#302

AGENTS.md

@@ -126,16 +126,12 @@ npm run preview
 - In TypeScript and TSX only, replace every leading run of 8 spaces with a tab.
 - Tabs are only for leading indentation, never for spaces after non-space text.
 - Do not add production dependencies without explicit approval.
-- Do not create, modify, or run tests unless the user explicitly asks for
-  test work. When the user asks for tests, keep working and rerun them until
-  they pass or the remaining failure is clearly blocked.
 
 ## Backend rules
 
 - Inspect existing routes, controllers, models, services, and specs before
   editing backend behavior.
-- For API behavior changes, add or update request specs under
+- For API behavior changes, add or update request specs under `backend/spec/requests`.
-  `backend/spec/requests` only when the user explicitly asks for tests.
 - 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.
@@ -215,11 +211,10 @@ function PostFormTagsArea ({ tags, setTags }: Props) {
   `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 only non-test verification commands that
+- If frontend code changes, run the existing frontend verification commands
-  apply, such as `npm run build` and `npm run lint`. Run `npm run test:run`
+  that apply: `npm run build`, `npm run lint`, and `npm run test:run`.
-  only when the user explicitly asks for tests.
+- If backend code changes, run the relevant RSpec command; for broad backend
-- If backend code changes, do not run RSpec unless the user explicitly asks
+  changes, run `bundle exec rspec`.
-  for tests.
 - If a verification command cannot be run or fails, report the exact command and failure.
 
 ## Completion criteria
@@ -227,8 +222,7 @@ function PostFormTagsArea ({ tags, setTags }: Props) {
 A task is complete only when:
 
 - implementation is complete,
-- relevant non-test verification commands pass, or failures are clearly
+- relevant verification commands pass, or failures are clearly explained,
-  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

@@ -47,10 +47,6 @@ bundle exec rspec
 
 If a command cannot be run or fails, report the exact command and failure.
 
-Do not create, modify, or run tests unless the user explicitly asks for test
-work. When the user asks for tests, keep working and rerun them until they
-pass or the remaining failure is clearly blocked.
-
 ## Rails structure
 
 - `app/controllers`: API controllers.
@@ -120,8 +116,7 @@ service, representation, and spec.
 - `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 only when
+  update request specs covering banned users and banned IP addresses.
-  the user explicitly asks for tests.
 
 ## RSpec
 
@@ -135,9 +130,8 @@ service, representation, and spec.
 - `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 only when the user
+- Add or update request specs for API behavior changes, especially status
-  explicitly asks for tests, especially status codes, permissions, response
+  codes, permissions, response shape, and version conflict behavior.
-  shape, and version conflict behavior.
 
 ## Migrations
 
@@ -170,8 +164,7 @@ service, representation, and spec.
   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. Cover conflicts in request specs only when the user
+  `merge` semantics and cover conflicts in request specs.
-  explicitly asks for tests.
 
 ## Domain cautions
 

backend/app/controllers/gekanator_games_controller.rb

@@ -1,140 +0,0 @@
-class GekanatorGamesController < ApplicationController
-  def create
-    return head :not_found unless current_user&.admin?
-
-    guessed_post_id = params.require(:guessed_post_id)
-    correct_post_id = params[:correct_post_id].presence
-    answers = params.require(:answers).as_json
-
-    game = GekanatorGame.new(
-        user: current_user,
-        guessed_post_id:,
-        correct_post_id:,
-        won: correct_post_id.present? && guessed_post_id.to_i == correct_post_id.to_i,
-        question_count: answers.length,
-        answers:)
-
-    if game.save
-      render json: { id: game.id }, status: :created
-    else
-      render json: { errors: game.errors.full_messages }, status: :unprocessable_entity
-    end
-  end
-
-  def extra_questions
-    return head :not_found unless current_user&.admin?
-
-    game = GekanatorGame.find_by(id: params[:id])
-    return head :not_found unless game
-
-    questions =
-        GekanatorQuestion
-        .accepted
-        .includes(:gekanator_question_examples)
-        .where(kind: 'post_similarity', source: 'user_suggested')
-        .to_a
-
-    selected = weighted_sample_questions(
-        questions,
-        post_id: game.correct_post_id,
-        limit: 2)
-
-    render json: {
-      questions: selected.map { |question| extra_question_json(question) }
-    }
-  end
-
-  def extra_question_answers
-    return head :not_found unless current_user&.admin?
-
-    game = GekanatorGame.find_by(id: params[:id])
-    return head :not_found unless game
-
-    answer_params = params.require(:answers)
-    if !answer_params.is_a?(Array)
-      return render_validation_error fields: { answers: ['配列で指定してください．'] }
-    end
-
-    answers = answer_params.map { |answer|
-      {
-        question_id: answer.require(:question_id).to_i,
-        answer: answer.require(:answer)
-      }
-    }
-    questions = GekanatorQuestion.where(id: answers.map { _1[:question_id] })
-    question_by_id = questions.index_by(&:id)
-    if questions.length != answers.length
-      return render_validation_error fields: { answers: ['質問が見つかりません．'] }
-    end
-    if questions.any? { |question| question.status != 'accepted' || question.kind != 'post_similarity' }
-      return render_validation_error fields: { answers: ['質問が不正です．'] }
-    end
-
-    ActiveRecord::Base.transaction do
-      answers.each do |item|
-        question = question_by_id[item[:question_id]]
-        example =
-            GekanatorQuestionExample.find_or_initialize_by(
-                gekanator_question: question,
-                post: game.correct_post,
-                user: current_user)
-        example.record_answer!(
-            answer: item[:answer],
-            source: 'post_game_extra',
-            gekanator_game: game)
-        example.save!
-      end
-    end
-
-    render json: { count: answers.length }, status: :created
-  end
-
-  private
-
-  def extra_question_json question
-    {
-      id: question.id,
-      text: question.text,
-      source: question.source,
-      priority_weight: question.priority_weight
-    }
-  end
-
-  def weighted_sample_questions questions, post_id:, limit:
-    remaining = questions.uniq(&:id)
-    selected = []
-
-    while selected.length < limit && remaining.any?
-      weighted =
-          remaining.map { |question|
-            [question, selection_weight_for(question, post_id: post_id)]
-          }
-      total_weight = weighted.sum { |_question, weight| weight }
-      break if total_weight <= 0
-
-      target = rand * total_weight
-      cumulative = 0.0
-      chosen =
-          weighted.find do |_question, weight|
-            cumulative += weight
-            cumulative >= target
-          end&.first || weighted.first.first
-
-      selected << chosen
-      remaining.reject! { |question| question.id == chosen.id }
-    end
-
-    selected
-  end
-
-  def selection_weight_for question, post_id:
-    sample_count =
-        question.gekanator_question_examples.sum { |example|
-          next 0 unless example.post_id == post_id
-
-          example.sample_count.presence || 1
-        }
-
-    question.priority_weight.to_f / (1.0 + sample_count * 0.15)
-  end
-end

backend/app/controllers/gekanator_posts_controller.rb

@@ -1,46 +0,0 @@
-class GekanatorPostsController < ApplicationController
-  def index
-    return head :not_found unless current_user&.admin?
-
-    posts =
-        Post
-        .preload(tags: :tag_name)
-        .with_attached_thumbnail
-        .order(Arel.sql(
-            'COALESCE(posts.original_created_before - INTERVAL 1 MINUTE, ' \
-            'posts.original_created_from, posts.created_at) DESC, posts.id DESC'))
-
-    render json: { posts: posts.map { |post| post_json(post) } }
-  end
-
-  private
-
-  def post_json post
-    {
-      id: post.id,
-      url: post.url,
-      title: post.title,
-      thumbnail: thumbnail_url(post),
-      thumbnail_base: post.thumbnail_base,
-      original_created_from: post.original_created_from,
-      original_created_before: post.original_created_before,
-      tags: post.tags.map { |tag| tag_json(tag) }
-    }
-  end
-
-  def tag_json tag
-    {
-      id: tag.id,
-      name: tag.name,
-      category: tag.category
-    }
-  end
-
-  def thumbnail_url post
-    return nil unless post.thumbnail.attached?
-
-    rails_storage_proxy_url(post.thumbnail, only_path: false)
-  rescue
-    nil
-  end
-end

backend/app/controllers/gekanator_question_suggestions_controller.rb

@@ -1,53 +0,0 @@
-class GekanatorQuestionSuggestionsController < ApplicationController
-  def create
-    return head :not_found unless current_user&.admin?
-
-    game = GekanatorGame.find_by(id: params.require(:gekanator_game_id))
-    return head :not_found unless game
-
-    suggestion = GekanatorQuestionSuggestion.new(
-        gekanator_game: game,
-        user: current_user,
-        question_text: params.require(:question_text),
-        answer: params.require(:answer))
-
-    if suggestion.valid?
-      ActiveRecord::Base.transaction do
-        suggestion.save!
-        Gekanator::QuestionSuggestionPromoter.call(
-            suggestion: suggestion,
-            user: current_user)
-      end
-
-      render json: {
-        id: suggestion.id,
-        count: game.question_suggestions.count
-      }, status: :created
-    else
-      render_validation_error suggestion
-    end
-  end
-
-  def ai_convert
-    return head :not_found unless current_user&.admin?
-
-    suggestion = GekanatorQuestionSuggestion.find_by(id: params[:id])
-    return head :not_found unless suggestion
-    if Gekanator::AiRunBudget.exceeded_after_next_run?
-      suggestion.gekanator_ai_runs.create!(
-          model: 'budget_guard',
-          status: 'blocked_budget',
-          input_tokens: 0,
-          output_tokens: 0,
-          estimated_cost_jpy: 0)
-      return head :payment_required
-    end
-
-    Gekanator::QuestionSuggestionAiConverter.call(
-        suggestion: suggestion,
-        user: current_user)
-    head :no_content
-  rescue NotImplementedError
-    head :not_implemented
-  end
-end

backend/app/controllers/gekanator_questions_controller.rb

@@ -1,100 +0,0 @@
-class GekanatorQuestionsController < ApplicationController
-  def index
-    return head :not_found unless current_user&.admin?
-
-    questions =
-        GekanatorQuestion
-        .accepted
-        .includes(:gekanator_question_examples)
-        .order(priority_weight: :desc, id: :asc)
-
-    render json: {
-      questions: questions.map { |question| question_json(question) }
-    }
-  end
-
-  private
-
-  def question_json question
-    condition = condition_json(question.condition).deep_symbolize_keys
-    json = {
-      id: question_id_for(question, condition),
-      text: question_text_for(question, condition),
-      kind: question.kind,
-      condition: condition,
-      source: question.source,
-      priority_weight: question.priority_weight
-    }
-    if question.kind == 'post_similarity'
-      json[:example_answers] = example_answers_json(question)
-    end
-    json
-  end
-
-  def question_id_for question, condition
-    case condition[:type]
-    when 'tag'
-      "tag:#{ condition[:key] }"
-    when 'source'
-      "source:#{ condition[:host] }"
-    when 'original-year'
-      "original-year:#{ condition[:year] }"
-    when 'original-month'
-      "original-month:#{ condition[:month] }"
-    when 'original-month-day'
-      "original-month-day:#{ condition[:monthDay] || condition[:month_day] }"
-    when 'title-length-at-least'
-      "title:length-at-least:#{ condition[:length] }"
-    when 'title-length-greater-than'
-      "title:length-at-least:#{ condition[:length].to_i + 1 }"
-    when 'title-has-ascii'
-      'title:ascii'
-    when 'post-similarity'
-      "post-similarity:#{ question.id }"
-    else
-      "catalog:#{ question.id }"
-    end
-  end
-
-  def condition_json condition
-    json = condition.deep_dup.as_json
-
-    if json['type'] == 'original-month-day' && json['monthDay'].blank?
-      json['monthDay'] = json.delete('month_day')
-    end
-
-    if json['type'] == 'title-length-greater-than'
-      json['type'] = 'title-length-at-least'
-      json['length'] = json['length'].to_i + 1
-    end
-
-    json
-  end
-
-  def question_text_for question, condition
-    return question.text unless question.kind == 'title'
-
-    case condition[:type]
-    when 'title-length-at-least'
-      "タイトルは #{ condition[:length] } 文字以上?"
-    else
-      question.text
-    end
-  end
-
-  def example_answers_json question
-    question
-        .gekanator_question_examples
-        .group_by(&:post_id)
-        .transform_values { |examples| aggregate_answer(examples) }
-  end
-
-  def aggregate_answer examples
-    examples
-        .group_by(&:answer)
-        .map { |answer, grouped| [answer, grouped.sum(&:weight), grouped.max_by(&:updated_at)&.updated_at] }
-        .sort_by { |(_answer, weight, updated_at)| [-weight, -(updated_at&.to_f || 0)] }
-        .first
-        &.first
-  end
-end

backend/app/models/gekanator_ai_run.rb

@@ -1,21 +0,0 @@
-class GekanatorAiRun < ApplicationRecord
-  STATUSES = ['pending', 'running', 'succeeded', 'failed', 'blocked_budget'].freeze
-
-  belongs_to :gekanator_question_suggestion
-
-  validates :model, presence: true, length: { maximum: 255 }
-  validates :status, presence: true, inclusion: { in: STATUSES }
-  validates :input_tokens,
-            presence: true,
-            numericality: { only_integer: true, greater_than_or_equal_to: 0 }
-  validates :output_tokens,
-            presence: true,
-            numericality: { only_integer: true, greater_than_or_equal_to: 0 }
-  validates :estimated_cost_jpy,
-            presence: true,
-            numericality: { greater_than_or_equal_to: 0 }
-
-  scope :this_month, lambda {
-    where(created_at: Time.current.beginning_of_month..Time.current.end_of_month)
-  }
-end

backend/app/models/gekanator_game.rb

@@ -1,15 +0,0 @@
-class GekanatorGame < ApplicationRecord
-  belongs_to :user
-  belongs_to :guessed_post, class_name: 'Post'
-  belongs_to :correct_post, class_name: 'Post'
-  has_many :question_suggestions,
-           class_name: 'GekanatorQuestionSuggestion',
-           dependent: :delete_all
-  has_many :question_examples,
-           class_name: 'GekanatorQuestionExample',
-           dependent: :delete_all
-
-  validates :answers, presence: true
-  validates :question_count, numericality: { greater_than_or_equal_to: 0 }
-  validates :won, inclusion: { in: [true, false] }
-end

backend/app/models/gekanator_question.rb

@@ -1,23 +0,0 @@
-class GekanatorQuestion < ApplicationRecord
-  KINDS = ['tag', 'source', 'title', 'original_date', 'post_similarity'].freeze
-  SOURCES = ['user_suggested', 'ai_generated', 'admin_curated'].freeze
-  STATUSES = ['pending', 'accepted', 'rejected', 'disabled'].freeze
-
-  belongs_to :gekanator_question_suggestion, optional: true
-  belongs_to :created_by, class_name: 'User', optional: true
-  has_many :gekanator_question_examples, dependent: :delete_all
-
-  validates :kind, presence: true, inclusion: { in: KINDS }
-  validates :source, presence: true, inclusion: { in: SOURCES }
-  validates :status, presence: true, inclusion: { in: STATUSES }
-  validates :text, presence: true, length: { maximum: 1000 }
-  validates :condition, presence: true
-  validates :priority_weight,
-            presence: true,
-            numericality: {
-              greater_than: 0,
-              less_than_or_equal_to: 3
-            }
-
-  scope :accepted, -> { where(status: 'accepted') }
-end

backend/app/models/gekanator_question_example.rb

@@ -1,97 +0,0 @@
-class GekanatorQuestionExample < ApplicationRecord
-  ANSWERS = GekanatorQuestionSuggestion::ANSWERS
-  NON_UNKNOWN_ANSWERS = ANSWERS - ['unknown']
-  SOURCES = ['initial_suggestion', 'post_game_extra'].freeze
-
-  belongs_to :gekanator_question
-  belongs_to :post
-  belongs_to :user
-  belongs_to :gekanator_game, optional: true
-
-  validates :answer, presence: true, inclusion: { in: ANSWERS }
-  validates :answer_counts, presence: true
-  validates :sample_count,
-            presence: true,
-            numericality: {
-              only_integer: true,
-              greater_than: 0
-            }
-  validates :source, presence: true, inclusion: { in: SOURCES }
-  validates :weight,
-            presence: true,
-            numericality: {
-              greater_than: 0
-            }
-
-  before_validation :normalize_learning_state
-
-  def record_answer!(answer:, source:, gekanator_game: nil)
-    answer = answer.to_s
-    raise ArgumentError, 'invalid answer' unless ANSWERS.include?(answer)
-
-    counts = normalized_answer_counts
-    counts[answer] += 1
-
-    self.answer_counts = counts
-    self.sample_count = counts.values.sum
-    self.gekanator_game = gekanator_game if gekanator_game.present?
-    self.source = source if new_record?
-
-    apply_aggregated_answer!(preferred_answer: answer)
-    self
-  end
-
-  private
-
-  def normalize_learning_state
-    counts = normalized_answer_counts
-
-    if counts.values.sum.zero? && answer.present?
-      counts[answer] = 1
-    end
-
-    self.answer_counts = counts
-    self.sample_count = counts.values.sum
-
-    apply_aggregated_answer!
-  end
-
-  def apply_aggregated_answer!(preferred_answer: nil)
-    counts = normalized_answer_counts
-    known_counts = counts.slice(*NON_UNKNOWN_ANSWERS)
-    known_total = known_counts.values.sum
-
-    if known_total.zero?
-      self.answer = 'unknown'
-      self.weight = 0.1
-      return
-    else
-      max_count = known_counts.values.max
-      candidates = known_counts.select { |_answer, count| count == max_count }.keys
-      self.answer =
-          if preferred_answer.present? && candidates.include?(preferred_answer)
-            preferred_answer
-          elsif answer.present? && candidates.include?(answer)
-            answer
-          else
-            candidates.first
-          end
-    end
-
-    consensus = max_count.to_f / known_total
-    self.weight = Math.sqrt(known_total) * consensus
-  end
-
-  def normalized_answer_counts
-    base = ANSWERS.index_with(0)
-
-    answer_counts.to_h.each do |key, value|
-      answer_key = key.to_s
-      next unless ANSWERS.include?(answer_key)
-
-      base[answer_key] = value.to_i
-    end
-
-    base
-  end
-end

backend/app/models/gekanator_question_suggestion.rb

@@ -1,25 +0,0 @@
-class GekanatorQuestionSuggestion < ApplicationRecord
-  MAX_QUESTIONS_PER_GAME = 3
-  ANSWERS = ['yes', 'no', 'partial', 'probably_no', 'unknown'].freeze
-
-  belongs_to :gekanator_game
-  belongs_to :user
-  has_many :gekanator_questions, dependent: :nullify
-  has_many :gekanator_ai_runs, dependent: :destroy
-
-  validates :question_text, presence: true, length: { maximum: 1000 }
-  validates :answer, presence: true, inclusion: { in: ANSWERS }
-  validates :processed, inclusion: { in: [true, false] }
-  validate :question_suggestion_limit_per_game, on: :create
-
-  private
-
-  def question_suggestion_limit_per_game
-    return if gekanator_game_id.blank?
-
-    count = GekanatorQuestionSuggestion.where(gekanator_game_id:).count
-    if count >= MAX_QUESTIONS_PER_GAME
-      errors.add(:base, '質問追加数を超えてゐます．')
-    end
-  end
-end

backend/app/models/post.rb

@@ -11,17 +11,6 @@ class Post < ApplicationRecord
   has_many :user_post_views, dependent: :delete_all
   has_many :post_similarities, dependent: :delete_all
   has_many :post_versions
-  has_many :gekanator_guessed_games,
-           class_name: 'GekanatorGame',
-           foreign_key: :guessed_post_id,
-           dependent: :delete_all,
-           inverse_of: :guessed_post
-  has_many :gekanator_correct_games,
-           class_name: 'GekanatorGame',
-           foreign_key: :correct_post_id,
-           dependent: :delete_all,
-           inverse_of: :correct_post
-  has_many :gekanator_question_examples, dependent: :delete_all
 
   has_many :parent_post_implications,
            class_name: 'PostImplication',

backend/app/services/gekanator/ai_run_budget.rb

@@ -1,22 +0,0 @@
-module Gekanator
-  class AiRunBudget
-    MONTHLY_LIMIT_JPY = BigDecimal('450').freeze
-    MAX_RUN_ESTIMATED_COST_JPY = BigDecimal('5').freeze
-
-    def self.remaining_monthly_budget_jpy
-      MONTHLY_LIMIT_JPY - monthly_cost_jpy
-    end
-
-    def self.monthly_cost_jpy
-      GekanatorAiRun.this_month.sum(:estimated_cost_jpy)
-    end
-
-    def self.exceeded?
-      monthly_cost_jpy >= MONTHLY_LIMIT_JPY
-    end
-
-    def self.exceeded_after_next_run?
-      monthly_cost_jpy + MAX_RUN_ESTIMATED_COST_JPY >= MONTHLY_LIMIT_JPY
-    end
-  end
-end

backend/app/services/gekanator/question_suggestion_ai_converter.rb

@@ -1,18 +0,0 @@
-module Gekanator
-  class QuestionSuggestionAiConverter
-    def self.call(...) = new(...).call
-
-    def initialize suggestion:, user:
-      @suggestion = suggestion
-      @user = user
-    end
-
-    def call
-      raise NotImplementedError, 'AI question conversion is not implemented yet.'
-    end
-
-    private
-
-    attr_reader :suggestion, :user
-  end
-end

backend/app/services/gekanator/question_suggestion_promoter.rb

@@ -1,52 +0,0 @@
-module Gekanator
-  class QuestionSuggestionPromoter
-    def self.call(...) = new(...).call
-
-    def initialize suggestion:, user:
-      @suggestion = suggestion
-      @user = user
-    end
-
-    def call
-      suggestion.with_lock do
-        return promoted_question if suggestion.processed?
-        return suggestion if suggestion.answer == 'unknown'
-
-        question = GekanatorQuestion.create!(
-            text: suggestion.question_text,
-            kind: 'post_similarity',
-            source: 'user_suggested',
-            status: 'accepted',
-            priority_weight: 1.2,
-            condition: {
-              type: 'post-similarity',
-              postId: suggestion.gekanator_game.correct_post_id,
-              answer: suggestion.answer,
-              threshold: 0.65
-            },
-            gekanator_question_suggestion: suggestion,
-            created_by: user)
-        example =
-            GekanatorQuestionExample.new(
-                gekanator_question: question,
-                post: suggestion.gekanator_game.correct_post,
-                user: user)
-        example.record_answer!(
-            answer: suggestion.answer,
-            source: 'initial_suggestion',
-            gekanator_game: suggestion.gekanator_game)
-        example.save!
-        suggestion.update!(processed: true)
-        question
-      end
-    end
-
-    private
-
-    attr_reader :suggestion, :user
-
-    def promoted_question
-      suggestion.gekanator_questions.order(id: :desc).first
-    end
-  end
-end

backend/config/routes.rb

@@ -63,24 +63,6 @@ Rails.application.routes.draw do
     end
   end
 
-  namespace :gekanator do
-    resources :games, only: [:create], controller: '/gekanator_games' do
-      member do
-        get :extra_questions
-        post :extra_question_answers
-      end
-    end
-    resources :posts, only: [:index], controller: '/gekanator_posts'
-    resources :questions, only: [:index], controller: '/gekanator_questions'
-    resources :question_suggestions,
-              only: [:create],
-              controller: '/gekanator_question_suggestions' do
-      member do
-        post :ai_convert
-      end
-    end
-  end
-
   resources :users, only: [:create, :update] do
     collection do
       post :verify

backend/db/migrate/20260607000000_create_gekanator_games.rb

@@ -1,18 +0,0 @@
-class CreateGekanatorGames < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_games do |t|
-      t.references :user, null: false, foreign_key: true
-      t.references :guessed_post, null: false, foreign_key: { to_table: :posts }
-      t.references :correct_post, null: false, foreign_key: { to_table: :posts }
-      t.boolean :won, null: false
-      t.integer :question_count, null: false
-      t.json :answers, null: false
-
-      t.timestamps
-    end
-
-    add_check_constraint :gekanator_games,
-                         'question_count >= 0',
-                         name: 'chk_gekanator_games_question_count_nonnegative'
-  end
-end

backend/db/migrate/20260608000000_create_gekanator_question_suggestions.rb

@@ -1,14 +0,0 @@
-class CreateGekanatorQuestionSuggestions < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_question_suggestions do |t|
-      t.references :gekanator_game,
-                   null: false,
-                   foreign_key: { on_delete: :cascade }
-      t.references :user, null: false, foreign_key: true
-      t.text :question_text, null: false
-      t.boolean :processed, null: false, default: false
-
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260608002000_add_answer_to_gekanator_question_suggestions.rb

@@ -1,5 +0,0 @@
-class AddAnswerToGekanatorQuestionSuggestions < ActiveRecord::Migration[8.0]
-  def change
-    add_column :gekanator_question_suggestions, :answer, :string, null: false
-  end
-end

backend/db/migrate/20260609000000_create_gekanator_questions.rb

@@ -1,19 +0,0 @@
-class CreateGekanatorQuestions < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_questions do |t|
-      t.string :text, null: false
-      t.string :kind, null: false
-      t.json :condition, null: false
-      t.string :source, null: false, default: 'ai_generated'
-      t.string :status, null: false, default: 'pending'
-      t.float :priority_weight, null: false, default: 1.0
-      t.references :gekanator_question_suggestion,
-                   null: true,
-                   foreign_key: true
-      t.references :created_by,
-                   null: true,
-                   foreign_key: { to_table: :users }
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260609001000_create_gekanator_ai_runs.rb

@@ -1,13 +0,0 @@
-class CreateGekanatorAiRuns < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_ai_runs do |t|
-      t.string :model, null: false
-      t.integer :input_tokens, null: false, default: 0
-      t.integer :output_tokens, null: false, default: 0
-      t.decimal :estimated_cost_jpy, precision: 8, scale: 3, null: false, default: 0
-      t.string :status, null: false, default: 'pending'
-      t.references :gekanator_question_suggestion, null: false, foreign_key: true
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260610000000_create_gekanator_question_examples.rb

@@ -1,19 +0,0 @@
-class CreateGekanatorQuestionExamples < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_question_examples do |t|
-      t.references :gekanator_question, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-      t.references :gekanator_game, null: true, foreign_key: true
-      t.string :answer, null: false
-      t.string :source, null: false, default: 'post_game_extra'
-      t.float :weight, null: false, default: 1.0
-      t.timestamps
-    end
-
-    add_index :gekanator_question_examples,
-              [:gekanator_question_id, :post_id, :user_id],
-              unique: true,
-              name: 'idx_gekanator_question_examples_on_question_post_user'
-  end
-end

backend/db/migrate/20260612000000_add_answer_statistics_to_gekanator_question_examples.rb

@@ -1,40 +0,0 @@
-class AddAnswerStatisticsToGekanatorQuestionExamples < ActiveRecord::Migration[8.0]
-  class MigrationGekanatorQuestionExample < ApplicationRecord
-    self.table_name = 'gekanator_question_examples'
-  end
-
-  def up
-    add_column :gekanator_question_examples,
-               :answer_counts,
-               :json,
-               null: true
-    add_column :gekanator_question_examples,
-               :sample_count,
-               :integer,
-               null: false,
-               default: 1
-
-    MigrationGekanatorQuestionExample.reset_column_information
-    MigrationGekanatorQuestionExample.find_each do |example|
-      counts = {
-        'yes' => 0,
-        'no' => 0,
-        'partial' => 0,
-        'probably_no' => 0,
-        'unknown' => 0
-      }
-      counts[example.answer] = 1 if counts.key?(example.answer)
-
-      example.update_columns(
-        answer_counts: counts,
-        sample_count: 1)
-    end
-
-    change_column_null :gekanator_question_examples, :answer_counts, false
-  end
-
-  def down
-    remove_column :gekanator_question_examples, :sample_count
-    remove_column :gekanator_question_examples, :answer_counts
-  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_06_12_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_06_06_000000) 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
@@ -48,79 +48,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.index ["tag_id"], name: "index_deerjikists_on_tag_id"
   end
 
-  create_table "gekanator_ai_runs", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.string "model", null: false
-    t.integer "input_tokens", default: 0, null: false
-    t.integer "output_tokens", default: 0, null: false
-    t.decimal "estimated_cost_jpy", precision: 8, scale: 3, default: "0.0", null: false
-    t.string "status", default: "pending", null: false
-    t.bigint "gekanator_question_suggestion_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["gekanator_question_suggestion_id"], name: "index_gekanator_ai_runs_on_gekanator_question_suggestion_id"
-  end
-
-  create_table "gekanator_games", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "user_id", null: false
-    t.bigint "guessed_post_id", null: false
-    t.bigint "correct_post_id", null: false
-    t.boolean "won", null: false
-    t.integer "question_count", null: false
-    t.json "answers", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["correct_post_id"], name: "index_gekanator_games_on_correct_post_id"
-    t.index ["guessed_post_id"], name: "index_gekanator_games_on_guessed_post_id"
-    t.index ["user_id"], name: "index_gekanator_games_on_user_id"
-    t.check_constraint "`question_count` >= 0", name: "chk_gekanator_games_question_count_nonnegative"
-  end
-
-  create_table "gekanator_question_examples", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "gekanator_question_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "user_id", null: false
-    t.bigint "gekanator_game_id"
-    t.string "answer", null: false
-    t.string "source", default: "post_game_extra", null: false
-    t.float "weight", default: 1.0, null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.json "answer_counts", null: false
-    t.integer "sample_count", default: 1, null: false
-    t.index ["gekanator_game_id"], name: "index_gekanator_question_examples_on_gekanator_game_id"
-    t.index ["gekanator_question_id", "post_id", "user_id"], name: "idx_gekanator_question_examples_on_question_post_user", unique: true
-    t.index ["gekanator_question_id"], name: "index_gekanator_question_examples_on_gekanator_question_id"
-    t.index ["post_id"], name: "index_gekanator_question_examples_on_post_id"
-    t.index ["user_id"], name: "index_gekanator_question_examples_on_user_id"
-  end
-
-  create_table "gekanator_question_suggestions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "gekanator_game_id", null: false
-    t.bigint "user_id", null: false
-    t.text "question_text", null: false
-    t.boolean "processed", default: false, null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.string "answer", null: false
-    t.index ["gekanator_game_id"], name: "index_gekanator_question_suggestions_on_gekanator_game_id"
-    t.index ["user_id"], name: "index_gekanator_question_suggestions_on_user_id"
-  end
-
-  create_table "gekanator_questions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.string "text", null: false
-    t.string "kind", null: false
-    t.json "condition", null: false
-    t.string "source", default: "ai_generated", null: false
-    t.string "status", default: "pending", null: false
-    t.float "priority_weight", default: 1.0, null: false
-    t.bigint "gekanator_question_suggestion_id"
-    t.bigint "created_by_id"
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["created_by_id"], name: "index_gekanator_questions_on_created_by_id"
-    t.index ["gekanator_question_suggestion_id"], name: "index_gekanator_questions_on_gekanator_question_suggestion_id"
-  end
-
   create_table "ip_addresses", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.binary "ip_address", limit: 16, null: false
     t.datetime "banned_at"
@@ -551,18 +478,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
-  add_foreign_key "gekanator_ai_runs", "gekanator_question_suggestions"
-  add_foreign_key "gekanator_games", "posts", column: "correct_post_id"
-  add_foreign_key "gekanator_games", "posts", column: "guessed_post_id"
-  add_foreign_key "gekanator_games", "users"
-  add_foreign_key "gekanator_question_examples", "gekanator_games"
-  add_foreign_key "gekanator_question_examples", "gekanator_questions"
-  add_foreign_key "gekanator_question_examples", "posts"
-  add_foreign_key "gekanator_question_examples", "users"
-  add_foreign_key "gekanator_question_suggestions", "gekanator_games", on_delete: :cascade
-  add_foreign_key "gekanator_question_suggestions", "users"
-  add_foreign_key "gekanator_questions", "gekanator_question_suggestions"
-  add_foreign_key "gekanator_questions", "users", column: "created_by_id"
   add_foreign_key "material_versions", "materials"
   add_foreign_key "material_versions", "materials", column: "parent_id"
   add_foreign_key "material_versions", "tags"

backend/spec/requests/gekanator_games_spec.rb

@@ -1,75 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'Gekanator games API', type: :request do
-  let!(:admin) { create_admin_user! }
-  let!(:user) { create_member_user! }
-  let!(:guessed_post) { Post.create!(title: 'guess', url: 'https://example.com/guess') }
-  let!(:correct_post) { Post.create!(title: 'correct', url: 'https://example.com/correct') }
-
-  describe 'POST /gekanator/games' do
-    it 'stores a won game' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [{ question_id: 'tag:1', answer: 'yes' }] }
-
-      expect(response).to have_http_status(:created)
-      game = GekanatorGame.find(json['id'])
-      expect(game.user).to eq(admin)
-      expect(game.guessed_post).to eq(guessed_post)
-      expect(game.correct_post).to eq(guessed_post)
-      expect(game.won).to eq(true)
-      expect(game.question_count).to eq(1)
-      expect(game.answers).to eq([{ 'question_id' => 'tag:1', 'answer' => 'yes' }])
-    end
-
-    it 'stores a lost game with the correct post' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: correct_post.id,
-          question_count: 4,
-          answers: [{ question_id: 'tag:1', answer: 'no' }] }
-
-      expect(response).to have_http_status(:created)
-      game = GekanatorGame.find(json['id'])
-      expect(game.correct_post).to eq(correct_post)
-      expect(game.won).to eq(false)
-      expect(game.question_count).to eq(1)
-    end
-
-    it 'rejects a game without the correct post' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          question_count: 4,
-          answers: [{ question_id: 'tag:1', answer: 'no' }] }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'returns not found without an admin user' do
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [] }
-
-      expect(response).to have_http_status(:not_found)
-    end
-
-    it 'returns not found for a non-admin user' do
-      sign_in_as user
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [{ question_id: 'tag:1', answer: 'yes' }] }
-
-      expect(response).to have_http_status(:not_found)
-    end
-  end
-end

backend/spec/requests/gekanator_learning_spec.rb

@@ -1,612 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'Gekanator learning API', type: :request do
-  let(:admin) { create(:user, :admin) }
-  let(:member) { create(:user, :member) }
-  let(:other_user) { create(:user, :member) }
-
-  let!(:guessed_post) do
-    Post.create!(
-      title: 'guessed',
-      url: 'https://example.com/guessed'
-    )
-  end
-
-  let!(:correct_post) do
-    Post.create!(
-      title: 'correct',
-      url: 'https://example.com/correct'
-    )
-  end
-
-  let!(:other_post) do
-    Post.create!(
-      title: 'other',
-      url: 'https://example.com/other'
-    )
-  end
-
-  let!(:game) do
-    GekanatorGame.create!(
-      user: admin,
-      guessed_post: guessed_post,
-      correct_post: correct_post,
-      won: false,
-      question_count: 1,
-      answers: [
-        {
-          'question_id' => 'tag:character:喜多郁代',
-          'question_text' => '喜多ちゃんが関係してる?',
-          'answer' => 'yes',
-          'original_answer' => 'yes'
-        }
-      ]
-    )
-  end
-
-  def create_post_similarity_question!(
-    text: '喜多ちゃんが泣いてる?',
-    post: correct_post,
-    answer: 'yes',
-    status: 'accepted',
-    source: 'user_suggested',
-    priority_weight: 1.2
-  )
-    GekanatorQuestion.create!(
-      text: text,
-      kind: 'post_similarity',
-      source: source,
-      status: status,
-      priority_weight: priority_weight,
-      condition: {
-        type: 'post-similarity',
-        postId: post.id,
-        answer: answer,
-        threshold: 0.65
-      },
-      created_by: admin
-    )
-  end
-
-  describe 'POST /gekanator/games' do
-    it 'stores a game result for an admin user' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-        guessed_post_id: guessed_post.id,
-        correct_post_id: correct_post.id,
-        answers: [
-          {
-            question_id: 'tag:character:喜多郁代',
-            question_text: '喜多ちゃんが関係してる?',
-            answer: 'yes',
-            original_answer: 'yes'
-          }
-        ]
-      }
-
-      expect(response).to have_http_status(:created)
-
-      created = GekanatorGame.find(json['id'])
-      expect(created.user).to eq(admin)
-      expect(created.guessed_post).to eq(guessed_post)
-      expect(created.correct_post).to eq(correct_post)
-      expect(created.won).to eq(false)
-      expect(created.question_count).to eq(1)
-      expect(created.answers).to eq([
-        {
-          'question_id' => 'tag:character:喜多郁代',
-          'question_text' => '喜多ちゃんが関係してる?',
-          'answer' => 'yes',
-          'original_answer' => 'yes'
-        }
-      ])
-    end
-
-    it 'stores a won game when guessed_post_id equals correct_post_id' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-        guessed_post_id: correct_post.id,
-        correct_post_id: correct_post.id,
-        answers: []
-      }
-
-      expect(response).to have_http_status(:created)
-      expect(GekanatorGame.find(json['id']).won).to eq(true)
-    end
-
-    it 'rejects a game without correct_post_id' do
-      sign_in_as admin
-
-      expect {
-        post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          answers: []
-        }
-      }.not_to change { GekanatorGame.count }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'returns not found for a non-admin user' do
-      sign_in_as member
-
-      post '/gekanator/games', params: {
-        guessed_post_id: guessed_post.id,
-        correct_post_id: correct_post.id,
-        answers: []
-      }
-
-      expect(response).to have_http_status(:not_found)
-    end
-  end
-
-  describe 'POST /gekanator/question_suggestions' do
-    it 'creates a suggestion and promotes yes answer to an accepted post_similarity question' do
-      sign_in_as admin
-
-      expect {
-        post '/gekanator/question_suggestions', params: {
-          gekanator_game_id: game.id,
-          question_text: '喜多ちゃんが泣いてる?',
-          answer: 'yes'
-        }
-      }.to change { GekanatorQuestionSuggestion.count }.by(1)
-        .and change { GekanatorQuestion.count }.by(1)
-        .and change { GekanatorQuestionExample.count }.by(1)
-
-      expect(response).to have_http_status(:created)
-
-      suggestion = GekanatorQuestionSuggestion.last
-      question = GekanatorQuestion.last
-      example = GekanatorQuestionExample.last
-
-      expect(json).to include(
-        'id' => suggestion.id,
-        'count' => 1
-      )
-
-      expect(suggestion).to have_attributes(
-        gekanator_game_id: game.id,
-        user_id: admin.id,
-        question_text: '喜多ちゃんが泣いてる?',
-        answer: 'yes',
-        processed: true
-      )
-
-      expect(question).to have_attributes(
-        text: '喜多ちゃんが泣いてる?',
-        kind: 'post_similarity',
-        source: 'user_suggested',
-        status: 'accepted',
-        priority_weight: 1.2,
-        gekanator_question_suggestion_id: suggestion.id,
-        created_by_id: admin.id
-      )
-      expect(question.condition).to include(
-        'type' => 'post-similarity',
-        'postId' => correct_post.id,
-        'answer' => 'yes',
-        'threshold' => 0.65
-      )
-
-      expect(example).to have_attributes(
-        gekanator_question_id: question.id,
-        post_id: correct_post.id,
-        user_id: admin.id,
-        gekanator_game_id: game.id,
-        answer: 'yes',
-        source: 'initial_suggestion',
-        weight: 1.0
-      )
-    end
-
-    it 'promotes no, partial, and probably_no answers' do
-      sign_in_as admin
-
-      ['no', 'partial', 'probably_no'].each do |answer|
-        expect {
-          post '/gekanator/question_suggestions', params: {
-            gekanator_game_id: game.id,
-            question_text: "answer #{answer} question?",
-            answer: answer
-          }
-        }.to change { GekanatorQuestion.count }.by(1)
-          .and change { GekanatorQuestionExample.count }.by(1)
-
-        expect(response).to have_http_status(:created)
-        expect(GekanatorQuestion.last.condition['answer']).to eq(answer)
-        expect(GekanatorQuestionExample.last.answer).to eq(answer)
-      end
-    end
-
-    it 'does not promote unknown answers' do
-      sign_in_as admin
-
-      expect {
-        post '/gekanator/question_suggestions', params: {
-          gekanator_game_id: game.id,
-          question_text: 'よく分からない質問?',
-          answer: 'unknown'
-        }
-      }.to change { GekanatorQuestionSuggestion.count }.by(1)
-        .and change { GekanatorQuestion.count }.by(0)
-        .and change { GekanatorQuestionExample.count }.by(0)
-
-      expect(response).to have_http_status(:created)
-      expect(GekanatorQuestionSuggestion.last.processed).to eq(false)
-    end
-
-    it 'limits suggestions to three per game' do
-      sign_in_as admin
-
-      3.times do |i|
-        GekanatorQuestionSuggestion.create!(
-          gekanator_game: game,
-          user: admin,
-          question_text: "existing question #{i}",
-          answer: 'unknown'
-        )
-      end
-
-      expect {
-        post '/gekanator/question_suggestions', params: {
-          gekanator_game_id: game.id,
-          question_text: 'fourth question?',
-          answer: 'yes'
-        }
-      }.not_to change { GekanatorQuestionSuggestion.count }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'returns not found for a non-admin user' do
-      sign_in_as member
-
-      post '/gekanator/question_suggestions', params: {
-        gekanator_game_id: game.id,
-        question_text: 'member question?',
-        answer: 'yes'
-      }
-
-      expect(response).to have_http_status(:not_found)
-    end
-  end
-
-  describe 'GET /gekanator/games/:id/extra_questions' do
-    it 'returns at most two accepted user_suggested post_similarity questions without duplicates' do
-      sign_in_as admin
-
-      low = create_post_similarity_question!(
-        text: 'low?',
-        priority_weight: 1.0
-      )
-      high = create_post_similarity_question!(
-        text: 'high?',
-        priority_weight: 3.0
-      )
-      middle = create_post_similarity_question!(
-        text: 'middle?',
-        priority_weight: 2.0
-      )
-
-      get "/gekanator/games/#{game.id}/extra_questions"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].length).to eq(2)
-      expect(json['questions'].map { _1['id'] }.uniq.length).to eq(2)
-      expect(json['questions'].map { _1['id'] }).to all(be_in([low.id, high.id, middle.id]))
-    end
-
-    it 'can return questions that already have an example for the correct post' do
-      sign_in_as admin
-
-      existing = create_post_similarity_question!(text: 'already learned?')
-
-      GekanatorQuestionExample.create!(
-        gekanator_question: existing,
-        post: correct_post,
-        user: admin,
-        gekanator_game: game,
-        answer: 'yes',
-        source: 'post_game_extra'
-      )
-
-      get "/gekanator/games/#{game.id}/extra_questions"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].map { _1['id'] }).to include(existing.id)
-    end
-
-    it 'can return questions already asked in the game using snake_case question_id' do
-      sign_in_as admin
-
-      asked = create_post_similarity_question!(text: 'already asked?')
-      game.update!(
-        answers: [
-          {
-            'question_id' => "post-similarity:#{asked.id}",
-            'answer' => 'yes'
-          }
-        ]
-      )
-
-      get "/gekanator/games/#{game.id}/extra_questions"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].map { _1['id'] }).to include(asked.id)
-    end
-
-    it 'can return questions already asked in the game using camelCase questionId' do
-      sign_in_as admin
-
-      asked = create_post_similarity_question!(text: 'already asked?')
-      game.update!(
-        answers: [
-          {
-            'questionId' => "post-similarity:#{asked.id}",
-            'answer' => 'yes'
-          }
-        ]
-      )
-
-      get "/gekanator/games/#{game.id}/extra_questions"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].map { _1['id'] }).to include(asked.id)
-    end
-
-    it 'does not return non-accepted, non-user_suggested, or non-post_similarity questions' do
-      sign_in_as admin
-
-      accepted = create_post_similarity_question!(text: 'accepted?')
-      create_post_similarity_question!(text: 'disabled?', status: 'disabled')
-      create_post_similarity_question!(text: 'ai?', source: 'ai_generated')
-      GekanatorQuestion.create!(
-        text: 'tag?',
-        kind: 'tag',
-        source: 'user_suggested',
-        status: 'accepted',
-        priority_weight: 1.0,
-        condition: { type: 'tag', key: 'character:喜多郁代' }
-      )
-
-      get "/gekanator/games/#{game.id}/extra_questions"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].map { _1['id'] }).to contain_exactly(accepted.id)
-    end
-  end
-
-  describe 'POST /gekanator/games/:id/extra_question_answers' do
-    it 'creates examples for extra question answers' do
-      sign_in_as admin
-
-      question = create_post_similarity_question!(text: 'extra?')
-
-      expect {
-        post "/gekanator/games/#{game.id}/extra_question_answers", params: {
-          answers: [
-            {
-              question_id: question.id.to_s,
-              answer: 'partial'
-            }
-          ]
-        }
-      }.to change { GekanatorQuestionExample.count }.by(1)
-
-      expect(response).to have_http_status(:created)
-      expect(json).to include('count' => 1)
-
-      example = GekanatorQuestionExample.last
-      expect(example).to have_attributes(
-        gekanator_question_id: question.id,
-        post_id: correct_post.id,
-        user_id: admin.id,
-        gekanator_game_id: game.id,
-        answer: 'partial',
-        source: 'post_game_extra',
-        weight: 1.0
-      )
-    end
-
-    it 'updates an existing example for the same question, post, and user' do
-      sign_in_as admin
-
-      question = create_post_similarity_question!(text: 'extra?')
-      existing = GekanatorQuestionExample.create!(
-        gekanator_question: question,
-        post: correct_post,
-        user: admin,
-        answer: 'no',
-        source: 'post_game_extra',
-        weight: 1.0
-      )
-
-      expect {
-        post "/gekanator/games/#{game.id}/extra_question_answers", params: {
-          answers: [
-            {
-              question_id: question.id,
-              answer: 'yes'
-            }
-          ]
-        }
-      }.not_to change { GekanatorQuestionExample.count }
-
-      expect(response).to have_http_status(:created)
-      expect(existing.reload).to have_attributes(
-        answer: 'yes',
-        source: 'post_game_extra',
-        gekanator_game_id: game.id
-      )
-    end
-
-    it 'rejects missing questions' do
-      sign_in_as admin
-
-      expect {
-        post "/gekanator/games/#{game.id}/extra_question_answers", params: {
-          answers: [
-            {
-              question_id: 999_999_999,
-              answer: 'yes'
-            }
-          ]
-        }
-      }.not_to change { GekanatorQuestionExample.count }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'rejects non-accepted questions' do
-      sign_in_as admin
-
-      question = create_post_similarity_question!(
-        text: 'disabled?',
-        status: 'disabled'
-      )
-
-      post "/gekanator/games/#{game.id}/extra_question_answers", params: {
-        answers: [
-          {
-            question_id: question.id,
-            answer: 'yes'
-          }
-        ]
-      }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'rejects non-post_similarity questions' do
-      sign_in_as admin
-
-      question = GekanatorQuestion.create!(
-        text: 'tag?',
-        kind: 'tag',
-        source: 'user_suggested',
-        status: 'accepted',
-        priority_weight: 1.0,
-        condition: { type: 'tag', key: 'character:喜多郁代' }
-      )
-
-      post "/gekanator/games/#{game.id}/extra_question_answers", params: {
-        answers: [
-          {
-            question_id: question.id,
-            answer: 'yes'
-          }
-        ]
-      }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-  end
-
-  describe 'GET /gekanator/questions' do
-    it 'returns accepted questions only and includes example_answers for post_similarity questions' do
-      sign_in_as admin
-
-      accepted = create_post_similarity_question!(text: 'accepted?')
-      create_post_similarity_question!(
-        text: 'disabled?',
-        status: 'disabled'
-      )
-
-      GekanatorQuestionExample.create!(
-        gekanator_question: accepted,
-        post: correct_post,
-        user: admin,
-        answer: 'yes',
-        source: 'initial_suggestion',
-        weight: 1.0
-      )
-
-      get '/gekanator/questions'
-
-      expect(response).to have_http_status(:ok)
-      expect(json['questions'].length).to eq(1)
-
-      question_json = json['questions'].first
-      expect(question_json).to include(
-        'id' => "post-similarity:#{accepted.id}",
-        'text' => 'accepted?',
-        'kind' => 'post_similarity',
-        'source' => 'user_suggested',
-        'priority_weight' => 1.2
-      )
-      expect(question_json['condition']).to include(
-        'type' => 'post-similarity',
-        'postId' => correct_post.id,
-        'answer' => 'yes',
-        'threshold' => 0.65
-      )
-      expect(question_json['example_answers']).to include(
-        correct_post.id.to_s => 'yes'
-      )
-    end
-
-    it 'aggregates example_answers by weight' do
-      sign_in_as admin
-
-      question = create_post_similarity_question!(text: 'weighted?')
-
-      GekanatorQuestionExample.create!(
-        gekanator_question: question,
-        post: other_post,
-        user: admin,
-        answer: 'yes',
-        source: 'post_game_extra',
-        weight: 1.0
-      )
-      GekanatorQuestionExample.create!(
-        gekanator_question: question,
-        post: other_post,
-        user: other_user,
-        answer: 'no',
-        source: 'post_game_extra',
-        weight: 2.0
-      )
-
-      get '/gekanator/questions'
-
-      expect(response).to have_http_status(:ok)
-      question_json = json['questions'].find { _1['id'] == "post-similarity:#{question.id}" }
-      expect(question_json['example_answers']).to include(
-        other_post.id.to_s => 'no'
-      )
-    end
-
-    it 'normalizes legacy title length questions' do
-      sign_in_as admin
-
-      GekanatorQuestion.create!(
-        text: '題名が長めの投稿?',
-        kind: 'title',
-        source: 'admin_curated',
-        status: 'accepted',
-        priority_weight: 1.0,
-        condition: {
-          type: 'title-length-greater-than',
-          length: 20
-        },
-        created_by: admin
-      )
-
-      get '/gekanator/questions'
-
-      expect(response).to have_http_status(:ok)
-      question_json = json['questions'].find { _1['id'] == 'title:length-at-least:21' }
-      expect(question_json).to include(
-        'text' => 'タイトルは 21 文字以上?',
-        'kind' => 'title'
-      )
-      expect(question_json['condition']).to include(
-        'type' => 'title-length-at-least',
-        'length' => 21
-      )
-    end
-  end
-end

frontend/AGENTS.md

@@ -33,10 +33,6 @@ npm run lint
 
 If either command cannot be run or fails, report the exact command and failure.
 
-Do not create, modify, or run tests unless the user explicitly asks for test
-work. When the user asks for tests, keep working and rerun them until they
-pass or the remaining failure is clearly blocked.
-
 ## TypeScript
 
 - TypeScript is strict. `tsconfig.app.json` enables `strict`,

frontend/src/App.tsx

@@ -18,7 +18,6 @@ import MaterialListPage from '@/pages/materials/MaterialListPage'
 import MaterialNewPage from '@/pages/materials/MaterialNewPage'
 // import MaterialSearchPage from '@/pages/materials/MaterialSearchPage'
 import MorePage from '@/pages/MorePage'
-import GekanatorPage from '@/pages/GekanatorPage'
 import NicoTagListPage from '@/pages/tags/NicoTagListPage'
 import NotFound from '@/pages/NotFound'
 import TOSPage from '@/pages/TOSPage.mdx'
@@ -40,7 +39,7 @@ import WikiHistoryPage from '@/pages/wiki/WikiHistoryPage'
 import WikiNewPage from '@/pages/wiki/WikiNewPage'
 import WikiSearchPage from '@/pages/wiki/WikiSearchPage'
 
-import type { Dispatch, FC, ReactNode, SetStateAction } from 'react'
+import type { Dispatch, FC, SetStateAction } from 'react'
 
 import type { User } from '@/types'
 
@@ -81,10 +80,6 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/users/settings" element={<SettingPage user={user} setUser={setUser}/>}/>
 	  <Route path="/settings" element={<Navigate to="/users/settings" replace/>}/>
 	  <Route path="/tos" element={<TOSPage/>}/>
-	  <Route path="/gekanator" element={
-	      <AdminOnly user={user}>
-		<GekanatorPage/>
-	      </AdminOnly>}/>
 	  <Route path="/more" element={<MorePage/>}/>
 	  <Route path="*" element={<NotFound/>}/>
 	</Routes>
@@ -92,16 +87,6 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 }
 
 
-const AdminOnly = ({ user, children }: {
-    user:      User | null
-    children:  ReactNode }) => {
-  if (user?.role !== 'admin')
-    return <NotFound/>
-
-  return <>{children}</>
-}
-
-
 const PostDetailRoute = ({ user }: { user: User | null }) => {
   const location = useLocation ()
   const key = location.pathname

frontend/src/components/NicoViewer.test.tsx

@@ -1,83 +0,0 @@
-import { act, fireEvent, render } from '@testing-library/react'
-import { afterEach, describe, expect, it, vi } from 'vitest'
-import { createRef } from 'react'
-
-import NicoViewer from '@/components/NicoViewer'
-
-import type { NiconicoViewerHandle } from '@/types'
-
-
-describe ('NicoViewer', () => {
-  afterEach (() => {
-    vi.useRealTimers ()
-  })
-
-  it ('does not time out after metadata reports a playable duration', () => {
-    vi.useFakeTimers ()
-
-    const onError = vi.fn ()
-    const onMetadataChange = vi.fn ()
-    const { container } = render (
-        <NicoViewer
-            id="sm12345"
-            width={640}
-            height={360}
-            onMetadataChange={onMetadataChange}
-            onError={onError}/>,
-    )
-    const iframe = container.querySelector ('iframe')
-    expect (iframe).not.toBeNull ()
-
-    fireEvent.load (iframe!)
-    act (() => {
-      window.dispatchEvent (new MessageEvent ('message', {
-        origin: 'https://embed.nicovideo.jp',
-        source: iframe!.contentWindow,
-        data:   {
-          eventName: 'playerMetadataChange',
-          data:      {
-            currentTime:           7,
-            duration:              120,
-            isVideoMetaDataLoaded: true,
-            maximumBuffered:       30,
-            muted:                 false,
-            showComment:           true,
-            volume:                1,
-          },
-        },
-      }))
-    })
-
-    act (() => {
-      vi.advanceTimersByTime (8_000)
-    })
-
-    expect (onMetadataChange).toHaveBeenCalled ()
-    expect (onError).not.toHaveBeenCalled ()
-  })
-
-  it ('seeks with milliseconds', () => {
-    const ref = createRef<NiconicoViewerHandle> ()
-    const { container } = render (
-        <NicoViewer
-            ref={ref}
-            id="sm12345"
-            width={640}
-            height={360}/>,
-    )
-    const iframe = container.querySelector ('iframe')!
-    const postMessage = vi.spyOn (iframe.contentWindow!, 'postMessage')
-
-    act (() => {
-      ref.current!.seek (7_000)
-    })
-
-    expect (postMessage).toHaveBeenCalledWith (
-        expect.objectContaining ({
-          eventName: 'seek',
-          data:      { time: 7_000 },
-        }),
-        'https://embed.nicovideo.jp',
-    )
-  })
-})

frontend/src/components/NicoViewer.tsx

@@ -129,9 +129,7 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
   }, [playerId, postToPlayer])
 
   const seek = useCallback ((time: number) => {
-    postToPlayer (
+    postToPlayer ({ eventName: 'seek', sourceConnectorType: 1, playerId, data: { time } })
-	{ eventName: 'seek', sourceConnectorType: 1, playerId,
-	  data: { time } })
   }, [playerId, postToPlayer])
 
   const mute = useCallback (() => {
@@ -204,9 +202,6 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
 
       if (data.eventName === 'playerMetadataChange')
 	{
-	  if (Number.isFinite (data.data.duration) && data.data.duration > 0)
-	    clearLoadCompleteTimer ()
-
 	  onMetadataChange?.(data.data)
 	  return
 	}

frontend/src/components/PostEmbed.test.tsx

@@ -8,19 +8,12 @@ const dialogue = vi.hoisted (() => ({
   confirm: vi.fn (),
 }))
 
-const nicoViewer = vi.hoisted (() => ({
-  props: vi.fn (),
-}))
-
 vi.mock ('@/components/dialogues/DialogueProvider', () => ({
   useDialogue: () => dialogue,
 }))
 
 vi.mock ('@/components/NicoViewer', () => ({
-  default: (props: { id: string }) => {
+  default: ({ id }: { id: string }) => <div>Nico:{id}</div>,
-    nicoViewer.props (props)
-    return <div>Nico:{props.id}</div>
-  },
 }))
 
 vi.mock ('react-youtube', () => ({
@@ -38,64 +31,6 @@ describe ('PostEmbed', () => {
     expect (screen.getByText ('Nico:sm12345')).toBeInTheDocument ()
   })
 
-  it ('reports niconico metadata as milliseconds', () => {
-    const onVideoReady = vi.fn ()
-    const onPlaybackChange = vi.fn ()
-    render (
-        <PostEmbed
-            post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}
-            onVideoReady={onVideoReady}
-            onPlaybackChange={onPlaybackChange}/>,
-    )
-
-    nicoViewer.props.mock.calls[0][0].onMetadataChange ({
-      currentTime:            7_000,
-      duration:               120_000,
-      isVideoMetaDataLoaded:  true,
-      maximumBuffered:        30,
-      muted:                  false,
-      showComment:            true,
-      volume:                 1,
-    })
-
-    expect (onVideoReady).toHaveBeenCalledWith (120_000)
-    expect (onPlaybackChange).toHaveBeenCalledWith (7_000)
-  })
-
-  it ('reports niconico video readiness only once', () => {
-    const onVideoReady = vi.fn ()
-    render (
-        <PostEmbed
-            post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}
-            onVideoReady={onVideoReady}/>,
-    )
-
-    nicoViewer.props.mock.calls[0][0].onLoadComplete ({
-      title:           '動画',
-      videoId:         'sm12345',
-      lengthInSeconds: 120,
-      thumbnailUrl:    'https://example.com/thumb.jpg',
-      description:     '',
-      viewCount:       1,
-      commentCount:    2,
-      mylistCount:     3,
-      postedAt:        '2026-01-02T03:04:05.000Z',
-      watchId:         12345,
-    })
-    nicoViewer.props.mock.calls[0][0].onMetadataChange ({
-      currentTime:            7_000,
-      duration:               120_000,
-      isVideoMetaDataLoaded:  true,
-      maximumBuffered:        30,
-      muted:                  false,
-      showComment:            true,
-      volume:                 1,
-    })
-
-    expect (onVideoReady).toHaveBeenCalledTimes (1)
-    expect (onVideoReady).toHaveBeenCalledWith (120_000)
-  })
-
   it ('embeds x/twitter status URLs', () => {
     render (<PostEmbed post={buildPost ({ url: 'https://x.com/someone/status/12345' })}/>)
 

frontend/src/components/PostEmbed.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useCallback, useEffect, useState } from 'react'
 import YoutubeEmbed from 'react-youtube'
 
 import NicoViewer from '@/components/NicoViewer'
@@ -36,17 +36,6 @@ const PostEmbed: FC<Props> = ({
   const dialogue = useDialogue ()
   const [framed, setFramed] = useState (false)
   const [youtubePlayer, setYoutubePlayer] = useState<YouTubePlayer | null> (null)
-  const niconicoVideoReadyRef = useRef (false)
-
-  const notifyNiconicoVideoReady = useCallback ((durationMs: number) => {
-    if (niconicoVideoReadyRef.current
-	|| !(Number.isFinite (durationMs))
-	|| durationMs <= 0)
-      return
-
-    niconicoVideoReadyRef.current = true
-    onVideoReady?.(durationMs)
-  }, [onVideoReady])
 
   const reportYoutubePlayback = useCallback (async (player: YouTubePlayer) => {
     const currentTime = await player.getCurrentTime ()
@@ -91,20 +80,15 @@ const PostEmbed: FC<Props> = ({
   }
 
   const handleNiconicoLoadComplete = (info: NiconicoVideoInfo) => {
-    notifyNiconicoVideoReady (info.lengthInSeconds * 1_000)
+    onVideoReady?.(info.lengthInSeconds * 1_000)
     onLoadComplete?.(info)
   }
 
   const handleNiconicoMetadataChange = (meta: NiconicoMetadata) => {
-    notifyNiconicoVideoReady (meta.duration)
     onPlaybackChange?.(meta.currentTime)
     onMetadataChange?.(meta)
   }
 
-  useEffect (() => {
-    niconicoVideoReadyRef.current = false
-  }, [post.url])
-
   useEffect (() => {
     if (!(youtubePlayer) || !(onPlaybackChange))
       return

frontend/src/lib/gekanator.test.ts

@@ -1,375 +0,0 @@
-import { beforeEach, describe, expect, it, vi } from 'vitest'
-
-import { apiPost } from '@/lib/api'
-import {
-  buildGekanatorQuestions,
-  expectedAnswerForQuestion,
-  restoreGekanatorQuestion,
-  saveGekanatorExtraQuestionAnswers,
-  saveGekanatorGame,
-  saveGekanatorQuestionSuggestion,
-} from '@/lib/gekanator'
-
-import type {
-  GekanatorAnswerLog,
-  StoredGekanatorQuestion,
-} from '@/lib/gekanator'
-import type { Post } from '@/types'
-
-vi.mock('@/lib/api', () => ({
-  apiGet: vi.fn(),
-  apiPost: vi.fn(),
-}))
-
-const mockedApiPost = vi.mocked(apiPost)
-
-const post = (overrides: Partial<Post> = {}): Post => ({
-  id: 1,
-  versionNo: 1,
-  url: 'https://example.com/posts/1',
-  title: 'post title',
-  thumbnail: null,
-  thumbnailBase: null,
-  tags: [],
-  viewed: false,
-  related: [],
-  originalCreatedFrom: null,
-  originalCreatedBefore: null,
-  createdAt: '2026-06-10T00:00:00.000Z',
-  updatedAt: '2026-06-10T00:00:00.000Z',
-  uploadedUser: null,
-  ...overrides,
-})
-
-describe('expectedAnswerForQuestion', () => {
-  it('returns a direct example answer when present', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'post-similarity:10',
-      text: '喜多ちゃんが泣いてる?',
-      kind: 'post_similarity',
-      source: 'user_suggested',
-      priorityWeight: 1.2,
-      condition: {
-        type: 'post-similarity',
-        postId: 999,
-        answer: 'yes',
-        threshold: 0.65,
-      },
-      exampleAnswers: {
-        1: 'partial',
-      },
-    }
-
-    expect(expectedAnswerForQuestion(question, post({ id: 1 }))).toBe('partial')
-  })
-
-  it('returns the condition answer for the original post_similarity post', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'post-similarity:10',
-      text: '喜多ちゃんが泣いてる?',
-      kind: 'post_similarity',
-      source: 'user_suggested',
-      priorityWeight: 1.2,
-      condition: {
-        type: 'post-similarity',
-        postId: 123,
-        answer: 'probably_no',
-        threshold: 0.65,
-      },
-    }
-
-    expect(expectedAnswerForQuestion(question, post({ id: 123 }))).toBe('probably_no')
-  })
-
-  it('returns null for an unrelated post_similarity post without examples', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'post-similarity:10',
-      text: '喜多ちゃんが泣いてる?',
-      kind: 'post_similarity',
-      source: 'user_suggested',
-      priorityWeight: 1.2,
-      condition: {
-        type: 'post-similarity',
-        postId: 123,
-        answer: 'yes',
-        threshold: 0.65,
-      },
-    }
-
-    expect(expectedAnswerForQuestion(question, post({ id: 456 }))).toBeNull()
-  })
-
-  it('returns yes for a matching tag question', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'tag:character:喜多郁代',
-      text: '喜多ちゃんが関係してる?',
-      kind: 'tag',
-      condition: {
-        type: 'tag',
-        key: 'character:喜多郁代',
-      },
-    }
-
-    expect(
-      expectedAnswerForQuestion(
-        question,
-        post({
-          tags: [
-            {
-              id: 1,
-              name: '喜多郁代',
-              category: 'character',
-              aliases: [],
-              parents: [],
-              postCount: 1,
-              createdAt: '2026-06-10T00:00:00.000Z',
-              updatedAt: '2026-06-10T00:00:00.000Z',
-              hasWiki: false,
-              hasDeerjikists: false,
-              materialId: null,
-            },
-          ],
-        }),
-      ),
-    ).toBe('yes')
-  })
-
-  it('returns no for a non-matching tag question', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'tag:character:喜多郁代',
-      text: '喜多ちゃんが関係してる?',
-      kind: 'tag',
-      condition: {
-        type: 'tag',
-        key: 'character:喜多郁代',
-      },
-    }
-
-    expect(expectedAnswerForQuestion(question, post({ tags: [] }))).toBe('no')
-  })
-
-  it('ignores example answers for direct title facts', () => {
-    const question: StoredGekanatorQuestion = {
-      id: 'title:length-at-least:20',
-      text: 'タイトルは 20 文字以上?',
-      kind: 'title',
-      condition: {
-        type: 'title-length-at-least',
-        length: 20,
-      },
-      exampleAnswers: {
-        1: 'yes',
-      },
-    }
-
-    expect(expectedAnswerForQuestion(question, post({ id: 1, title: 'short' }))).toBe('no')
-  })
-})
-
-describe('restoreGekanatorQuestion', () => {
-  it('uses default source and priority weight when omitted', () => {
-    const question = restoreGekanatorQuestion({
-      id: 'tag:character:喜多郁代',
-      text: '喜多ちゃんが関係してる?',
-      kind: 'tag',
-      condition: {
-        type: 'tag',
-        key: 'character:喜多郁代',
-      },
-    })
-
-    expect(question.source).toBe('default')
-    expect(question.priorityWeight).toBe(1)
-  })
-
-  it('tests a post_similarity question using direct examples', () => {
-    const question = restoreGekanatorQuestion({
-      id: 'post-similarity:10',
-      text: '喜多ちゃんが泣いてる?',
-      kind: 'post_similarity',
-      source: 'user_suggested',
-      priorityWeight: 1.2,
-      condition: {
-        type: 'post-similarity',
-        postId: 999,
-        answer: 'yes',
-        threshold: 0.65,
-      },
-      exampleAnswers: {
-        1: 'yes',
-        2: 'no',
-      },
-    })
-
-    expect(question.test(post({ id: 1 }))).toBe(true)
-    expect(question.test(post({ id: 2 }))).toBe(false)
-    expect(question.test(post({ id: 3 }))).toBe(false)
-  })
-
-  it('tests a post_similarity question against its configured partial answer', () => {
-    const question = restoreGekanatorQuestion({
-      id: 'post-similarity:10',
-      text: '喜多ちゃんが泣いてる?',
-      kind: 'post_similarity',
-      source: 'user_suggested',
-      priorityWeight: 1.2,
-      condition: {
-        type: 'post-similarity',
-        postId: 999,
-        answer: 'partial',
-        threshold: 0.65,
-      },
-      exampleAnswers: {
-        1: 'partial',
-        2: 'yes',
-      },
-    })
-
-    expect(question.test(post({ id: 1 }))).toBe(true)
-    expect(question.test(post({ id: 2 }))).toBe(false)
-  })
-
-  it('normalizes legacy title-length-greater-than questions', () => {
-    const question = restoreGekanatorQuestion({
-      id: 'title:length-greater-than:20',
-      text: '題名が長めの投稿?',
-      kind: 'title',
-      condition: {
-        type: 'title-length-greater-than',
-        length: 20,
-      },
-    })
-
-    expect(question.id).toBe('title:length-at-least:21')
-    expect(question.condition).toEqual({
-      type: 'title-length-at-least',
-      length: 21,
-    })
-    expect(question.test(post({ title: 'x'.repeat(20) }))).toBe(false)
-    expect(question.test(post({ title: 'x'.repeat(21) }))).toBe(true)
-  })
-})
-
-describe('buildGekanatorQuestions', () => {
-  it('builds quantitative title length questions', () => {
-    const questions = buildGekanatorQuestions([
-      post({ id: 1, title: 'a' }),
-      post({ id: 2, title: 'bb' }),
-      post({ id: 3, title: 'ccc' }),
-      post({ id: 4, title: 'dddd' }),
-    ])
-    const titleQuestion = questions.find(question =>
-      question.condition.type === 'title-length-at-least')
-
-    expect(titleQuestion?.text).toMatch(/^タイトルは \d+ 文字以上\?$/)
-    expect(titleQuestion?.id).toMatch(/^title:length-at-least:\d+$/)
-  })
-})
-
-describe('Gekanator API writers', () => {
-  beforeEach(() => {
-    mockedApiPost.mockReset()
-  })
-
-  it('sends game results using snake_case request keys', async () => {
-    mockedApiPost.mockResolvedValue({ id: 100 })
-
-    const answers: GekanatorAnswerLog[] = [
-      {
-        questionId: 'tag:character:喜多郁代',
-        questionText: '喜多ちゃんが関係してる?',
-        questionCondition: {
-          type: 'tag',
-          key: 'character:喜多郁代',
-        },
-        answer: 'yes',
-        originalAnswer: 'partial',
-      },
-    ]
-
-    await expect(
-      saveGekanatorGame({
-        guessedPostId: 1,
-        correctPostId: 2,
-        answers,
-      }),
-    ).resolves.toEqual({ id: 100 })
-
-    expect(mockedApiPost).toHaveBeenCalledWith('/gekanator/games', {
-      guessed_post_id: 1,
-      correct_post_id: 2,
-      answers: [
-        {
-          question_id: 'tag:character:喜多郁代',
-          question_text: '喜多ちゃんが関係してる?',
-          question_condition: {
-            type: 'tag',
-            key: 'character:喜多郁代',
-          },
-          answer: 'yes',
-          original_answer: 'partial',
-        },
-      ],
-    })
-  })
-
-  it('sends question suggestions using snake_case request keys', async () => {
-    mockedApiPost.mockResolvedValue({
-      id: 10,
-      count: 1,
-    })
-
-    await expect(
-      saveGekanatorQuestionSuggestion({
-        gekanatorGameId: 100,
-        questionText: '喜多ちゃんが泣いてる?',
-        answer: 'yes',
-      }),
-    ).resolves.toEqual({
-      id: 10,
-      count: 1,
-    })
-
-    expect(mockedApiPost).toHaveBeenCalledWith('/gekanator/question_suggestions', {
-      gekanator_game_id: 100,
-      question_text: '喜多ちゃんが泣いてる?',
-      answer: 'yes',
-    })
-  })
-
-  it('sends extra question answers using snake_case request keys', async () => {
-    mockedApiPost.mockResolvedValue({
-      count: 2,
-    })
-
-    await saveGekanatorExtraQuestionAnswers({
-      gameId: 100,
-      answers: [
-        {
-          questionId: 10,
-          answer: 'yes',
-        },
-        {
-          questionId: 11,
-          answer: 'probably_no',
-        },
-      ],
-    })
-
-    expect(mockedApiPost).toHaveBeenCalledWith(
-      '/gekanator/games/100/extra_question_answers',
-      {
-        answers: [
-          {
-            question_id: 10,
-            answer: 'yes',
-          },
-          {
-            question_id: 11,
-            answer: 'probably_no',
-          },
-        ],
-      },
-    )
-  })
-})

frontend/src/lib/gekanator.ts

@@ -1,564 +0,0 @@
-import { apiGet, apiPost } from '@/lib/api'
-
-import type { Post } from '@/types'
-
-export type GekanatorAnswerValue =
-    | 'yes'
-    | 'no'
-    | 'partial'
-    | 'probably_no'
-    | 'unknown'
-
-export type GekanatorAnswerLog = {
-    questionId:       string
-    questionText:     string
-    questionCondition?:  GekanatorQuestionCondition
-    answer:           GekanatorAnswerValue
-    originalAnswer:   GekanatorAnswerValue }
-
-export type GekanatorQuestionKind =
-    | 'tag'
-    | 'source'
-    | 'title'
-    | 'original_date'
-    | 'post_similarity'
-
-export type GekanatorQuestionSource =
-    | 'default'
-    | 'user_suggested'
-    | 'ai_generated'
-    | 'admin_curated'
-
-export type GekanatorQuestionCondition =
-    | { type: 'tag'; key: string }
-    | { type: 'source'; host: string }
-    | { type: 'original-year'; year: number }
-    | { type: 'original-month'; month: number }
-    | { type: 'original-month-day'; monthDay: string }
-    | { type: 'title-length-at-least'; length: number }
-    | { type: 'title-length-greater-than'; length: number }
-    | { type: 'title-has-ascii' }
-    | {
-	  type: 'post-similarity'
-	  postId: number
-	  answer: GekanatorAnswerValue
-	  threshold: number
-      }
-
-
-type NonPostSimilarityCondition = Exclude<
-    GekanatorQuestionCondition,
-    { type: 'post-similarity' }
->
-
-export type GekanatorExtraQuestion = {
-    id:              number
-    text:            string
-    source:          GekanatorQuestionSource
-    priorityWeight:  number }
-
-export type StoredGekanatorQuestion = {
-    id:              string
-    text:            string
-    kind:            GekanatorQuestionKind
-    condition:       GekanatorQuestionCondition
-    source?:         GekanatorQuestionSource
-    priorityWeight?: number
-    exampleAnswers?: Record<`${ number }`, GekanatorAnswerValue> }
-
-export type GekanatorQuestion = {
-    id:              string
-    text:            string
-    kind:            GekanatorQuestionKind
-    condition:       GekanatorQuestionCondition
-    source:          GekanatorQuestionSource
-    priorityWeight:  number
-    exampleAnswers?: Record<`${ number }`, GekanatorAnswerValue>
-    test:            (post: Post) => boolean }
-
-
-export const normalizeTitleLengthCondition = (
-    condition:  GekanatorQuestionCondition,
-): GekanatorQuestionCondition => {
-  switch (condition.type)
-  {
-  case 'title-length-greater-than':
-    return {
-	type:   'title-length-at-least',
-	length: condition.length + 1 }
-  default:
-    return condition
-  }
-}
-
-
-export const titleLengthMinimumForCondition = (
-    condition:  GekanatorQuestionCondition,
-): number | null => {
-  switch (condition.type)
-  {
-  case 'title-length-at-least':
-    return condition.length
-  case 'title-length-greater-than':
-    return condition.length + 1
-  default:
-    return null
-  }
-}
-
-
-export const questionIdForCondition = (
-    condition:  NonPostSimilarityCondition,
-): string => {
-  switch (condition.type)
-  {
-  case 'tag':
-    return `tag:${ condition.key }`
-  case 'source':
-    return `source:${ condition.host }`
-  case 'original-year':
-    return `original-year:${ condition.year }`
-  case 'original-month':
-    return `original-month:${ condition.month }`
-  case 'original-month-day':
-    return `original-month-day:${ condition.monthDay }`
-  case 'title-length-at-least':
-  case 'title-length-greater-than':
-    return `title:length-at-least:${ titleLengthMinimumForCondition (condition) }`
-  case 'title-has-ascii':
-    return 'title:ascii'
-  }
-}
-
-
-const directExampleAnswerFor = (
-    question:  StoredGekanatorQuestion,
-    post:      Post,
-): GekanatorAnswerValue | null => {
-  if (question.kind !== 'post_similarity')
-    return null
-
-  const direct = question.exampleAnswers?.[String (post.id) as `${ number }`]
-  if (direct)
-    return direct
-
-  if (question.condition.type === 'post-similarity' && question.condition.postId === post.id)
-    return question.condition.answer
-
-  return null
-}
-
-const countBy = <T extends string | number> (values: T[]): Map<T, number> => {
-  const counts = new Map<T, number> ()
-  values.forEach (value => counts.set (value, (counts.get (value) ?? 0) + 1))
-  return counts
-}
-
-
-const median = (values: number[]): number => {
-  const sorted = [...values].sort ((a, b) => a - b)
-  return sorted[Math.floor (sorted.length / 2)] ?? 0
-}
-
-
-const hostOf = (post: Post): string | null => {
-  try
-  {
-    return new URL (post.url).hostname.replace (/^www\./, '')
-  }
-  catch
-  {
-    return null
-  }
-}
-
-
-const originalYearOf = (post: Post): number | null => {
-  const value = post.originalCreatedFrom || post.originalCreatedBefore
-  if (!(value))
-    return null
-
-  const date = new Date (value)
-  if (Number.isNaN (date.getTime ()))
-    return null
-
-  return date.getFullYear ()
-}
-
-
-const originalDateOf = (post: Post): Date | null => {
-  const value = post.originalCreatedFrom || post.originalCreatedBefore
-  if (!(value))
-    return null
-
-  const date = new Date (value)
-  if (Number.isNaN (date.getTime ()))
-    return null
-
-  return date
-}
-
-
-const originalMonthOf = (post: Post): number | null => {
-  const date = originalDateOf (post)
-  if (!(date))
-    return null
-
-  return date.getMonth () + 1
-}
-
-
-const originalMonthDayOf = (post: Post): string | null => {
-  const date = originalDateOf (post)
-  if (!(date))
-    return null
-
-  return `${ date.getMonth () + 1 }-${ date.getDate () }`
-}
-
-
-const tagQuestionKey = ({ category, name }: { category: string; name: string }): string =>
-    `${ category }:${ name }`
-
-
-const tagFromQuestionKey = (key: string): { category: string; name: string } => {
-  const [category, ...rest] = key.split (':')
-  return { category: category ?? '', name: rest.join (':') }
-}
-
-
-const nicoTagLabel = (name: string): string => name.replace (/^nico:/, '')
-
-
-const tagQuestionText = (category: string, label: string): string => {
-  switch (category)
-  {
-  case 'deerjikist':
-    return `作者・ニジラーとして「${ label }」に関係してゐる?`
-  case 'meme':
-    return `元ネタ・ミームとして「${ label }」に関係しさう?`
-  case 'character':
-    return `「${ label }」といふキャラクターが関係してゐる?`
-  case 'material':
-    return `素材として「${ label }」に関係してゐる?`
-  case 'nico':
-    return `ニコニコに「${ label }」といふタグが付いてゐる?`
-  case 'general':
-  case 'meta':
-  default:
-    return `内容として「${ label }」に関係しさう?`
-  }
-}
-
-
-const questionableTag = (post: Post, key: string): boolean => {
-  const { category, name } = tagFromQuestionKey (key)
-
-  return (
-    post.tags.some (tag =>
-	tag.name === name
-	&& tag.category === category
-	&& !(tag.category === 'meta')
-	&& !(tag.name.includes ('タグ希望'))
-	&& !(tag.name.includes ('bot操作'))))
-}
-
-
-const questionMatches = (
-    post:       Post,
-    question:   StoredGekanatorQuestion,
-): boolean => {
-  const directAnswer = directExampleAnswerFor (question, post)
-  if (directAnswer)
-    return question.condition.type === 'post-similarity'
-	? directAnswer === question.condition.answer
-	: directAnswer === 'yes'
-
-  switch (question.condition.type)
-  {
-  case 'tag':
-    return questionableTag (post, question.condition.key)
-  case 'source':
-    return hostOf (post) === question.condition.host
-  case 'original-year':
-    return originalYearOf (post) === question.condition.year
-  case 'original-month':
-    return originalMonthOf (post) === question.condition.month
-  case 'original-month-day':
-    return originalMonthDayOf (post) === question.condition.monthDay
-  case 'title-length-at-least':
-    return (post.title?.length ?? 0) >= question.condition.length
-  case 'title-length-greater-than':
-    return (post.title?.length ?? 0) > question.condition.length
-  case 'title-has-ascii':
-    return /[A-Za-z0-9]/.test (post.title ?? '')
-  case 'post-similarity':
-    return false
-  }
-}
-
-
-export const expectedAnswerForQuestion = (
-    question:  StoredGekanatorQuestion | GekanatorQuestion | undefined,
-    post:      Post | null,
-): GekanatorAnswerValue | null => {
-  if (!(question) || !(post))
-    return null
-
-  const directAnswer = directExampleAnswerFor (question, post)
-  if (directAnswer)
-    return directAnswer
-
-  switch (question.condition.type)
-  {
-  case 'tag':
-  case 'source':
-  case 'original-year':
-  case 'original-month':
-  case 'original-month-day':
-  case 'title-length-at-least':
-  case 'title-length-greater-than':
-  case 'title-has-ascii':
-    return questionMatches (post, question) ? 'yes' : 'no'
-  case 'post-similarity':
-    return null
-  }
-}
-
-
-export const restoreGekanatorQuestion = (
-    question:  StoredGekanatorQuestion,
-): GekanatorQuestion => {
-  const normalizedCondition = normalizeTitleLengthCondition (question.condition)
-  const normalizedQuestion = {
-      ...question,
-      id: normalizedCondition.type === 'title-length-at-least'
-	  ? `title:length-at-least:${ normalizedCondition.length }`
-	  : question.id,
-      condition: normalizedCondition,
-      source: question.source ?? 'default',
-      priorityWeight: question.priorityWeight ?? 1 }
-
-  return {
-      ...normalizedQuestion,
-      test: (post: Post) => questionMatches (post, normalizedQuestion) }
-}
-
-
-export const storeGekanatorQuestion = (
-    question:  GekanatorQuestion,
-): StoredGekanatorQuestion => ({
-  id: question.condition.type === 'title-length-greater-than'
-      ? `title:length-at-least:${ question.condition.length + 1 }`
-      : question.id,
-  text: question.text,
-  kind: question.kind,
-  condition: normalizeTitleLengthCondition (question.condition),
-  source: question.source,
-  priorityWeight: question.priorityWeight,
-  exampleAnswers: question.exampleAnswers })
-
-
-export const fetchGekanatorPosts = async (): Promise<Post[]> => {
-  const data = await apiGet<{ posts: Post[] }> ('/gekanator/posts')
-  return data.posts
-}
-
-
-export const fetchGekanatorQuestions = async (): Promise<StoredGekanatorQuestion[]> => {
-  const data = await apiGet<{ questions: StoredGekanatorQuestion[] }> ('/gekanator/questions')
-  return data.questions
-}
-
-
-export const fetchGekanatorExtraQuestions = async (
-    gameId:  number,
-    nonce?: string,
-): Promise<GekanatorExtraQuestion[]> => {
-  const data = await apiGet<{ questions: GekanatorExtraQuestion[] }> (
-      `/gekanator/games/${ gameId }/extra_questions`,
-      { params: nonce ? { nonce } : undefined })
-  return data.questions
-}
-
-
-export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
-  const tagCounts = countBy (posts.flatMap (post =>
-      post.tags
-      .filter (tag =>
-	  !(tag.category === 'meta')
-	  && !(tag.name.includes ('タグ希望'))
-	  && !(tag.name.includes ('bot操作')))
-      .map (tag => tagQuestionKey (tag))))
-  const hosts = countBy (posts.map (hostOf).filter ((host): host is string => Boolean (host)))
-  const originalYears = countBy (
-      posts
-      .map (originalYearOf)
-      .filter ((year): year is number => year !== null))
-  const originalMonths = countBy (
-      posts
-      .map (originalMonthOf)
-      .filter ((month): month is number => month !== null))
-  const originalMonthDays = countBy (
-      posts
-      .map (originalMonthDayOf)
-      .filter ((monthDay): monthDay is string => monthDay !== null))
-  const titleLengthMedian = median (posts.map (post => post.title?.length ?? 0))
-
-  const usefulEntries = <T extends string | number> (counts: Map<T, number>) =>
-      [...counts.entries ()]
-      .filter (([, count]) => count > 0 && count < posts.length)
-      .sort ((a, b) => Math.abs (posts.length / 2 - a[1])
-	       - Math.abs (posts.length / 2 - b[1]))
-      .slice (0, 80)
-
-  const tagQuestions = usefulEntries (tagCounts)
-      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
-      .slice (0, 80)
-      .map (([key]) => {
-	const { category, name } = tagFromQuestionKey (String (key))
-	const label = category === 'nico' ? nicoTagLabel (name) : name
-
-	return {
-	    id:   `tag:${ key }`,
-	    text: tagQuestionText (category, label),
-	    kind: 'tag' as const,
-	    condition: { type: 'tag' as const, key: String (key) },
-	    source: 'default' as const,
-	    priorityWeight: 1,
-	    test: (post: Post) => questionableTag (post, String (key)) }
-      })
-
-  const sourceQuestions = usefulEntries (hosts)
-      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
-      .slice (0, 20)
-      .map (([host]) => ({
-	  id:   `source:${ host }`,
-	  text: `${ host } の投稿を思ひ浮かべてゐる?`,
-	  kind: 'source' as const,
-	  condition: { type: 'source' as const, host },
-	  source: 'default' as const,
-	  priorityWeight: 1,
-	  test: (post: Post) => hostOf (post) === host }))
-
-  const originalYearQuestions = usefulEntries (originalYears)
-      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
-      .slice (0, 20)
-      .map (([year]) => ({
-	  id:   `original-year:${ year }`,
-	  text: `オリジナルの投稿年は ${ year } 年?`,
-	  kind: 'original_date' as const,
-	  condition: { type: 'original-year' as const, year },
-	  source: 'default' as const,
-	  priorityWeight: 1,
-	  test: (post: Post) => originalYearOf (post) === year }))
-
-  const originalMonthQuestions = usefulEntries (originalMonths)
-      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
-      .slice (0, 20)
-      .map (([month]) => ({
-	  id:   `original-month:${ month }`,
-	  text: `オリジナルの投稿月は ${ month } 月?`,
-	  kind: 'original_date' as const,
-	  condition: { type: 'original-month' as const, month },
-	  source: 'default' as const,
-	  priorityWeight: 1,
-	  test: (post: Post) => originalMonthOf (post) === month }))
-
-  const originalMonthDayQuestions = usefulEntries (originalMonthDays)
-      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
-      .slice (0, 20)
-      .map (([monthDay]) => {
-	const [month, day] = String (monthDay).split ('-')
-
-	return {
-	    id:   `original-month-day:${ monthDay }`,
-	    text: `オリジナルの投稿日は ${ month } 月 ${ day } 日?`,
-	    kind: 'original_date' as const,
-	    condition: { type: 'original-month-day' as const, monthDay: String (monthDay) },
-	    source: 'default' as const,
-	    priorityWeight: 1,
-	    test: (post: Post) => originalMonthDayOf (post) === monthDay }
-      })
-
-  const titleQuestions = [
-      {
-	  id:   `title:length-at-least:${ titleLengthMedian }`,
-	  text: `タイトルは ${ titleLengthMedian } 文字以上?`,
-	  kind: 'title' as const,
-	  condition: {
-	      type: 'title-length-at-least' as const,
-	      length: titleLengthMedian },
-	  source: 'default' as const,
-	  priorityWeight: 1,
-	  test: (post: Post) => (post.title?.length ?? 0) >= titleLengthMedian },
-      {
-	  id:   'title:ascii',
-	  text: '題名に英数字が混じってゐる?',
-	  kind: 'title' as const,
-	  condition: { type: 'title-has-ascii' as const },
-	  source: 'default' as const,
-	  priorityWeight: 1,
-	  test: (post: Post) => /[A-Za-z0-9]/.test (post.title ?? '') }]
-      .filter (question => {
-	const yes = posts.filter (post => question.test (post)).length
-	const no = posts.length - yes
-	return yes >= 2 && no >= 2 && yes <= posts.length * .7 && no <= posts.length * .7
-      })
-
-  return [
-      ...sourceQuestions,
-      ...originalYearQuestions,
-      ...originalMonthQuestions,
-      ...originalMonthDayQuestions,
-      ...titleQuestions,
-      ...tagQuestions]
-}
-
-
-export const saveGekanatorGame = async ({
-    guessedPostId,
-    correctPostId,
-    answers,
-}: {
-    guessedPostId:  number
-    correctPostId:  number
-    answers:        GekanatorAnswerLog[]
-}): Promise<{ id: number }> =>
-    await apiPost ('/gekanator/games', {
-	guessed_post_id: guessedPostId,
-	correct_post_id: correctPostId,
-	answers: answers.map (answer => ({
-	    question_id: answer.questionId,
-	    question_text: answer.questionText,
-	    question_condition: answer.questionCondition ?? null,
-	    answer: answer.answer,
-	    original_answer: answer.originalAnswer })) })
-
-
-export const saveGekanatorQuestionSuggestion = async ({
-    gekanatorGameId,
-    questionText,
-    answer,
-}: {
-    gekanatorGameId:  number
-    questionText:     string
-    answer:           GekanatorAnswerValue
-}): Promise<{ id: number; count: number }> =>
-    await apiPost ('/gekanator/question_suggestions', {
-	gekanator_game_id: gekanatorGameId,
-	question_text: questionText,
-	answer })
-
-
-export const saveGekanatorExtraQuestionAnswers = async ({
-    gameId,
-    answers,
-}: {
-    gameId:   number
-    answers:  { questionId: number; answer: GekanatorAnswerValue }[]
-}) =>
-    await apiPost (`/gekanator/games/${ gameId }/extra_question_answers`, {
-	answers: answers.map (item => ({
-	    question_id: item.questionId,
-	    answer: item.answer })) })

frontend/src/lib/gekanatorCandidateRecovery.test.ts

@@ -1,151 +0,0 @@
-import { describe, expect, it } from 'vitest'
-
-import {
-    candidatePostsFor,
-    hardFilteredPostsForAnswer,
-    recoverCandidatePosts,
-} from '@/lib/gekanatorCandidateRecovery'
-
-import type {
-    GekanatorAnswerLog,
-    GekanatorAnswerValue,
-    GekanatorQuestion,
-} from '@/lib/gekanator'
-import type { Post } from '@/types'
-
-
-const post = (id: number): Post => ({
-  id,
-  versionNo: 1,
-  url: `https://example.com/posts/${ id }`,
-  title: `post ${ id }`,
-  thumbnail: null,
-  thumbnailBase: null,
-  tags: [],
-  viewed: false,
-  related: [],
-  originalCreatedFrom: null,
-  originalCreatedBefore: null,
-  createdAt: '2026-06-10T00:00:00.000Z',
-  updatedAt: '2026-06-10T00:00:00.000Z',
-  uploadedUser: null,
-})
-
-
-const postSimilarityQuestion = (
-    id:       string,
-    answers:  Record<`${ number }`, GekanatorAnswerValue>,
-): GekanatorQuestion => ({
-  id,
-  text: `${ id }?`,
-  kind: 'post_similarity',
-  condition: {
-      type: 'post-similarity',
-      postId: 9999,
-      answer: 'yes',
-      threshold: 0.65 },
-  source: 'user_suggested',
-  priorityWeight: 1,
-  exampleAnswers: answers,
-  test: candidate => answers[String (candidate.id) as `${ number }`] === 'yes',
-})
-
-
-const answer = (
-    question:  GekanatorQuestion,
-    value:     GekanatorAnswerValue,
-): GekanatorAnswerLog => ({
-  questionId: question.id,
-  questionText: question.text,
-  questionCondition: question.condition,
-  answer: value,
-  originalAnswer: value,
-})
-
-
-describe('candidatePostsFor', () => {
-  it('lets recovered candidates ignore old answers but not later answers', () => {
-    const posts = [post (1), post (2), post (3)]
-    const oldQuestion = postSimilarityQuestion ('old', {
-	1: 'no',
-	2: 'yes',
-	3: 'yes',
-    })
-    const laterQuestion = postSimilarityQuestion ('later', {
-	1: 'no',
-	2: 'no',
-	3: 'yes',
-    })
-
-    const candidates = candidatePostsFor ({
-	posts,
-	questions: [oldQuestion, laterQuestion],
-	answers: [answer (oldQuestion, 'yes'), answer (laterQuestion, 'yes')],
-	softenedQuestionIds: new Set (),
-	rejectedPostIds: new Set (),
-	recoveredCandidatePosts: new Map ([
-	    [1, 1],
-	    [3, 1],
-	]) })
-
-    expect(candidates.map (candidate => candidate.id)).toEqual ([3])
-  })
-
-  it('does not let recovered candidates bypass explicit rejected posts', () => {
-    const posts = [post (1), post (2)]
-    const question = postSimilarityQuestion ('question', {
-	1: 'yes',
-	2: 'yes',
-    })
-
-    const candidates = candidatePostsFor ({
-	posts,
-	questions: [question],
-	answers: [answer (question, 'yes')],
-	softenedQuestionIds: new Set (),
-	rejectedPostIds: new Set ([1]),
-	recoveredCandidatePosts: new Map ([[1, 1]]) })
-
-    expect(candidates.map (candidate => candidate.id)).toEqual ([2])
-  })
-})
-
-
-describe('hardFilteredPostsForAnswer', () => {
-  it('returns zero candidates without falling back to the original pool', () => {
-    const posts = [post (1), post (2)]
-    const question = postSimilarityQuestion ('question', {
-	1: 'yes',
-	2: 'yes',
-    })
-
-    expect(hardFilteredPostsForAnswer ({
-	posts,
-	question,
-	answer: 'no',
-    })).toEqual ([])
-  })
-})
-
-
-describe('recoverCandidatePosts', () => {
-  it('recovers high-score non-rejected, non-eligible candidates in staged batches', () => {
-    const posts = Array.from ({ length: 10 }, (_value, index) => post (index + 1))
-    const scores = new Map (posts.map (candidate => [candidate.id, candidate.id]))
-
-    const recovered = recoverCandidatePosts ({
-	posts,
-	scores,
-	rejectedPostIds: new Set ([10]),
-	recoveredCandidatePosts: new Map ([[8, 1]]),
-	eligiblePostIds: new Set ([9]),
-	answerCountAtRecovery: 2,
-	recoveryStepCount: 0,
-    })
-
-    expect(recovered?.recoveryStepCount).toBe (1)
-    expect([...(recovered?.recoveredCandidatePosts.keys () ?? [])])
-      .toEqual ([8, 7, 6, 5, 4, 3, 2])
-    expect(recovered?.recoveredCandidatePosts.get (7)).toBe (2)
-  })
-})

frontend/src/lib/gekanatorCandidateRecovery.ts

@@ -1,146 +0,0 @@
-import { expectedAnswerForQuestion } from '@/lib/gekanator'
-
-import type {
-    GekanatorAnswerLog,
-    GekanatorAnswerValue,
-    GekanatorQuestion,
-} from '@/lib/gekanator'
-import type { Post } from '@/types'
-
-
-export type RecoveredCandidatePost = {
-    postId:                number
-    answerCountAtRecovery: number }
-
-
-export const candidatePostsFor = ({
-    posts,
-    questions,
-    answers,
-    softenedQuestionIds,
-    rejectedPostIds,
-    recoveredCandidatePosts,
-}: {
-    posts:                   Post[]
-    questions:               GekanatorQuestion[]
-    answers:                 GekanatorAnswerLog[]
-    softenedQuestionIds:     Set<string>
-    rejectedPostIds:         Set<number>
-    recoveredCandidatePosts: Map<number, number>
-}): Post[] => {
-  const questionById = new Map (questions.map (question => [question.id, question]))
-
-  return posts.filter (post => {
-    if (rejectedPostIds.has (post.id))
-      return false
-
-    const answerCountAtRecovery = recoveredCandidatePosts.get (post.id)
-
-    return answers.every ((answer, index) => {
-      if (answerCountAtRecovery !== undefined && index < answerCountAtRecovery)
-	return true
-
-      if (softenedQuestionIds.has (answer.questionId))
-	return true
-
-      const question = questionById.get (answer.questionId)
-      if (!(question))
-	return true
-
-      switch (answer.answer)
-      {
-      case 'yes':
-      case 'no': {
-	const expected = expectedAnswerForQuestion (question, post)
-	return expected === null || expected === 'unknown' || expected === answer.answer
-      }
-      default:
-	return true
-      }
-    })
-  })
-}
-
-
-export const hardFilteredPostsForAnswer = ({
-    posts,
-    question,
-    answer,
-}: {
-    posts:     Post[]
-    question:  GekanatorQuestion
-    answer:    GekanatorAnswerValue
-}): Post[] => {
-  if (answer === 'unknown')
-    return posts
-
-  return posts.filter (post => {
-    const expected = expectedAnswerForQuestion (question, post)
-    return expected === null || expected === 'unknown' || expected === answer
-  })
-}
-
-
-const concreteAnswerOptions: GekanatorAnswerValue[] = [
-    'yes',
-    'no',
-    'partial',
-    'probably_no']
-
-
-export const allConcreteAnswerOptionsExhausted = (
-    posts:      Post[],
-    question:   GekanatorQuestion | null,
-): boolean => {
-  if (!(question))
-    return false
-
-  return concreteAnswerOptions.every (answer =>
-      hardFilteredPostsForAnswer ({ posts, question, answer }).length === 0)
-}
-
-
-const nextRecoveryBatchSize = (recoveryStepCount: number): number =>
-    6 * (2 ** recoveryStepCount)
-
-
-export const recoverCandidatePosts = ({
-    posts,
-    scores,
-    rejectedPostIds,
-    recoveredCandidatePosts,
-    eligiblePostIds,
-    answerCountAtRecovery,
-    recoveryStepCount,
-}: {
-    posts:                   Post[]
-    scores:                  Map<number, number>
-    rejectedPostIds:         Set<number>
-    recoveredCandidatePosts: Map<number, number>
-    eligiblePostIds:         Set<number>
-    answerCountAtRecovery:   number
-    recoveryStepCount:       number
-}): {
-    recoveredCandidatePosts: Map<number, number>
-    recoveryStepCount:       number
-} | null => {
-  const recovered = new Map (recoveredCandidatePosts)
-  const candidates = posts
-      .filter (post =>
-	  !(rejectedPostIds.has (post.id))
-	  && !(eligiblePostIds.has (post.id))
-	  && !(recovered.has (post.id)))
-      .sort ((a, b) =>
-	  (scores.get (b.id) ?? Number.NEGATIVE_INFINITY)
-	      - (scores.get (a.id) ?? Number.NEGATIVE_INFINITY))
-      .slice (0, nextRecoveryBatchSize (recoveryStepCount))
-
-  if (candidates.length === 0)
-    return null
-
-  candidates.forEach (post => recovered.set (post.id, answerCountAtRecovery))
-
-  return {
-      recoveredCandidatePosts: recovered,
-      recoveryStepCount: recoveryStepCount + 1 }
-}

frontend/src/lib/gekanatorQuestionFilters.ts

@@ -1,167 +0,0 @@
-import { titleLengthMinimumForCondition } from '@/lib/gekanator'
-
-import type {
-    GekanatorAnswerLog,
-    GekanatorAnswerValue,
-    GekanatorQuestion,
-} from '@/lib/gekanator'
-
-
-export const monthForCondition = (
-    condition:  GekanatorQuestion['condition'],
-): number | null => {
-  if (condition.type === 'original-month')
-    return condition.month
-
-  if (condition.type !== 'original-month-day')
-    return null
-
-  const month = Number (condition.monthDay.split ('-')[0])
-  return Number.isInteger (month) ? month : null
-}
-
-
-const isTitleLengthContradiction = (
-    candidate:  GekanatorQuestion['condition'],
-    previous:   GekanatorQuestion['condition'],
-    answer:     GekanatorAnswerValue,
-): boolean => {
-  const candidateLength = titleLengthMinimumForCondition (candidate)
-  const previousLength = titleLengthMinimumForCondition (previous)
-  if (candidateLength === null || previousLength === null)
-    return false
-
-  switch (answer)
-  {
-  case 'yes':
-    return candidateLength <= previousLength
-  case 'no':
-    return candidateLength >= previousLength
-  default:
-    return false
-  }
-}
-
-
-const isQuestionRedundantAfterAnswers = (
-    question:  GekanatorQuestion,
-    answers:   GekanatorAnswerLog[],
-): boolean => answers.some (answer => {
-  const previous = answer.questionCondition
-  return previous !== undefined
-      && isTitleLengthContradiction (question.condition, previous, answer.answer)
-})
-
-
-const isSourceFactBlocked = (
-    candidate:  GekanatorQuestion['condition'],
-    previous:   GekanatorQuestion['condition'],
-    answer:     GekanatorAnswerValue,
-): boolean => {
-  if (candidate.type !== 'source' || previous.type !== 'source')
-    return false
-
-  switch (answer)
-  {
-  case 'yes':
-    return true
-  case 'no':
-    return candidate.host === previous.host
-  default:
-    return false
-  }
-}
-
-
-const isOriginalYearFactBlocked = (
-    candidate:  GekanatorQuestion['condition'],
-    previous:   GekanatorQuestion['condition'],
-    answer:     GekanatorAnswerValue,
-): boolean => {
-  if (candidate.type !== 'original-year' || previous.type !== 'original-year')
-    return false
-
-  switch (answer)
-  {
-  case 'yes':
-    return true
-  case 'no':
-    return candidate.year === previous.year
-  default:
-    return false
-  }
-}
-
-
-const isOriginalMonthFactBlocked = (
-    candidate:  GekanatorQuestion['condition'],
-    previous:   GekanatorQuestion['condition'],
-    answer:     GekanatorAnswerValue,
-): boolean => {
-  switch (answer)
-  {
-  case 'yes':
-    if (previous.type === 'original-month')
-      {
-	if (candidate.type === 'original-month')
-	  return true
-
-	if (candidate.type === 'original-month-day')
-	  return monthForCondition (candidate) !== previous.month
-
-	return false
-      }
-
-    if (previous.type === 'original-month-day')
-      return candidate.type === 'original-month'
-	  || candidate.type === 'original-month-day'
-
-    return false
-  case 'no':
-    if (previous.type === 'original-month')
-      {
-	if (candidate.type === 'original-month')
-	  return candidate.month === previous.month
-
-	if (candidate.type === 'original-month-day')
-	  return monthForCondition (candidate) === previous.month
-
-	return false
-      }
-
-    if (previous.type === 'original-month-day')
-      return candidate.type === 'original-month-day'
-	  && candidate.monthDay === previous.monthDay
-
-    return false
-  default:
-    return false
-  }
-}
-
-
-const isFactQuestionBlocked = (
-    candidate:  GekanatorQuestion['condition'],
-    previous:   GekanatorQuestion['condition'],
-    answer:     GekanatorAnswerValue,
-): boolean => {
-  if (!(answer === 'yes' || answer === 'no'))
-    return false
-
-  return isSourceFactBlocked (candidate, previous, answer)
-      || isOriginalYearFactBlocked (candidate, previous, answer)
-      || isOriginalMonthFactBlocked (candidate, previous, answer)
-}
-
-
-export const isQuestionHardFilteredAfterAnswers = (
-    question:  GekanatorQuestion,
-    answers:   GekanatorAnswerLog[],
-): boolean => answers.some (answer => {
-  const previous = answer.questionCondition
-  if (previous === undefined)
-    return false
-
-  return isQuestionRedundantAfterAnswers (question, [answer])
-      || isFactQuestionBlocked (question.condition, previous, answer.answer)
-})

frontend/src/lib/queryKeys.ts

@@ -8,13 +8,6 @@ export const postsKeys = {
     changes:  (p: { post?: string; tag?: string; page: number; limit: number }) =>
 		  ['posts', 'changes', p] as const }
 
-export const gekanatorKeys = {
-    root:      ['gekanator'] as const,
-    posts:     () => ['gekanator', 'posts'] as const,
-    questions: () => ['gekanator', 'questions'] as const,
-    extraQuestions: (gameId: number, nonce: string) =>
-		       ['gekanator', 'games', gameId, 'extra-questions', nonce] as const }
-
 export const tagsKeys = {
     root:         ['tags'] as const,
     index:        (p: FetchTagsParams) => ['tags', 'index', p] as const,

frontend/src/pages/GekanatorPage.test.tsx

@@ -1,154 +0,0 @@
-import { describe, expect, it } from 'vitest'
-
-import { isQuestionHardFilteredAfterAnswers } from '@/lib/gekanatorQuestionFilters'
-
-import type {
-    GekanatorAnswerLog,
-    GekanatorAnswerValue,
-    GekanatorQuestion,
-    GekanatorQuestionCondition,
-} from '@/lib/gekanator'
-
-
-const question = (
-    condition:  GekanatorQuestionCondition,
-): GekanatorQuestion => ({
-  id: `${ condition.type }:candidate`,
-  text: 'candidate?',
-  kind: condition.type === 'source'
-      ? 'source'
-      : condition.type.startsWith ('original-')
-	? 'original_date'
-	: condition.type.startsWith ('title-')
-	  ? 'title'
-	  : 'tag',
-  condition,
-  source: 'default',
-  priorityWeight: 1,
-  test: () => false,
-})
-
-
-const answer = (
-    condition:  GekanatorQuestionCondition,
-    value:      GekanatorAnswerValue,
-): GekanatorAnswerLog => ({
-  questionId: 'previous',
-  questionText: 'previous?',
-  questionCondition: condition,
-  answer: value,
-  originalAnswer: value,
-})
-
-
-const blocked = (
-    candidate:  GekanatorQuestionCondition,
-    previous:   GekanatorQuestionCondition,
-    value:      GekanatorAnswerValue,
-): boolean =>
-    isQuestionHardFilteredAfterAnswers (question (candidate), [answer (previous, value)])
-
-
-describe('isQuestionHardFilteredAfterAnswers', () => {
-  it('blocks only contradictory or redundant month questions after a yes answer', () => {
-    const previous: GekanatorQuestionCondition = { type: 'original-month', month: 12 }
-
-    expect(blocked ({ type: 'original-month', month: 12 }, previous, 'yes')).toBe(true)
-    expect(blocked ({ type: 'original-month', month: 2 }, previous, 'yes')).toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '2-14' }, previous, 'yes'))
-      .toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-25' }, previous, 'yes'))
-      .toBe(false)
-    expect(blocked ({ type: 'original-year', year: 2024 }, previous, 'yes')).toBe(false)
-    expect(blocked ({ type: 'source', host: 'example.com' }, previous, 'yes')).toBe(false)
-    expect(blocked ({ type: 'tag', key: 'character:喜多郁代' }, previous, 'yes')).toBe(false)
-  })
-
-  it('blocks same-month facts after a no answer', () => {
-    const previous: GekanatorQuestionCondition = { type: 'original-month', month: 12 }
-
-    expect(blocked ({ type: 'original-month', month: 12 }, previous, 'no')).toBe(true)
-    expect(blocked ({ type: 'original-month', month: 2 }, previous, 'no')).toBe(false)
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-25' }, previous, 'no'))
-      .toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '2-14' }, previous, 'no'))
-      .toBe(false)
-  })
-
-  it('blocks all month and month-day questions after a month-day yes answer', () => {
-    const previous: GekanatorQuestionCondition = {
-      type: 'original-month-day',
-      monthDay: '12-25',
-    }
-
-    expect(blocked ({ type: 'original-month', month: 12 }, previous, 'yes')).toBe(true)
-    expect(blocked ({ type: 'original-month', month: 2 }, previous, 'yes')).toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-25' }, previous, 'yes'))
-      .toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-26' }, previous, 'yes'))
-      .toBe(true)
-  })
-
-  it('blocks the same month-day only after a month-day no answer', () => {
-    const previous: GekanatorQuestionCondition = {
-      type: 'original-month-day',
-      monthDay: '12-25',
-    }
-
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-25' }, previous, 'no'))
-      .toBe(true)
-    expect(blocked ({ type: 'original-month-day', monthDay: '12-26' }, previous, 'no'))
-      .toBe(false)
-    expect(blocked ({ type: 'original-month', month: 12 }, previous, 'no')).toBe(false)
-  })
-
-  it('blocks year and source as single-value facts', () => {
-    expect(blocked (
-      { type: 'original-year', year: 2025 },
-      { type: 'original-year', year: 2024 },
-      'yes',
-    )).toBe(true)
-    expect(blocked (
-      { type: 'original-year', year: 2024 },
-      { type: 'original-year', year: 2024 },
-      'no',
-    )).toBe(true)
-    expect(blocked (
-      { type: 'source', host: 'b.example' },
-      { type: 'source', host: 'a.example' },
-      'yes',
-    )).toBe(true)
-    expect(blocked (
-      { type: 'source', host: 'b.example' },
-      { type: 'source', host: 'a.example' },
-      'no',
-    )).toBe(false)
-  })
-
-  it('does not hard-filter partial, probably_no, or unknown fact answers', () => {
-    const previous: GekanatorQuestionCondition = { type: 'original-month', month: 12 }
-    const candidate: GekanatorQuestionCondition = { type: 'original-month', month: 2 }
-
-    expect(blocked (candidate, previous, 'partial')).toBe(false)
-    expect(blocked (candidate, previous, 'probably_no')).toBe(false)
-    expect(blocked (candidate, previous, 'unknown')).toBe(false)
-  })
-
-  it('keeps title-length hard redundancy for yes and no only', () => {
-    const previous: GekanatorQuestionCondition = {
-      type: 'title-length-at-least',
-      length: 30,
-    }
-
-    expect(blocked ({ type: 'title-length-at-least', length: 20 }, previous, 'yes'))
-      .toBe(true)
-    expect(blocked ({ type: 'title-length-at-least', length: 40 }, previous, 'yes'))
-      .toBe(false)
-    expect(blocked ({ type: 'title-length-at-least', length: 40 }, previous, 'no'))
-      .toBe(true)
-    expect(blocked ({ type: 'title-length-at-least', length: 20 }, previous, 'no'))
-      .toBe(false)
-    expect(blocked ({ type: 'title-length-at-least', length: 20 }, previous, 'partial'))
-      .toBe(false)
-  })
-})

frontend/src/pages/theatres/TheatreDetailPage.test.tsx

@@ -1,4 +1,4 @@
-import { act, fireEvent, screen, waitFor } from '@testing-library/react'
+import { fireEvent, screen, waitFor } from '@testing-library/react'
 import { Route, Routes } from 'react-router-dom'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
@@ -31,31 +31,15 @@ const dialogue = vi.hoisted (() => ({
   confirm: vi.fn (),
 }))
 
-const postEmbed = vi.hoisted (() => ({
-  props: vi.fn (),
-  play:  vi.fn (),
-  seek:  vi.fn (),
-}))
-
 vi.mock ('@/lib/api', () => api)
 vi.mock ('@/lib/posts', () => postsApi)
 vi.mock ('@/components/dialogues/DialogueProvider', () => ({
   useDialogue: () => dialogue,
 }))
 vi.mock ('@/components/PostEmbed', () => ({
-  default: (props: {
+  default: ({ post }: {
-    ref?: { current: unknown }
     post: { title: string | null; url: string }
-  }) => {
+  }) => <div>Embed:{post.title || post.url}</div>,
-    postEmbed.props (props)
-    if (props.ref)
-      props.ref.current = {
-        play: postEmbed.play,
-        seek: postEmbed.seek,
-      }
-
-    return <div>Embed:{props.post.title || props.post.url}</div>
-  },
 }))
 vi.mock ('@/components/PostEditForm', () => ({
   default: () => <div>Post edit form</div>,
@@ -169,7 +153,6 @@ const mockDefaultApi = () => {
 
 describe ('TheatreDetailPage', () => {
   beforeEach (() => {
-    vi.useRealTimers ()
     vi.clearAllMocks ()
     mockDefaultApi ()
   })
@@ -205,83 +188,6 @@ describe ('TheatreDetailPage', () => {
       .toBeInTheDocument ()
   })
 
-  it ('does not seek to zero while applying video length from the player', async () => {
-    api.apiPut.mockImplementation ((path: string) => {
-      switch (path)
-      {
-      case '/theatres/7/watching':
-        return Promise.resolve (buildTheatreInfo ({
-          hostFlg:       true,
-          postId:        currentPost.id,
-          postStartedAt: '2026-01-02T03:04:05.000Z',
-          postElapsedMs: 7_000,
-          watchingUsers: [{ id: 1, name: 'tester' }],
-          skipVote:      {
-            votesCount:         0,
-            requiredCount:      2,
-            watchingUsersCount: 1,
-            voted:              false,
-          },
-        }))
-
-      default:
-        return Promise.reject (new Error (`Unexpected PUT ${ path }`))
-      }
-    })
-
-    renderPage ()
-    await screen.findByText ('Embed:上映中の投稿')
-
-    const props = postEmbed.props.mock.calls.at (-1)![0]
-
-    act (() => {
-      props.onVideoReady (120_000)
-      props.onPlaybackChange (0)
-    })
-
-    const seekMs = postEmbed.seek.mock.calls[0][0]
-    expect (seekMs).toBeGreaterThanOrEqual (7_000)
-    expect (seekMs).toBeLessThan (10_000)
-    expect (postEmbed.seek).not.toHaveBeenCalledWith (0)
-  })
-
-  it ('does not advance host post while video length is unknown', async () => {
-    api.apiPut.mockImplementation ((path: string) => {
-      switch (path)
-      {
-      case '/theatres/7/watching':
-        return Promise.resolve (buildTheatreInfo ({
-          hostFlg:       true,
-          postId:        currentPost.id,
-          postStartedAt: '2026-01-02T03:04:05.000Z',
-          postElapsedMs: 4_000,
-          watchingUsers: [{ id: 1, name: 'tester' }],
-          skipVote:      {
-            votesCount:         0,
-            requiredCount:      2,
-            watchingUsersCount: 1,
-            voted:              false,
-          },
-        }))
-
-      default:
-        return Promise.reject (new Error (`Unexpected PUT ${ path }`))
-      }
-    })
-
-    renderPage ()
-
-    await screen.findByText ('Embed:上映中の投稿')
-    await waitFor (() => {
-      expect (api.apiPut).toHaveBeenCalledWith ('/theatres/7/watching')
-    })
-
-    await waitFor (() => {
-      expect (api.apiPut).toHaveBeenCalledTimes (2)
-    }, { timeout: 2_500 })
-    expect (api.apiPatch).not.toHaveBeenCalledWith ('/theatres/7/next_post')
-  })
-
   it ('deletes an owned comment after confirmation', async () => {
     renderPage ()
 

frontend/src/pages/theatres/TheatreDetailPage.tsx

@@ -443,13 +443,9 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
     if (!(theatreInfo.postStartedAt))
       return
 
-    const currentVideoLength = videoLengthRef.current
-    if (currentVideoLength <= 0)
-      return
-
     const targetTime = Math.min (
 	currentPostElapsedMs (theatreInfo),
-	currentVideoLength)
+	videoLength)
 
     const drift = Math.abs (currentTimeMs - targetTime)
 
@@ -481,7 +477,6 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 	: 0
 
     setVideoLength (playableDurationMs)
-    videoLengthRef.current = playableDurationMs
 
     if (playableDurationMs <= 0)
       {