeable?: boolean }> (e) ? e.response : undefined
 
       if (response?.status !== 409)
 	{
@@ -103,18 +108,24 @@ export default (({ post, onSave }: Props) => {
     e.preventDefault ()
 
     setDisabled (true)
+    try
+    {
       await update ({ id: post.id, title, tags, parentPostIds,
 		      originalCreatedFrom, originalCreatedBefore },
 		    { baseVersionNo: post.versionNo })
+    }
+    finally
+    {
       setDisabled (false)
     }
+  }
 
   useEffect (() => {
-    setTags(tagsToStr (post.tags))
+    setTags (tagsToStr (post.tags))
   }, [post])
 
   return (
-      <div className="max-w-xl pt-2 space-y-4">
+      <form onSubmit={handleSubmit} className="max-w-xl pt-2 space-y-4">
 	{/* タイトル */}
 	<div>
 	  <Label>タイトル</Label>
@@ -154,10 +165,10 @@ export default (({ post, onSave }: Props) => {
 	{/* 送信 */}
 	<Button
 	    type="submit"
-	    disabled={disabled}
+	    disabled={disabled}>
-	    onClick={handleSubmit}
-	    className="px-4 py-2 bg-blue-600 text-white rounded disabled:bg-gray-400">
 	  更新
 	</Button>
-      </div>)
+      </form>)
-}) satisfies FC<Props>
+}
+
+export default PostEditForm

frontend/src/components/PostEmbed.test.tsx

@@ -0,0 +1,63 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import PostEmbed from '@/components/PostEmbed'
+import { buildPost } from '@/test/factories'
+
+const dialogue = vi.hoisted (() => ({
+  confirm: vi.fn (),
+}))
+
+vi.mock ('@/components/dialogues/DialogueProvider', () => ({
+  useDialogue: () => dialogue,
+}))
+
+vi.mock ('@/components/NicoViewer', () => ({
+  default: ({ id }: { id: string }) => <div>Nico:{id}</div>,
+}))
+
+vi.mock ('react-youtube', () => ({
+  default: ({ videoId }: { videoId: string }) => <div>YouTube:{videoId}</div>,
+}))
+
+describe ('PostEmbed', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('embeds nicovideo watch URLs', () => {
+    render (<PostEmbed post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}/>)
+
+    expect (screen.getByText ('Nico:sm12345')).toBeInTheDocument ()
+  })
+
+  it ('embeds x/twitter status URLs', () => {
+    render (<PostEmbed post={buildPost ({ url: 'https://x.com/someone/status/12345' })}/>)
+
+    expect (screen.getByRole ('link', { name: '@someone' })).toBeInTheDocument ()
+  })
+
+  it ('embeds youtube watch URLs', () => {
+    render (<PostEmbed post={buildPost ({ url: 'https://www.youtube.com/watch?v=abc123' })}/>)
+
+    expect (screen.getByText ('YouTube:abc123')).toBeInTheDocument ()
+  })
+
+  it ('asks before framing unknown external pages', async () => {
+    dialogue.confirm.mockResolvedValueOnce (true)
+    render (
+        <PostEmbed
+            post={buildPost ({ url: 'https://example.com/page', title: 'external' })}/>,
+    )
+
+    fireEvent.click (screen.getByRole ('link', { name: '外部ページを表示' }))
+
+    await waitFor (() => {
+      expect (dialogue.confirm).toHaveBeenCalled ()
+    })
+    expect (await screen.findByTitle ('external')).toHaveAttribute (
+        'src',
+        'https://example.com/page',
+    )
+  })
+})

frontend/src/components/PostEmbed.tsx

@@ -3,6 +3,7 @@ import YoutubeEmbed from 'react-youtube'
 
 import NicoViewer from '@/components/NicoViewer'
 import TwitterEmbed from '@/components/TwitterEmbed'
+import { useDialogue } from '@/components/dialogues/DialogueProvider'
 
 import type { FC, RefObject } from 'react'
 
@@ -15,7 +16,10 @@ type Props = {
     onMetadataChange?:  (meta: NiconicoMetadata) => void }
 
 
-export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
+const PostEmbed: FC<Props> = ({ ref, post, onLoadComplete, onMetadataChange }) => {
+  const dialogue = useDialogue ()
+  const [framed, setFramed] = useState (false)
+
   const url = new URL (post.url)
 
   switch (url.hostname.split ('.').slice (-2).join ('.'))
@@ -41,7 +45,7 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
   case 'twitter.com':
   case 'x.com':
     {
-      const mUserId = url.pathname.match (/(?<=\/)[^\/]+?(?=\/|$|\?)/)
+      const mUserId = url.pathname.match (/(?<=\/)[^/]+?(?=\/|$|\?)/)
       const mStatusId = url.pathname.match (/(?<=\/status\/)\d+?(?=\/|$|\?)/)
       if (!(mUserId) || !(mStatusId))
 	break
@@ -69,8 +73,6 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
     }
   }
 
-  const [framed, setFramed] = useState (false)
-
   return (
       <>
 	{framed
@@ -82,15 +84,22 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
 		height={360}/>)
 	 : (
 	    <div>
-	      <a href="#" onClick={e => {
+	      <a href="#" onClick={async e => {
 		e.preventDefault ()
-		setFramed (confirm ('未確認の外部ページを表示します。\n'
+
-				    + '悪意のあるスクリプトが実行される可能性があります。\n'
+		setFramed (await dialogue.confirm ({
-				    + '表示しますか?'))
+		    title: '未確認の外部ページを表示します。',
-		return
+		    description: (
+			<div>
+			  <p>悪意のあるスクリプトが実行される可能性があります。</p>
+			  <p>表示しますか?</p>
+			</div>),
+		    confirmText: '表示' }))
 	      }}>
 		外部ページを表示
 	      </a>
 	    </div>)}
       </>)
-}) satisfies FC<Props>
+}
+
+export default PostEmbed

frontend/src/components/PostFormTagsArea.test.tsx

@@ -0,0 +1,34 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import PostFormTagsArea from '@/components/PostFormTagsArea'
+import { buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('PostFormTagsArea', () => {
+  it ('updates text and fetches autocomplete for the selected token', async () => {
+    const setTags = vi.fn ()
+    api.apiGet.mockResolvedValueOnce ([buildTag ({ name: '虹夏', postCount: 3 })])
+
+    renderWithProviders (<PostFormTagsArea tags="虹" setTags={setTags}/>)
+
+    const textarea = screen.getByRole ('textbox')
+    fireEvent.focus (textarea)
+    fireEvent.select (textarea, { target: { selectionStart: 1, selectionEnd: 1 } })
+    fireEvent.change (textarea, { target: { value: '虹夏' } })
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenCalledWith (
+          '/tags/autocomplete',
+          { params: { q: '虹', nico: '0' } },
+      )
+    })
+    expect (setTags).toHaveBeenCalledWith ('虹夏')
+  })
+})

frontend/src/components/PostFormTagsArea.tsx

@@ -31,13 +31,12 @@ const replaceToken = (value: string, start: number, end: number, text: string) =
     `${ value.slice (0, start) }${ text }${ value.slice (end) }`
 
 
-type Props =
+type Props = Omit<ComponentPropsWithoutRef<'textarea'>, 'value' | 'onChange' | 'onBlur'> & {
-    & { tags:     string
+    tags:     string
     setTags:  (tags: string) => void }
-    & ComponentPropsWithoutRef<'textarea'>
 
 
-export default (({ tags, setTags, ...rest }: Props) => {
+const PostFormTagsArea: FC<Props> = ({ tags, setTags, ...rest }) => {
   const ref = useRef<HTMLTextAreaElement> (null)
 
   const [bounds, setBounds] = useState<{ start: number; end: number }> ({ start: 0, end: 0 })
@@ -77,6 +76,7 @@ export default (({ tags, setTags, ...rest }: Props) => {
       <div className="relative w-full">
 	<Label>タグ</Label>
 	<TextArea
+	    {...rest}
 	    ref={ref}
 	    value={tags}
 	    onChange={ev => setTags (ev.target.value)}
@@ -88,8 +88,7 @@ export default (({ tags, setTags, ...rest }: Props) => {
 	    onBlur={() => {
 	      setFocused (false)
 	      setSuggestionsVsbl (false)
-	    }}
+	    }}/>
-	    {...rest}/>
 	{focused && (
 	    <TagSearchBox
 		suggestions={suggestionsVsbl && suggestions.length > 0
@@ -98,4 +97,6 @@ export default (({ tags, setTags, ...rest }: Props) => {
 		activeIndex={-1}
 		onSelect={handleTagSelect}/>)}
       </div>)
-}) satisfies FC<Props>
+}
+
+export default PostFormTagsArea

frontend/src/components/PostList.test.tsx

@@ -0,0 +1,44 @@
+import { fireEvent, screen } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import PostList from '@/components/PostList'
+import { buildPost } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const prefetchers = vi.hoisted (() => ({
+  prefetchForURL: vi.fn (),
+}))
+
+vi.mock ('@/lib/prefetchers', () => prefetchers)
+
+describe ('PostList', () => {
+  beforeEach (() => {
+    prefetchers.prefetchForURL.mockResolvedValue (undefined)
+  })
+
+  it ('renders post thumbnails as links to post details', () => {
+    renderWithProviders (
+        <PostList posts={[
+          buildPost ({ id: 1, title: 'First', thumbnail: 'first.jpg' }),
+          buildPost ({ id: 2, title: null, url: 'https://example.com/second' }),
+        ]}/>,
+    )
+
+    expect (screen.getByRole ('link', { name: 'First' })).toHaveAttribute (
+        'href',
+        '/posts/1',
+    )
+    expect (
+        screen.getByRole ('link', { name: 'https://example.com/second' }),
+    ).toHaveAttribute ('href', '/posts/2')
+  })
+
+  it ('calls the optional click handler', () => {
+    const onClick = vi.fn ()
+    renderWithProviders (<PostList posts={[buildPost ()]} onClick={onClick}/>)
+
+    fireEvent.click (screen.getByRole ('link', { name: 'テスト投稿' }))
+
+    expect (onClick).toHaveBeenCalledTimes (1)
+  })
+})

frontend/src/components/PostList.tsx

@@ -14,7 +14,7 @@ type Props = { posts:     Post[]
 	       onClick?:  (event: MouseEvent<HTMLElement>) => void }
 
 
-export default (({ posts, onClick }: Props) => {
+const PostList: FC<Props> = ({ posts, onClick }) => {
   const location = useLocation ()
 
   const setForLocationKey = useSharedTransitionStore (s => s.setForLocationKey)
@@ -42,7 +42,7 @@ export default (({ posts, onClick }: Props) => {
 		    layoutId={layoutId}
 		    className={cn ('w-full h-full overflow-hidden rounded-xl shadow',
 				   'transform-gpu will-change-transform',
-				   (post.childPosts ?? []).length > 0 && 'outline-4 outline-green-500',
+				   (post.childPosts ?? []).length > 0 && 'ring-4 ring-green-500',
 				   (post.parentPosts ?? []).length > 0 && 'ring-4 ring-yellow-500')}
 		    whileHover={{ scale: 1.02 }}
 		    onLayoutAnimationStart={() => {
@@ -70,4 +70,6 @@ export default (({ posts, onClick }: Props) => {
 	      </PrefetchLink>)
 	})}
       </div>)
-}) satisfies FC<Props>
+}
+
+export default PostList

frontend/src/components/PostOriginalCreatedTimeField.test.tsx

@@ -0,0 +1,63 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeField'
+
+describe ('PostOriginalCreatedTimeField', () => {
+  it ('updates from and before values', () => {
+    const setFrom = vi.fn ()
+    const setBefore = vi.fn ()
+
+    render (
+        <PostOriginalCreatedTimeField
+            originalCreatedFrom={null}
+            setOriginalCreatedFrom={setFrom}
+            originalCreatedBefore={null}
+            setOriginalCreatedBefore={setBefore}/>,
+    )
+
+    const inputs = screen.getAllByDisplayValue ('')
+    fireEvent.change (inputs[0], { target: { value: '2026-01-02T03:04' } })
+    fireEvent.change (inputs[1], { target: { value: '2026-01-03T03:04' } })
+
+    expect (setFrom).toHaveBeenCalledWith (expect.any (String))
+    expect (setBefore).toHaveBeenCalledWith (expect.any (String))
+  })
+
+  it ('infers an exclusive before value on blur', () => {
+    const setBefore = vi.fn ()
+
+    render (
+        <PostOriginalCreatedTimeField
+            originalCreatedFrom={null}
+            setOriginalCreatedFrom={vi.fn ()}
+            originalCreatedBefore={null}
+            setOriginalCreatedBefore={setBefore}/>,
+    )
+
+    const input = screen.getAllByDisplayValue ('')[0]
+    fireEvent.blur (input, { target: { value: '2026-01-02T03:04' } })
+
+    expect (setBefore).toHaveBeenCalledWith (expect.any (String))
+  })
+
+  it ('resets both values', () => {
+    const setFrom = vi.fn ()
+    const setBefore = vi.fn ()
+
+    render (
+        <PostOriginalCreatedTimeField
+            originalCreatedFrom="2026-01-01T00:00:00Z"
+            setOriginalCreatedFrom={setFrom}
+            originalCreatedBefore="2026-01-02T00:00:00Z"
+            setOriginalCreatedBefore={setBefore}/>,
+    )
+
+    const buttons = screen.getAllByRole ('button', { name: 'リセット' })
+    fireEvent.click (buttons[0])
+    fireEvent.click (buttons[1])
+
+    expect (setFrom).toHaveBeenCalledWith (null)
+    expect (setBefore).toHaveBeenCalledWith (null)
+  })
+})

frontend/src/components/PostOriginalCreatedTimeField.tsx

@@ -12,11 +12,11 @@ type Props = {
     setOriginalCreatedBefore: (x: string | null) => void }
 
 
-export default (({ disabled,
+const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
 		   originalCreatedFrom,
 		   setOriginalCreatedFrom,
 		   originalCreatedBefore,
-		   setOriginalCreatedBefore }: Props) => (
+		   setOriginalCreatedBefore }) => (
     <div>
       <Label>オリジナルの作成日時</Label>
       <div className="my-1 flex">
@@ -71,4 +71,6 @@ export default (({ disabled,
 	  </Button>
 	</div>
       </div>
-    </div>)) satisfies FC<Props>
+    </div>)
+
+export default PostOriginalCreatedTimeField

frontend/src/components/RouteBlockerOverlay.test.tsx

@@ -0,0 +1,30 @@
+import { render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, it } from 'vitest'
+
+import RouteBlockerOverlay, { useOverlayStore } from '@/components/RouteBlockerOverlay'
+
+describe ('RouteBlockerOverlay', () => {
+  afterEach (() => {
+    useOverlayStore.setState ({ active: false })
+    document.body.style.overflow = ''
+    document.body.removeAttribute ('aria-busy')
+  })
+
+  it ('renders nothing while inactive', () => {
+    useOverlayStore.setState ({ active: false })
+
+    const { container } = render (<RouteBlockerOverlay/>)
+
+    expect (container).toBeEmptyDOMElement ()
+  })
+
+  it ('renders a blocking progressbar and marks the body busy while active', () => {
+    useOverlayStore.setState ({ active: true })
+
+    render (<RouteBlockerOverlay/>)
+
+    expect (screen.getByRole ('progressbar', { name: 'Loading' })).toBeInTheDocument ()
+    expect (document.body).toHaveAttribute ('aria-busy', 'true')
+    expect (document.body.style.overflow).toBe ('hidden')
+  })
+})

frontend/src/components/RouteBlockerOverlay.tsx

@@ -13,7 +13,7 @@ export const useOverlayStore = create<OverlayStore> (set => ({
     setActive:  v => set ({ active: v }) }))
 
 
-export default (() => {
+const RouteBlockerOverlay: FC = () => {
   const active = useOverlayStore (s => s.active)
 
   useEffect (() => {
@@ -43,4 +43,6 @@ export default (() => {
 	  </div>
 	</div>
       </div>)
-}) satisfies FC
+}
+
+export default RouteBlockerOverlay

frontend/src/components/SortHeader.test.tsx

@@ -0,0 +1,39 @@
+import { screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import SortHeader from '@/components/SortHeader'
+import { renderWithProviders } from '@/test/render'
+
+describe ('SortHeader', () => {
+  it ('toggles the active sort direction and resets the page', () => {
+    renderWithProviders (
+        <SortHeader
+            by="title"
+            label="タイトル"
+            currentOrder="title:asc"
+            defaultDirection={{ title: 'asc' }}/>,
+        { route: '/posts?tags=x&page=4&order=title%3Aasc' },
+    )
+
+    expect (screen.getByRole ('link', { name: 'タイトル ▲' })).toHaveAttribute (
+        'href',
+        '/posts?tags=x&page=1&order=title%3Adesc',
+    )
+  })
+
+  it ('uses default direction for inactive fields', () => {
+    renderWithProviders (
+        <SortHeader
+            by="updated_at"
+            label="更新"
+            currentOrder="title:desc"
+            defaultDirection={{ title: 'asc', updated_at: 'desc' }}/>,
+        { route: '/posts?page=2' },
+    )
+
+    expect (screen.getByRole ('link', { name: '更新' })).toHaveAttribute (
+        'href',
+        '/posts?page=1&order=updated_at%3Adesc',
+    )
+  })
+})

frontend/src/components/TagDetailSidebar.tsx

@@ -26,13 +26,13 @@ import { dateString, originalCreatedAtString } from '@/lib/utils'
 import type { DragEndEvent } from '@dnd-kit/core'
 import type { FC, MutableRefObject, ReactNode } from 'react'
 
-import type { Category, Post, Tag } from '@/types'
+import type { Category, Post, TagWithSections } from '@/types'
 
-type TagByCategory = { [key in Category]: Tag[] }
+type TagByCategory = { [key in Category]: TagWithSections[] }
 
 
 const renderTagTree = (
-    tag:              Tag,
+    tag:              TagWithSections,
     nestLevel:        number,
     path:             string,
     suppressClickRef: MutableRefObject<boolean>,
@@ -63,7 +63,7 @@ const renderTagTree = (
 
 
 const isDescendant = (
-    root:     Tag,
+    root:     TagWithSections,
     targetId: number,
 ): boolean => {
   if (!(root.children))
@@ -84,8 +84,8 @@ const isDescendant = (
 const findTag = (
     byCat:  TagByCategory,
     id:     number,
-): Tag | undefined => {
+): TagWithSections | undefined => {
-  const walk = (nodes: Tag[]): Tag | undefined => {
+  const walk = (nodes: TagWithSections[]): TagWithSections | undefined => {
     for (const t of nodes)
       {
 	if (t.id === id)
@@ -151,7 +151,7 @@ const DropSlot = ({ cat }: { cat: Category }) => {
 type Props = { post: Post; sp?: boolean }
 
 
-export default (({ post, sp }: Props) => {
+const TagDetailSidebar: FC<Props> = ({ post, sp }) => {
   sp = Boolean (sp)
 
   const qc = useQueryClient ()
@@ -167,7 +167,7 @@ export default (({ post, sp }: Props) => {
       }
 
     for (const cat of Object.keys (tagsTmp) as (keyof typeof tagsTmp)[])
-      tagsTmp[cat].sort ((tagA: Tag, tagB: Tag) => tagA.name < tagB.name ? -1 : 1)
+      tagsTmp[cat].sort ((tagA: TagWithSections, tagB: TagWithSections) => tagA.name < tagB.name ? -1 : 1)
 
     return tagsTmp
   }, [post])
@@ -376,4 +376,6 @@ export default (({ post, sp }: Props) => {
 	  </DragOverlay>
 	</DndContext>
       </SidebarComponent>)
-}) satisfies FC<Props>
+}
+
+export default TagDetailSidebar

frontend/src/components/TagLink.test.tsx

@@ -0,0 +1,45 @@
+import { screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import TagLink from '@/components/TagLink'
+import { buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+describe ('TagLink', () => {
+  it ('links tag names to post search and shows counts', () => {
+    renderWithProviders (
+        <TagLink tag={buildTag ({ name: '虹 夏', postCount: 4 })}/>,
+    )
+
+    expect (screen.getByRole ('link', { name: '虹 夏' })).toHaveAttribute (
+        'href',
+        '/posts?tags=%E8%99%B9+%E5%A4%8F',
+    )
+    expect (screen.getByText ('4')).toBeInTheDocument ()
+  })
+
+  it ('links wiki markers to the correct detail route', () => {
+    renderWithProviders (
+        <TagLink tag={buildTag ({ hasWiki: true, name: 'a/b' })}/>,
+    )
+
+    expect (screen.getByRole ('link', { name: '?' })).toHaveAttribute (
+        'href',
+        '/wiki/a%2Fb',
+    )
+  })
+
+  it ('renders aliases and non-link tags when requested', () => {
+    renderWithProviders (
+        <TagLink
+            tag={buildTag ({ matchedAlias: '別名', name: '正式名' })}
+            linkFlg={false}
+            withWiki={false}
+            withCount={false}/>,
+    )
+
+    expect (screen.getByText ('別名')).toBeInTheDocument ()
+    expect (screen.getByText ('正式名')).toBeInTheDocument ()
+    expect (screen.queryByRole ('link')).not.toBeInTheDocument ()
+  })
+})

frontend/src/components/TagLink.tsx

@@ -27,12 +27,12 @@ type Props =
     | PropsWithoutLink
 
 
-export default (({ tag,
+const TagLink: FC<Props> = ({ tag,
 		   nestLevel = 0,
 		   linkFlg   = true,
 		   withWiki  = true,
 		   withCount = true,
-		   ...props }: Props) => {
+		   ...props }) => {
   const spanClass = cn (
       `text-${ TAG_COLOUR[tag.category] }-${ LIGHT_COLOUR_SHADE }`,
       `dark:text-${ TAG_COLOUR[tag.category] }-${ DARK_COLOUR_SHADE }`)
@@ -126,4 +126,6 @@ export default (({ tag,
 	{withCount && (
 	    <span className="ml-1">{tag.postCount}</span>)}
       </>)
-}) satisfies FC<Props>
+}
+
+export default TagLink

frontend/src/components/TagSearch.tsx

@@ -12,7 +12,7 @@ import type { ChangeEvent, FC, KeyboardEvent } from 'react'
 import type { Tag } from '@/types'
 
 
-export default (() => {
+const TagSearch: FC = () => {
   const location = useLocation ()
   const navigate = useNavigate ()
 
@@ -115,4 +115,6 @@ export default (() => {
 		      activeIndex={activeIndex}
 		      onSelect={handleTagSelect}/>
       </div>)
-}) satisfies FC
+}
+
+export default TagSearch

frontend/src/components/TagSearchBox.test.tsx

@@ -0,0 +1,30 @@
+import { fireEvent, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import TagSearchBox from '@/components/TagSearchBox'
+import { buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+describe ('TagSearchBox', () => {
+  it ('renders suggestions and selects tags on mouse down', () => {
+    const handleSelect = vi.fn ()
+    const tag = buildTag ({ id: 9, name: '候補', postCount: 2 })
+
+    renderWithProviders (
+        <TagSearchBox suggestions={[tag]} activeIndex={0} onSelect={handleSelect}/>,
+    )
+
+    fireEvent.mouseDown (screen.getByText ('候補'))
+
+    expect (handleSelect).toHaveBeenCalledWith (tag)
+    expect (screen.getByText ('2')).toBeInTheDocument ()
+  })
+
+  it ('renders nothing when suggestions are empty', () => {
+    const { container } = renderWithProviders (
+        <TagSearchBox suggestions={[]} activeIndex={-1} onSelect={vi.fn ()}/>,
+    )
+
+    expect (container).toBeEmptyDOMElement ()
+  })
+})

frontend/src/components/TagSearchBox.tsx

@@ -10,7 +10,7 @@ type Props = { suggestions: Tag[]
 	       onSelect:    (tag: Tag) => void }
 
 
-export default (({ suggestions, activeIndex, onSelect }: Props) => {
+const TagSearchBox: FC<Props> = ({ suggestions, activeIndex, onSelect }) => {
   if (suggestions.length === 0)
     return
 
@@ -26,4 +26,6 @@ export default (({ suggestions, activeIndex, onSelect }: Props) => {
 	      <TagLink tag={tag} linkFlg={false} withWiki={false}/>
 	    </li>))}
       </ul>)
-}) satisfies FC<Props>
+}
+
+export default TagSearchBox

frontend/src/components/TagSidebar.tsx

@@ -19,7 +19,7 @@ type Props = { posts:     Post[]
 	       onClick?:  (event: MouseEvent<HTMLElement>) => void }
 
 
-export default (({ posts, onClick }: Props) => {
+const TagSidebar: FC<Props> = ({ posts, onClick }) => {
   const navigate = useNavigate ()
 
   const [tagsVsbl, setTagsVsbl] = useState (false)
@@ -126,4 +126,6 @@ export default (({ posts, onClick }: Props) => {
 	  {tagsVsbl ? '▲▲▲ タグ一覧を閉じる ▲▲▲' : '▼▼▼ タグ一覧を表示 ▼▼▼'}
 	</a>
       </SidebarComponent>)
-}) satisfies FC<Props>
+}
+
+export default TagSidebar

frontend/src/components/TopNav.tsx

@@ -26,7 +26,7 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
     pathName: string }): Menu => {
   const postCount = tag?.postCount ?? 0
 
-  const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^\/]+/.test (pathName) && wikiId)
+  const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^/]+/.test (pathName) && wikiId)
   const wikiTitle = pathName.split ('/')[2] ?? ''
 
   const tagFlg = /^\/tags\/\d+/.test (pathName)
@@ -80,7 +80,7 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 }
 
 
-export default (({ user }: Props) => {
+const TopNav: FC<Props> = ({ user }) => {
   const location = useLocation ()
 
   const dirRef = useRef<(-1) | 1> (1)
@@ -159,12 +159,12 @@ export default (({ user }: Props) => {
   useEffect (() => {
     const unsubscribe = WikiIdBus.subscribe (setWikiId)
     return () => unsubscribe ()
-  }, [activeIdx])
+  }, [])
 
   useEffect (() => {
     setMenuOpen (false)
     setOpenItemIdx (activeIdx)
-  }, [location])
+  }, [activeIdx, location])
 
   return (
       <>
@@ -433,4 +433,6 @@ export default (({ user }: Props) => {
 	      </motion.div>)}
 	</AnimatePresence>
       </>)
-}) satisfies FC<Props>
+}
+
+export default TopNav

frontend/src/components/TopNavUser.test.tsx

@@ -0,0 +1,29 @@
+import { screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import TopNavUser from '@/components/TopNavUser'
+import { buildUser } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+describe ('TopNavUser', () => {
+  it ('renders nothing without a user', () => {
+    const { container } = renderWithProviders (<TopNavUser user={null}/>)
+
+    expect (container).toBeEmptyDOMElement ()
+  })
+
+  it ('links named users to settings', () => {
+    renderWithProviders (<TopNavUser user={buildUser ({ name: '山田' })}/>)
+
+    expect (screen.getByRole ('link', { name: '山田' })).toHaveAttribute (
+        'href',
+        '/users/settings',
+    )
+  })
+
+  it ('uses the anonymous display name', () => {
+    renderWithProviders (<TopNavUser user={buildUser ({ name: null })}/>)
+
+    expect (screen.getByRole ('link', { name: '名もなきニジラー' })).toBeInTheDocument ()
+  })
+})

frontend/src/components/TopNavUser.tsx

@@ -10,7 +10,7 @@ type Props = { user:  User | null,
 	       sp?:   boolean }
 
 
-export default (({ user, sp }: Props) => {
+const TopNavUser: FC<Props> = ({ user, sp }) => {
   if (!(user))
     return
 
@@ -28,4 +28,6 @@ export default (({ user, sp }: Props) => {
 	  {user.name || '名もなきニジラー'}
 	</PrefetchLink>
       </>)
-}) satisfies FC<Props>
+}
+
+export default TopNavUser

frontend/src/components/TwitterEmbed.test.tsx

@@ -0,0 +1,19 @@
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import TwitterEmbed from '@/components/TwitterEmbed'
+
+describe ('TwitterEmbed', () => {
+  it ('renders tweet and user links', () => {
+    render (<TwitterEmbed userId="user_name" statusId="12345"/>)
+
+    expect (screen.getByRole ('link', { name: '@user_name' })).toHaveAttribute (
+        'href',
+        'https://twitter.com/user_name?ref_src=twsrc%3Etfw',
+    )
+    expect (screen.getByRole ('link', { name: /\d/ })).toHaveAttribute (
+        'href',
+        'https://twitter.com/user_name/status/12345?ref_src=twsrc%5Etfw',
+    )
+  })
+})

frontend/src/components/TwitterEmbed.tsx

@@ -5,7 +5,7 @@ type Props = {
     statusId: string }
 
 
-export default (({ userId, statusId }: Props) => {
+const TwitterEmbed: FC<Props> = ({ userId, statusId }) => {
   const now = (new Date).toLocaleDateString ()
 
   return (
@@ -18,4 +18,6 @@ export default (({ userId, statusId }: Props) => {
 	</blockquote>
 	<script async src="https://platform.twitter.com/widgets.js" charSet="utf-8"/>
       </div>)
-}) satisfies FC<Props>
+}
+
+export default TwitterEmbed

frontend/src/components/WikiBody.tsx

@@ -25,7 +25,7 @@ const mdComponents = { a: (({ href, children }) => (
 				  </a>))) } as const satisfies Components
 
 
-export default (({ title, body }: Props) => {
+const WikiBody: FC<Props> = ({ title, body }) => {
   const { data } = useQuery ({
       enabled: Boolean (body),
       queryKey: wikiKeys.index ({ }),
@@ -39,4 +39,6 @@ export default (({ title, body }: Props) => {
       <ReactMarkdown components={mdComponents} remarkPlugins={remarkPlugins}>
 	{body || `このページは存在しません。[新規作成してください](/wiki/new?title=${ encodeURIComponent (title) })。`}
       </ReactMarkdown>)
-}) satisfies FC<Props>
+}
+
+export default WikiBody

frontend/src/components/common/DateTimeField.test.tsx

@@ -0,0 +1,27 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import DateTimeField from '@/components/common/DateTimeField'
+
+describe ('DateTimeField', () => {
+  it ('renders an ISO value as a datetime-local value', () => {
+    render (<DateTimeField aria-label="日時" value="2026-01-02T03:04:05.000Z"/>)
+
+    const input = screen.getByLabelText ('日時')
+
+    expect (input).toHaveValue ('2026-01-02T12:04')
+  })
+
+  it ('reports local changes as ISO strings and empty values as null', () => {
+    const handleChange = vi.fn ()
+    render (<DateTimeField aria-label="日時" onChange={handleChange}/>)
+
+    const input = screen.getByLabelText ('日時')
+    fireEvent.change (input, { target: { value: '2026-01-02T03:04' } })
+    fireEvent.change (input, { target: { value: '' } })
+
+    const first = handleChange.mock.calls[0]?.[0]
+    expect (new Date (first).getFullYear ()).toBe (2026)
+    expect (handleChange).toHaveBeenLastCalledWith (null)
+  })
+})

frontend/src/components/common/DateTimeField.tsx

@@ -25,7 +25,7 @@ type Props = Omit<ComponentPropsWithoutRef<'input'>, 'onChange'> & {
     onBlur?:    (ev: FocusEvent<HTMLInputElement>) => void }
 
 
-export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
+const DateTimeField: FC<Props> = ({ value, onChange, className, onBlur, ...rest }) => {
   const [local, setLocal] = useState ('')
 
   useEffect (() => {
@@ -34,6 +34,7 @@ export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
 
   return (
       <input
+	  {...rest}
 	  className={cn ('border rounded p-2', className)}
 	  type="datetime-local"
 	  value={local}
@@ -42,6 +43,7 @@ export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
 	    setLocal (v)
 	    onChange?.(v ? (new Date (v)).toISOString () : null)
 	  }}
-	  onBlur={onBlur}
+	  onBlur={onBlur}/>)
-	  {...rest}/>)
+}
-}) satisfies FC<Props>
+
+export default DateTimeField

frontend/src/components/common/Form.tsx

@@ -3,7 +3,9 @@ import type { FC, ReactNode } from 'react'
 type Props = { children: ReactNode }
 
 
-export default (({ children }: Props) => (
+const Form: FC<Props> = ({ children }) => (
     <div className="max-w-xl mx-auto p-4 space-y-4">
       {children}
-    </div>)) satisfies FC<Props>
+    </div>)
+
+export default Form

frontend/src/components/common/Label.test.tsx

@@ -0,0 +1,26 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import Label from '@/components/common/Label'
+
+describe ('Label', () => {
+  it ('renders a plain label', () => {
+    render (<Label>名前</Label>)
+
+    expect (screen.getByText ('名前')).toBeInTheDocument ()
+  })
+
+  it ('renders and toggles the optional checkbox', () => {
+    const handleChange = vi.fn ()
+
+    render (
+        <Label checkBox={{ label: '不明', checked: false, onChange: handleChange }}>
+          日時
+        </Label>,
+    )
+
+    fireEvent.click (screen.getByRole ('checkbox', { name: '不明' }))
+
+    expect (handleChange).toHaveBeenCalledTimes (1)
+  })
+})

frontend/src/components/common/Label.tsx

@@ -1,12 +1,14 @@
 import React from 'react'
 
+import type { FC } from 'react'
+
 type Props = { children:  React.ReactNode
                checkBox?: { label:    string
                             checked:  boolean
                             onChange: (event: React.ChangeEvent<HTMLInputElement>) => void } }
 
 
-export default ({ children, checkBox }: Props) => {
+const Label: FC<Props> = ({ children, checkBox }) => {
   if (!(checkBox))
     {
       return (
@@ -26,3 +28,5 @@ export default ({ children, checkBox }: Props) => {
         </label>
       </div>)
 }
+
+export default Label

frontend/src/components/common/PageTitle.test.tsx

@@ -0,0 +1,15 @@
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import PageTitle from '@/components/common/PageTitle'
+
+
+describe ('PageTitle', () => {
+  it ('renders children as a level 1 heading', () => {
+    render (<PageTitle>Test title</PageTitle>)
+
+    const heading = screen.getByRole ('heading', { level: 1 })
+
+    expect (heading.textContent).toBe ('Test title')
+  })
+})

frontend/src/components/common/PageTitle.tsx

@@ -1,9 +1,13 @@
 import React from 'react'
 
+import type { FC } from 'react'
+
 type Props = { children: React.ReactNode }
 
 
-export default ({ children }: Props) => (
+const PageTitle: FC<Props> = ({ children }) => (
     <h1 className="text-2xl font-bold mb-2">
       {children}
     </h1>)
+
+export default PageTitle

frontend/src/components/common/Pagination.test.tsx

@@ -0,0 +1,38 @@
+import { screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import Pagination from '@/components/common/Pagination'
+import { renderWithProviders } from '@/test/render'
+
+describe ('Pagination', () => {
+  it ('builds page links while preserving existing query parameters', () => {
+    renderWithProviders (
+        <Pagination page={3} totalPages={5} siblingCount={1}/>,
+        { route: '/posts?tags=abc&page=3' },
+    )
+
+    expect (screen.getByLabelText ('前のページ')).toHaveAttribute (
+        'href',
+        '/posts?tags=abc&page=2',
+    )
+    expect (screen.getByLabelText ('次のページ')).toHaveAttribute (
+        'href',
+        '/posts?tags=abc&page=4',
+    )
+    expect (screen.getByText ('3')).toHaveAttribute ('aria-current', 'page')
+  })
+
+  it ('does not render active previous and next controls at the edges', () => {
+    const { rerender } = renderWithProviders (
+        <Pagination page={1} totalPages={1}/>,
+        { route: '/tags' },
+    )
+
+    expect (screen.queryByLabelText ('前のページ')).not.toBeInTheDocument ()
+    expect (screen.queryByLabelText ('次のページ')).not.toBeInTheDocument ()
+
+    rerender (<Pagination page={1} totalPages={2}/>)
+
+    expect (screen.getByLabelText ('次のページ')).toHaveAttribute ('href', '/tags?page=2')
+  })
+})

frontend/src/components/common/Pagination.tsx

@@ -48,7 +48,7 @@ const getPages = (
 }
 
 
-export default (({ page, totalPages, siblingCount = 3 }) => {
+const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
   const location = useLocation ()
 
   const buildTo = (p: number) => {
@@ -124,4 +124,6 @@ export default (({ page, totalPages, siblingCount = 3 }) => {
 	      </>)}
 	</div>
       </nav>)
-}) satisfies FC<Props>
+}
+
+export default Pagination

frontend/src/components/common/SectionTitle.tsx

@@ -5,7 +5,9 @@ import type { ComponentPropsWithoutRef, FC } from 'react'
 type Props = ComponentPropsWithoutRef<'h2'>
 
 
-export default (({ children, className, ...rest }: Props) => (
+const SectionTitle: FC<Props> = ({ children, className, ...rest }) => (
     <h2 {...rest} className={cn ('text-xl my-4', className)}>
       {children}
-    </h2>)) satisfies FC<Props>
+    </h2>)
+
+export default SectionTitle

frontend/src/components/common/SubsectionTitle.tsx

@@ -1,9 +1,13 @@
 import React from 'react'
 
+import type { FC } from 'react'
+
 type Props = { children: React.ReactNode }
 
 
-export default ({ children }: Props) => (
+const SubsectionTitle: FC<Props> = ({ children }) => (
     <h3 className="my-2">
       {children}
     </h3>)
+
+export default SubsectionTitle

frontend/src/components/common/TabGroup.test.tsx

@@ -0,0 +1,23 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import TabGroup, { Tab } from '@/components/common/TabGroup'
+
+describe ('TabGroup', () => {
+  it ('uses the init tab and switches tabs when clicked', () => {
+    render (
+        <TabGroup>
+          <Tab name="A">Alpha</Tab>
+          <Tab name="B" init>Beta</Tab>
+        </TabGroup>,
+    )
+
+    expect (screen.queryByText ('Alpha')).not.toBeInTheDocument ()
+    expect (screen.getByText ('Beta')).toBeInTheDocument ()
+
+    fireEvent.click (screen.getByText ('A'))
+
+    expect (screen.getByText ('Alpha')).toBeInTheDocument ()
+    expect (screen.queryByText ('Beta')).not.toBeInTheDocument ()
+  })
+})

frontend/src/components/common/TabGroup.tsx

@@ -1,3 +1,5 @@
+import type { FC } from 'react'
+
 import React, { useState } from 'react'
 import { cn } from '@/lib/utils'
 
@@ -10,7 +12,7 @@ type Props = { children: React.ReactNode }
 export const Tab = ({ children }: TabProps) => <>{children}</>
 
 
-export default ({ children }: Props) => {
+const TabGroup: FC<Props> = ({ children }) => {
   const tabs = React.Children.toArray (children) as React.ReactElement<TabProps>[]
 
   const [current, setCurrent] = useState<number> (() => {
@@ -37,3 +39,5 @@ export default ({ children }: Props) => {
 	</div>
       </div>)
 }
+
+export default TabGroup

frontend/src/components/common/TagInput.test.tsx

@@ -0,0 +1,44 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import TagInput from '@/components/common/TagInput'
+import { buildTag } from '@/test/factories'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('TagInput', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('updates value and fetches autocomplete for the last token', async () => {
+    const setValue = vi.fn ()
+    api.apiGet.mockResolvedValueOnce ([buildTag ({ name: '虹夏', postCount: 2 })])
+
+    render (<TagInput value="ぼっち 虹" setValue={setValue}/>)
+
+    fireEvent.change (screen.getByRole ('textbox'), { target: { value: 'ぼっち 虹夏' } })
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenCalledWith (
+          '/tags/autocomplete',
+          { params: { q: '虹夏' } },
+      )
+    })
+    expect (setValue).toHaveBeenCalledWith ('ぼっち 虹夏')
+  })
+
+  it ('does not fetch when the last token is blank', () => {
+    const setValue = vi.fn ()
+    render (<TagInput value="" setValue={setValue}/>)
+
+    fireEvent.change (screen.getByRole ('textbox'), { target: { value: ' ' } })
+
+    expect (api.apiGet).not.toHaveBeenCalled ()
+    expect (setValue).toHaveBeenCalledWith (' ')
+  })
+})

frontend/src/components/common/TagInput.tsx

@@ -12,7 +12,7 @@ type Props = {
     value:      string
     setValue:   (value: string) => void }
 
-export default (({ value, setValue }: Props) => {
+const TagInput: FC<Props> = ({ value, setValue }) => {
   const [activeIndex, setActiveIndex] = useState (-1)
   const [suggestions, setSuggestions] = useState<Tag[]> ([])
   const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
@@ -62,9 +62,12 @@ export default (({ value, setValue }: Props) => {
     case 'Enter':
       if (activeIndex < 0)
 	break
+      {
 	ev.preventDefault ()
 	const selected = suggestions[activeIndex]
-      selected && handleTagSelect (selected)
+	if (selected)
+	  handleTagSelect (selected)
+      }
       break
 
     case 'Escape':
@@ -94,4 +97,6 @@ export default (({ value, setValue }: Props) => {
 	    activeIndex={activeIndex}
 	    onSelect={handleTagSelect}/>
       </div>)
-}) satisfies FC<Props>
+}
+
+export default TagInput

frontend/src/components/common/TypographyAndForm.test.tsx

@@ -0,0 +1,37 @@
+import { createRef } from 'react'
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import Form from '@/components/common/Form'
+import SectionTitle from '@/components/common/SectionTitle'
+import SubsectionTitle from '@/components/common/SubsectionTitle'
+import TextArea from '@/components/common/TextArea'
+
+describe ('common typography and form components', () => {
+  it ('renders Form children inside the standard container', () => {
+    render (<Form><span>Content</span></Form>)
+
+    expect (screen.getByText ('Content')).toBeInTheDocument ()
+  })
+
+  it ('renders SectionTitle as an h2', () => {
+    render (<SectionTitle>Section</SectionTitle>)
+
+    expect (screen.getByRole ('heading', { level: 2, name: 'Section' })).toBeInTheDocument ()
+  })
+
+  it ('renders SubsectionTitle as an h3', () => {
+    render (<SubsectionTitle>Subsection</SubsectionTitle>)
+
+    expect (screen.getByRole ('heading', { level: 3, name: 'Subsection' })).toBeInTheDocument ()
+  })
+
+  it ('forwards refs and props to TextArea', () => {
+    const ref = createRef<HTMLTextAreaElement> ()
+
+    render (<TextArea ref={ref} aria-label="Body" defaultValue="text"/>)
+
+    expect (ref.current).toBe (screen.getByLabelText ('Body'))
+    expect (screen.getByLabelText ('Body')).toHaveValue ('text')
+  })
+})

frontend/src/components/dialogues/DialogueProvider.tsx

@@ -5,6 +5,7 @@ import { Dialog,
 	 DialogContent,
 	 DialogDescription,
 	 DialogFooter,
+	 DialogHeader,
 	 DialogTitle } from '@/components/ui/dialog'
 
 import type { FC, ReactNode } from 'react'
@@ -56,7 +57,7 @@ let nextDialogueId = 1
 type Props = { children: ReactNode }
 
 
-export default (({ children }: Props) => {
+const DialogueProvider: FC<Props> = ({ children }) => {
   const [queue, setQueue] = useState<DialogueRequest[]> ([])
 
   const push = useCallback ((request: Omit<DialogueRequest, 'id'>) => {
@@ -118,13 +119,15 @@ export default (({ children }: Props) => {
 		closeActive (active?.kind !== 'confirm' && null)
 	    }}>
 	  {active && (
-	      <DialogContent>
+	      <DialogContent className="px-6 pb-6 pt-7">
+		<DialogHeader className="pl-8">
 		  <DialogTitle>{active.options.title}</DialogTitle>
 
 		  {active.options.description && (
 		      <DialogDescription asChild>
 			<div>{active.options.description}</div>
 		      </DialogDescription>)}
+		</DialogHeader>
 
 		<DialogFooter>
 		  {active.kind === 'confirm' && (
@@ -171,7 +174,7 @@ export default (({ children }: Props) => {
 	      </DialogContent>)}
 	</Dialog>
       </DialogueContext.Provider>)
-}) satisfies FC<Props>
+}
 
 
 export const useDialogue = () => {
@@ -182,3 +185,5 @@ export const useDialogue = () => {
 
   return dialogue
 }
+
+export default DialogueProvider

frontend/src/components/layout/MainArea.tsx

@@ -9,10 +9,12 @@ type Props = {
     className?: string }
 
 
-export default (({ children, className }: Props) => (
+const MainArea: FC<Props> = ({ children, className }) => (
     <motion.main
 	transition={{ layout: { duration: .2, ease: 'easeOut' } }}
 	className={cn ('flex-1 overflow-y-auto p-4', className)}
 	layout="position">
       {children}
-    </motion.main>)) satisfies FC<Props>
+    </motion.main>)
+
+export default MainArea

frontend/src/components/layout/SidebarComponent.tsx

@@ -6,7 +6,7 @@ import type { FC, ReactNode } from 'react'
 type Props = { children: ReactNode }
 
 
-export default (({ children }: Props) => (
+const SidebarComponent: FC<Props> = ({ children }) => (
     <motion.div
 	layout="position"
 	transition={{ layout: { duration: .2, ease: 'easeOut' } }}
@@ -27,4 +27,6 @@ export default (({ children }: Props) => (
       </Helmet>
 
       {children}
-    </motion.div>)) satisfies FC<Props>
+    </motion.div>)
+
+export default SidebarComponent

frontend/src/components/ui/button.tsx

@@ -4,34 +4,47 @@ import { cva, type VariantProps } from "class-variance-authority"
 
 import { cn } from "@/lib/utils"
 
-const buttonVariants = cva(
+const buttonVariants = cva (
-  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0",
+  [
+    'inline-flex items-center justify-center gap-2 whitespace-nowrap',
+    'rounded-md text-sm font-medium transition-colors',
+    'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-slate-400',
+    'disabled:pointer-events-none disabled:opacity-50',
+    '[&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0',
+  ].join (' '),
   {
     variants: {
       variant: {
-        default: "bg-primary text-primary-foreground hover:bg-primary/90",
+        default:
+          'bg-slate-900 text-white hover:bg-slate-700 dark:bg-slate-100 dark:text-slate-900 dark:hover:bg-slate-300',
+
         destructive:
-          "bg-destructive text-destructive-foreground hover:bg-destructive/90",
+          'bg-red-600 text-white hover:bg-red-700 dark:bg-red-700 dark:hover:bg-red-600',
+
         outline:
-          "border border-input bg-background hover:bg-accent hover:text-accent-foreground",
+          'border border-slate-300 bg-white text-slate-900 hover:bg-slate-100 dark:border-slate-700 dark:bg-slate-900 dark:text-slate-100 dark:hover:bg-slate-800',
+
         secondary:
-          "bg-secondary text-secondary-foreground hover:bg-secondary/80",
+          'bg-slate-100 text-slate-900 hover:bg-slate-200 dark:bg-slate-800 dark:text-slate-100 dark:hover:bg-slate-700',
-        ghost: "hover:bg-accent hover:text-accent-foreground",
+
-        link: "text-primary underline-offset-4 hover:underline",
+        ghost:
+          'text-slate-900 hover:bg-slate-100 dark:text-slate-100 dark:hover:bg-slate-800',
+
+        link:
+          'text-blue-700 underline-offset-4 hover:underline dark:text-blue-300',
       },
       size: {
-        default: "h-10 px-4 py-2",
+        default: 'h-10 px-4 py-2',
-        sm: "h-9 rounded-md px-3",
+        sm:      'h-9 rounded-md px-3',
-        lg: "h-11 rounded-md px-8",
+        lg:      'h-11 rounded-md px-8',
-        icon: "h-10 w-10",
+        icon:    'h-10 w-10',
       },
     },
     defaultVariants: {
-      variant: "default",
+      variant: 'default',
-      size: "default",
+      size:    'default',
     },
-  }
+  })
-)
 
 export interface ButtonProps
   extends React.ButtonHTMLAttributes<HTMLButtonElement>,

frontend/src/components/ui/dialog.tsx

@@ -50,14 +50,16 @@ const DialogContent = React.forwardRef<
       {...props}
     >
       {children}
+
       <DialogPrimitive.Close
 	  className={cn (
-	      'absolute right-4 top-4 rounded-full p-1',
+	      'absolute left-4 top-4 rounded-full p-1',
-	      'text-muted-foreground opacity-70 transition-opacity',
+	      'text-slate-500 transition-colors',
-	      'hover:bg-accent hover:text-accent-foreground hover:opacity-100',
+	      'hover:bg-slate-200 hover:text-slate-900',
-	      'focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2')}>
+	      'dark:text-slate-400 dark:hover:bg-slate-700 dark:hover:text-slate-50',
+	      'focus:outline-none focus:ring-2 focus:ring-slate-400')}>
 	<X className="h-4 w-4"/>
-	<span className="sr-only">Close</span>
+	<span className="sr-only">閉ぢる</span>
       </DialogPrimitive.Close>
     </DialogPrimitive.Content>
   </DialogPortal>

frontend/src/components/ui/use-toast.tsx

@@ -18,13 +18,6 @@ type ToasterToast = ToastProps & {
   action?: ToastActionElement
 }
 
-const actionTypes = {
-  ADD_TOAST: "ADD_TOAST",
-  UPDATE_TOAST: "UPDATE_TOAST",
-  DISMISS_TOAST: "DISMISS_TOAST",
-  REMOVE_TOAST: "REMOVE_TOAST",
-} as const
-
 let count = 0
 
 function genId() {
@@ -32,23 +25,21 @@ function genId() {
   return count.toString()
 }
 
-type ActionType = typeof actionTypes
-
 type Action =
   | {
-      type: ActionType["ADD_TOAST"]
+      type: "ADD_TOAST"
       toast: ToasterToast
     }
   | {
-      type: ActionType["UPDATE_TOAST"]
+      type: "UPDATE_TOAST"
       toast: Partial<ToasterToast>
     }
   | {
-      type: ActionType["DISMISS_TOAST"]
+      type: "DISMISS_TOAST"
       toastId?: ToasterToast["id"]
     }
   | {
-      type: ActionType["REMOVE_TOAST"]
+      type: "REMOVE_TOAST"
       toastId?: ToasterToast["id"]
     }
 

frontend/src/components/users/InheritDialogue.tsx

@@ -1,8 +1,13 @@
+import type { FC } from 'react'
+
 import { useState } from 'react'
 
+import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { Dialog,
 	 DialogContent,
+	 DialogDescription,
+	 DialogHeader,
 	 DialogTitle } from '@/components/ui/dialog'
 import { Input } from '@/components/ui/input'
 import { toast } from '@/components/ui/use-toast'
@@ -15,11 +20,17 @@ type Props = { visible:         boolean
 	       setUser:         (user: User) => void }
 
 
-export default ({ visible, onVisibleChange, setUser }: Props) => {
+const InheritDialogue: FC<Props> = ({ visible, onVisibleChange, setUser }) => {
+  const dialogue = useDialogue ()
+
   const [inputCode, setInputCode] = useState ('')
 
   const handleTransfer = async () => {
-    if (!(confirm ('引継ぎを行ってもよろしいですか?\n現在のアカウントからはログアウトされます．')))
+    if (!(await dialogue.confirm ({
+	title: '引継ぎを行ってもよろしいですか?',
+	description: '現在のアカウントからはログアウトされます．',
+	confirmText: '引継ぐ',
+	variant: 'danger' })))
       return
 
     try
@@ -44,14 +55,20 @@ export default ({ visible, onVisibleChange, setUser }: Props) => {
 
   return (
       <Dialog open={visible} onOpenChange={onVisibleChange}>
-	<DialogContent>
+	<DialogContent className="px-6 pp-6 pt-7">
+	  <DialogHeader className="pl-8">
 	    <DialogTitle>ほかのブラウザから引継ぐ</DialogTitle>
+	    <DialogDescription asChild>
 	      <div className="flex gap-2">
 		<Input placeholder="引継ぎコードを入力"
 		       value={inputCode}
 		       onChange={ev => setInputCode (ev.target.value)}/>
 		<Button onClick={handleTransfer}>引継ぐ</Button>
 	      </div>
+	    </DialogDescription>
+	  </DialogHeader>
 	</DialogContent>
       </Dialog>)
 }
+
+export default InheritDialogue

frontend/src/components/users/UserCodeDialogue.tsx

@@ -1,6 +1,12 @@
+import type { FC } from 'react'
+
+import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { Dialog,
 	 DialogContent,
+	 DialogDescription,
+	 DialogFooter,
+	 DialogHeader,
 	 DialogTitle } from '@/components/ui/dialog'
 import { toast } from '@/components/ui/use-toast'
 import { apiPost } from '@/lib/api'
@@ -13,12 +19,21 @@ type Props = { visible:         boolean
 	       setUser:         React.Dispatch<React.SetStateAction<User | null>> }
 
 
-export default ({ visible, onVisibleChange, user, setUser }: Props) => {
+const UserCodeDialogue: FC<Props> = ({ visible, onVisibleChange, user, setUser }) => {
+  const dialogue = useDialogue ()
+
   const handleChange = async () => {
     if (!(user))
       return
 
-    if (!(confirm ('引継ぎコードを再発行しますか?\n再発行するとほかのブラウザからはログアウトされます．')))
+    if (!(await dialogue.confirm ({
+	title: '引継ぎコードを再発行しますか?',
+	description: (
+	    <div>
+	      <p>再発行するとほかのブラウザからはログアウトされます．</p>
+	    </div>),
+	confirmText: '再発行',
+	variant: 'danger' })))
       return
 
     const data = await apiPost<{ code: string }> ('/users/code/renew', { },
@@ -33,21 +48,28 @@ export default ({ visible, onVisibleChange, user, setUser }: Props) => {
 
   return (
       <Dialog open={visible} onOpenChange={onVisibleChange}>
-	<DialogContent>
+	<DialogContent className="px-6 pb-6 pt-7">
+	  <DialogHeader className="pl-8">
 	    <DialogTitle>引継ぎコード</DialogTitle>
+
+	    <DialogDescription asChild>
 	      <div>
 		<p>あなたの引継ぎコードはこちらです：</p>
 		<div className="m-2">{user?.inheritanceCode}</div>
-	    <p className="mt-1 text-sm text-red-500">
+		<p className="mt-1 text-sm text-destructive">
 		  このコードはほかの人には教えないでください!
 		</p>
-	    <div className="my-4">
+	      </div>
-	      <Button onClick={handleChange}
+	    </DialogDescription>
-		      className="px-4 py-2 bg-red-600 text-white rounded disabled:bg-gray-400">
+	  </DialogHeader>
+
+	  <DialogFooter>
+	    <Button onClick={handleChange} variant="destructive">
 	      引継ぎコード再発行
 	    </Button>
-	    </div>
+	  </DialogFooter>
-	  </div>
 	</DialogContent>
       </Dialog>)
 }
+
+export default UserCodeDialogue

frontend/src/lib/api.test.ts

@@ -0,0 +1,96 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocks = vi.hoisted (() => {
+  const client = {
+    delete: vi.fn (),
+    get:    vi.fn (),
+    patch:  vi.fn (),
+    post:   vi.fn (),
+    put:    vi.fn (),
+  }
+
+  return {
+    client,
+    isAxiosError: vi.fn (),
+  }
+})
+
+vi.mock ('axios', () => ({
+  default: {
+    create:       vi.fn (() => mocks.client),
+    isAxiosError: mocks.isAxiosError,
+  },
+}))
+
+vi.mock ('@/config', () => ({
+  API_BASE_URL: '/api',
+}))
+
+describe ('api helpers', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    localStorage.clear ()
+  })
+
+  it ('adds the transfer code header and camelizes get responses', async () => {
+    localStorage.setItem ('user_code', 'abc123')
+    mocks.client.get.mockResolvedValueOnce ({
+      data: { post_id: 1, nested_value: { created_at: 'now' } },
+    })
+
+    const { apiGet } = await import ('@/lib/api')
+    const data = await apiGet<{ postId: number; nestedValue: { createdAt: string } }> (
+        '/posts/1',
+        { headers: { 'X-Extra': '1' }, params: { page: 2 } },
+    )
+
+    expect (mocks.client.get).toHaveBeenCalledWith (
+        '/posts/1',
+        {
+          headers: { 'X-Transfer-Code': 'abc123', 'X-Extra': '1' },
+          params:  { page: 2 },
+        },
+    )
+    expect (data).toEqual ({ postId: 1, nestedValue: { createdAt: 'now' } })
+  })
+
+  it ('passes an empty body for post-like requests when body is omitted', async () => {
+    mocks.client.patch.mockResolvedValueOnce ({ data: { ok_value: true } })
+
+    const { apiPatch } = await import ('@/lib/api')
+    const data = await apiPatch<{ okValue: boolean }> ('/posts/1')
+
+    expect (mocks.client.patch).toHaveBeenCalledWith (
+        '/posts/1',
+        {},
+        { headers: { 'X-Transfer-Code': '' } },
+    )
+    expect (data.okValue).toBe (true)
+  })
+
+  it ('does not camelize blob responses', async () => {
+    const blob = new Blob (['csv'])
+    mocks.client.get.mockResolvedValueOnce ({ data: blob })
+
+    const { apiGet } = await import ('@/lib/api')
+    const data = await apiGet<Blob> ('/exports', { responseType: 'blob' })
+
+    expect (data).toBe (blob)
+  })
+
+  it ('delegates deletes and exposes axios error detection', async () => {
+    const err = new Error ('bad')
+    mocks.client.delete.mockResolvedValueOnce ({})
+    mocks.isAxiosError.mockReturnValueOnce (true)
+
+    const { apiDelete, isApiError } = await import ('@/lib/api')
+    await apiDelete ('/posts/1')
+
+    expect (mocks.client.delete).toHaveBeenCalledWith (
+        '/posts/1',
+        { headers: { 'X-Transfer-Code': '' } },
+    )
+    expect (isApiError (err)).toBe (true)
+    expect (mocks.isAxiosError).toHaveBeenCalledWith (err)
+  })
+})

frontend/src/lib/api.ts

@@ -28,7 +28,7 @@ const apiP = async <T> (
   const res = await client[method] (path, body ?? { }, withUserCode (opt))
   if (opt?.responseType === 'blob')
     return res.data as T
-  return toCamel (res.data as any, { deep: true }) as T
+  return toCamel (res.data as Record<string, unknown>, { deep: true }) as T
 }
 
 
@@ -39,7 +39,7 @@ export const apiGet = async <T> (
   const res = await client.get (path, withUserCode (opt))
   if (opt?.responseType === 'blob')
     return res.data as T
-  return toCamel (res.data as any, { deep: true }) as T
+  return toCamel (res.data as Record<string, unknown>, { deep: true }) as T
 }
 
 
@@ -72,4 +72,5 @@ export const apiDelete = async (
 }
 
 
-export const isApiError = (err: unknown): err is AxiosError => axios.isAxiosError (err)
+export const isApiError = <T = unknown> (err: unknown): err is AxiosError<T> =>
+    axios.isAxiosError (err)

frontend/src/lib/posts.test.ts

@@ -0,0 +1,117 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchPostChanges, fetchPosts, toggleViewedFlg, updatePost } from '@/lib/posts'
+
+import type { FetchPostsParams } from '@/types'
+
+const api = vi.hoisted (() => ({
+  apiDelete: vi.fn (),
+  apiGet:    vi.fn (),
+  apiPost:   vi.fn (),
+  apiPut:    vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+const baseParams: FetchPostsParams = {
+  url:                 '',
+  title:               '',
+  tags:                '',
+  match:               'all',
+  originalCreatedFrom: '',
+  originalCreatedTo:   '',
+  createdFrom:         '',
+  createdTo:           '',
+  updatedFrom:         '',
+  updatedTo:           '',
+  page:                1,
+  limit:               20,
+  order:               'updated_at:desc',
+}
+
+describe ('posts API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('maps post search parameters to backend snake_case names', async () => {
+    api.apiGet.mockResolvedValueOnce ({ posts: [], count: 0 })
+
+    await fetchPosts ({
+      ...baseParams,
+      title:               'title',
+      tags:                'a b',
+      originalCreatedFrom: '2026-01-01',
+      updatedTo:           '2026-02-01',
+    })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/posts',
+        {
+          params: {
+            title:                 'title',
+            tags:                  'a b',
+            match:                 'all',
+            original_created_from: '2026-01-01',
+            updated_to:            '2026-02-01',
+            page:                  1,
+            limit:                 20,
+            order:                 'updated_at:desc',
+          },
+        },
+    )
+  })
+
+  it ('updates posts with version and merge controls', async () => {
+    api.apiPut.mockResolvedValueOnce ({ id: 5 })
+
+    await updatePost (
+        {
+          id:                    5,
+          title:                 'new title',
+          tags:                  'tag',
+          parentPostIds:         '1 2',
+          originalCreatedFrom:   null,
+          originalCreatedBefore: '2026-01-02T00:00:00Z',
+        },
+        { baseVersionNo: 7, force: true, merge: false },
+    )
+
+    expect (api.apiPut).toHaveBeenCalledWith (
+        '/posts/5',
+        {
+          title:                   'new title',
+          tags:                    'tag',
+          parent_post_ids:         '1 2',
+          original_created_from:   null,
+          original_created_before: '2026-01-02T00:00:00Z',
+        },
+        {
+          params: {
+            base_version_no: '7',
+            force:           '1',
+            merge:           '0',
+          },
+        },
+    )
+  })
+
+  it ('uses the viewed endpoint method matching the requested state', async () => {
+    await toggleViewedFlg ('9', true)
+    await toggleViewedFlg ('9', false)
+
+    expect (api.apiPost).toHaveBeenCalledWith ('/posts/9/viewed')
+    expect (api.apiDelete).toHaveBeenCalledWith ('/posts/9/viewed')
+  })
+
+  it ('keeps optional post history filters out when blank', async () => {
+    api.apiGet.mockResolvedValueOnce ({ versions: [], count: 0 })
+
+    await fetchPostChanges ({ page: 2, limit: 50 })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/posts/versions',
+        { params: { page: 2, limit: 50 } },
+    )
+  })
+})

frontend/src/lib/prefetchers.test.ts

@@ -0,0 +1,112 @@
+import { QueryClient } from '@tanstack/react-query'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { prefetchForURL } from '@/lib/prefetchers'
+
+const postsApi = vi.hoisted (() => ({
+  fetchPost:        vi.fn (),
+  fetchPostChanges: vi.fn (),
+  fetchPosts:       vi.fn (),
+}))
+
+const tagsApi = vi.hoisted (() => ({
+  fetchTag:        vi.fn (),
+  fetchTagByName:  vi.fn (),
+  fetchTagChanges: vi.fn (),
+  fetchTags:       vi.fn (),
+}))
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPage:        vi.fn (),
+  fetchWikiPageByTitle: vi.fn (),
+  fetchWikiPages:       vi.fn (),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/tags', () => tagsApi)
+vi.mock ('@/lib/wiki', () => wikiApi)
+
+const qc = () => new QueryClient ({
+  defaultOptions: { queries: { retry: false } },
+})
+
+describe ('prefetchForURL', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    postsApi.fetchPosts.mockResolvedValue ({ posts: [], count: 0 })
+    postsApi.fetchPost.mockResolvedValue ({ id: 1 })
+    postsApi.fetchPostChanges.mockResolvedValue ({ versions: [], count: 0 })
+    tagsApi.fetchTags.mockResolvedValue ({ tags: [], count: 0 })
+    tagsApi.fetchTag.mockResolvedValue ({ id: 1 })
+    tagsApi.fetchTagByName.mockResolvedValue (null)
+    tagsApi.fetchTagChanges.mockResolvedValue ({ versions: [], count: 0 })
+    wikiApi.fetchWikiPages.mockResolvedValue ([])
+    wikiApi.fetchWikiPage.mockResolvedValue ({ id: 1 })
+    wikiApi.fetchWikiPageByTitle.mockResolvedValue (null)
+  })
+
+  it ('prefetches post indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/posts?tags=a+b&match=any&page=2&limit=5&order=title%3Aasc',
+    )
+
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          tags:  'a b',
+          match: 'any',
+          page:  2,
+          limit: 5,
+          order: 'title:asc',
+        }),
+    )
+  })
+
+  it ('prefetches post detail pages', async () => {
+    await prefetchForURL (qc (), 'http://localhost/posts/12')
+
+    expect (postsApi.fetchPost).toHaveBeenCalledWith ('12')
+  })
+
+  it ('prefetches tag indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/tags?post=9&name=x&category=general&page=4&post_count_lte=10',
+    )
+
+    expect (tagsApi.fetchTags).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          post:         9,
+          name:         'x',
+          category:     'general',
+          page:         4,
+          postCountLTE: 10,
+        }),
+    )
+  })
+
+  it ('prefetches wiki show pages and related tag/post data', async () => {
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce ({
+      id:    3,
+      title: 'Actual',
+      body:  'body',
+    })
+
+    await prefetchForURL (qc (), 'http://localhost/wiki/Alias')
+
+    expect (wikiApi.fetchWikiPageByTitle).toHaveBeenCalledWith ('Alias', { version: undefined })
+    expect (wikiApi.fetchWikiPage).toHaveBeenCalledWith ('3', {})
+    expect (tagsApi.fetchTagByName).toHaveBeenCalledWith ('Actual')
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({ tags: 'Actual', limit: 8 }),
+    )
+  })
+
+  it ('ignores routes without a prefetcher', async () => {
+    await prefetchForURL (qc (), 'http://localhost/unknown')
+
+    expect (postsApi.fetchPosts).not.toHaveBeenCalled ()
+    expect (tagsApi.fetchTags).not.toHaveBeenCalled ()
+    expect (wikiApi.fetchWikiPages).not.toHaveBeenCalled ()
+  })
+})

frontend/src/lib/queryKeys.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, it } from 'vitest'
+
+import { postsKeys, tagsKeys, wikiKeys } from '@/lib/queryKeys'
+
+describe ('query keys', () => {
+  it ('uses stable namespaces for posts, tags, and wiki', () => {
+    expect (postsKeys.show ('3')).toEqual (['posts', '3'])
+    expect (postsKeys.related ('3')).toEqual (['related', '3'])
+    expect (tagsKeys.deerjikists ('7')).toEqual (['tags', 'deerjikists', '7'])
+    expect (wikiKeys.show ('Title', { version: '2' })).toEqual (
+        ['wiki', 'Title', { version: '2' }],
+    )
+  })
+})

frontend/src/lib/remark-wiki-autolink.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, it } from 'vitest'
+
+import remarkWikiAutolink from '@/lib/remark-wiki-autolink'
+
+import type { Root } from 'mdast'
+
+describe ('remarkWikiAutolink', () => {
+  it ('links matching wiki page names and prefers longer matches', () => {
+    const tree: Root = {
+      type:     'root',
+      children: [{
+        type:     'paragraph',
+        children: [{ type: 'text', value: '虹夏 and 虹' }],
+      }],
+    }
+
+    remarkWikiAutolink (['虹', '虹夏']) (tree)
+
+    expect (tree.children[0]).toMatchObject ({
+      type:     'paragraph',
+      children: [
+        {
+          type:     'link',
+          url:      '/wiki/%E8%99%B9%E5%A4%8F',
+          children: [{ type: 'text', value: '虹夏' }],
+        },
+        { type: 'text', value: ' and ' },
+        {
+          type:     'link',
+          url:      '/wiki/%E8%99%B9',
+          children: [{ type: 'text', value: '虹' }],
+        },
+      ],
+    })
+  })
+
+  it ('does not link text inside existing links or code', () => {
+    const tree: Root = {
+      type:     'root',
+      children: [
+        {
+          type:     'paragraph',
+          children: [{
+            type:     'link',
+            url:      '/existing',
+            children: [{ type: 'text', value: '虹' }],
+          }],
+        },
+        {
+          type:  'code',
+          value: '虹',
+        },
+      ],
+    }
+
+    remarkWikiAutolink (['虹']) (tree)
+
+    expect (tree.children[0]).toMatchObject ({
+      type:     'paragraph',
+      children: [{
+        type:     'link',
+        url:      '/existing',
+        children: [{ type: 'text', value: '虹' }],
+      }],
+    })
+    expect (tree.children[1]).toMatchObject ({ type: 'code', value: '虹' })
+  })
+})

frontend/src/lib/remark-wiki-autolink.ts

@@ -38,7 +38,7 @@ export default (pageNames: string[], basePath = '/wiki'): ((tree: Root) => void)
 	      let last = 0
 	      const parts: RootContent[] = []
 
-	      while (m = re.exec (value))
+	      while ((m = re.exec (value)) !== null)
 		{
 		  const start = m.index
 		  const end = start + m[0].length
@@ -70,7 +70,7 @@ export default (pageNames: string[], basePath = '/wiki'): ((tree: Root) => void)
 	    }
 	}
 
-      const maybeChidren = (node as any).children
+      const maybeChidren = 'children' in node ? node.children : undefined
       if (Array.isArray (maybeChidren))
 	{
 	  const parent = node as Parent

frontend/src/lib/tags.test.ts

@@ -0,0 +1,67 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchTag, fetchTagByName, fetchTags } from '@/lib/tags'
+
+import type { FetchTagsParams } from '@/types'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+const baseParams: FetchTagsParams = {
+  post:         null,
+  name:         '',
+  category:     null,
+  postCountGTE: 0,
+  postCountLTE: null,
+  createdFrom:  '',
+  createdTo:    '',
+  updatedFrom:  '',
+  updatedTo:    '',
+  page:         1,
+  limit:        30,
+  order:        'updated_at:desc',
+}
+
+describe ('tags API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('maps tag filters to backend parameters', async () => {
+    api.apiGet.mockResolvedValueOnce ({ tags: [], count: 0 })
+
+    await fetchTags ({
+      ...baseParams,
+      name:         '虹',
+      category:     'character',
+      postCountGTE: 10,
+      postCountLTE: 20,
+    })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/tags',
+        {
+          params: {
+            name:           '虹',
+            category:       'character',
+            post_count_gte: 10,
+            post_count_lte: 20,
+            page:           1,
+            limit:          30,
+            order:          'updated_at:desc',
+          },
+        },
+    )
+  })
+
+  it ('returns null when tag fetches fail', async () => {
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+
+    await expect (fetchTag ('1')).resolves.toBeNull ()
+    await expect (fetchTagByName ('unknown')).resolves.toBeNull ()
+  })
+})

frontend/src/lib/utils.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest'
+
+import { cn, originalCreatedAtString, toDate } from '@/lib/utils'
+
+describe ('utils', () => {
+  it ('converts strings to dates and leaves date instances intact', () => {
+    const date = new Date ('2026-01-02T03:04:05Z')
+
+    expect (toDate ('2026-01-02T03:04:05Z')).toBeInstanceOf (Date)
+    expect (toDate (date)).toBe (date)
+  })
+
+  it ('merges conditional Tailwind classes', () => {
+    const hidden = false
+
+    expect (cn ('p-2', hidden && 'hidden', 'p-4')).toBe ('p-4')
+  })
+
+  it ('renders unknown original creation time ranges', () => {
+    expect (originalCreatedAtString (null, null)).toBe ('年月日不詳')
+    expect (
+        originalCreatedAtString (
+            '2026-01-01T00:00:00+09:00',
+            '2026-01-02T00:00:00+09:00',
+        ),
+    ).toContain ('時刻不詳')
+  })
+})

frontend/src/lib/utils.ts

@@ -71,3 +71,15 @@ export const originalCreatedAtString = (
 	       .join (' '))
   return rtn === '〜' ? '年月日不詳' : rtn
 }
+
+
+export const msToTime = (ms: number): string => {
+  const totalS = Math.trunc (ms / 1_000)
+  const s = String (totalS % 60)
+  const min = String (Math.trunc (totalS / 60) % 60)
+  const h = Math.trunc (totalS / 3_600)
+
+  return (h > 0
+	  ? `${ h }:${ min.padStart (2, '0') }:${ s.padStart (2, '0') }`
+	  : `${ min }:${ s.padStart (2, '0') }`)
+}

frontend/src/lib/wiki.test.ts

@@ -0,0 +1,48 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchWikiPage, fetchWikiPageByTitle, fetchWikiPages } from '@/lib/wiki'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('wiki API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('fetches wiki index and show pages with expected parameters', async () => {
+    api.apiGet.mockResolvedValueOnce ([])
+    api.apiGet.mockResolvedValueOnce ({ id: 1 })
+
+    await fetchWikiPages ({ title: '虹' })
+    await fetchWikiPage ('1', { version: '3' })
+
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        1,
+        '/wiki',
+        { params: { title: '虹' } },
+    )
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        2,
+        '/wiki/1',
+        { params: { version: '3' } },
+    )
+  })
+
+  it ('encodes title path segments and returns null on misses', async () => {
+    api.apiGet.mockResolvedValueOnce ({ id: 2 })
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+
+    await fetchWikiPageByTitle ('a/b c', { version: undefined })
+    await expect (fetchWikiPageByTitle ('missing', {})).resolves.toBeNull ()
+
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        1,
+        '/wiki/title/a%2Fb%20c',
+        { params: { version: undefined } },
+    )
+  })
+})

frontend/src/pages/Forbidden.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={403}/>
+const Forbidden: FC = () => <ErrorScreen status={403}/>
+
+export default Forbidden

frontend/src/pages/MorePage.tsx

@@ -11,7 +11,7 @@ import type { FC } from 'react'
 import type { User } from '@/types'
 
 
-export default (() => {
+const MorePage: FC = () => {
   const menu = menuOutline (
       { tag: null, wikiId: null, user: { } as User, pathName: location.pathname })
 
@@ -43,4 +43,6 @@ export default (() => {
 		  </section>))}
 	    </div>))}
       </MainArea>)
-}) satisfies FC
+}
+
+export default MorePage

frontend/src/pages/NotFound.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={404}/>
+const NotFound: FC = () => <ErrorScreen status={404}/>
+
+export default NotFound

frontend/src/pages/ServiceUnavailable.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={503}/>
+const ServiceUnavailable: FC = () => <ErrorScreen status={503}/>
+
+export default ServiceUnavailable

frontend/src/pages/deerjikists/DeerjikistDetailPage.tsx

@@ -1,5 +1,6 @@
 import { useQuery, useQueryClient } from '@tanstack/react-query'
-import { useEffect, useState } from 'react'
+import { useEffect, useMemo, useState } from 'react'
+import { Helmet } from 'react-helmet-async'
 import { useParams } from 'react-router-dom'
 
 import TagLink from '@/components/TagLink'
@@ -18,7 +19,7 @@ import type { FC, FormEvent } from 'react'
 import type { Deerjikist, Platform } from '@/types'
 
 
-export default (() => {
+const DeerjikistDetailPage: FC = () => {
   const { id } = useParams ()
   const tagId = String (id ?? '')
   const tagKey = tagsKeys.deerjikists (tagId)
@@ -26,7 +27,7 @@ export default (() => {
   const { data: qData, isLoading: loading } =
       useQuery ({ queryKey: tagKey, queryFn: () => fetchDeerjikistsByTag (tagId) })
   const tag = qData?.tag
-  const deerjikists = qData?.deerjikists ?? []
+  const deerjikists = useMemo (() => qData?.deerjikists ?? [], [qData])
 
   const [data, setData] =
       useState<(Omit<Deerjikist, 'platform'> & { platform: Platform | null })[]> ([])
@@ -69,6 +70,11 @@ export default (() => {
 
   return (
       <MainArea>
+	<Helmet>
+	  <meta name="robots" content="noindex"/>
+	  {tag && <title>{tag.name} | ニジラー情報</title>}
+	</Helmet>
+
 	{(loading || !(tag)) ? 'Loading...' : (
 	    <div className="max-w-xl">
 	      <PageTitle>
@@ -152,4 +158,6 @@ export default (() => {
 	    </div>
 	)}
       </MainArea>)
-}) satisfies FC
+}
+
+export default DeerjikistDetailPage