#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

@@ -1,23 +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
-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

@@ -1,46 +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.save
-      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

@@ -1,57 +0,0 @@
-class GekanatorQuestionsController < ApplicationController
-  def index
-    return head :not_found unless current_user&.admin?
-
-    questions = GekanatorQuestion.accepted.order(priority_weight: :desc, id: :asc)
-
-    render json: {
-      questions: questions.map { |question| question_json(question) }
-    }
-  end
-
-  private
-
-  def question_json question
-    {
-      id: question_id_for(question),
-      text: question.text,
-      kind: question.kind,
-      condition: condition_json(question.condition),
-      source: question.source,
-      priority_weight: question.priority_weight
-    }
-  end
-
-  def question_id_for question
-    condition = condition_json(question.condition).deep_symbolize_keys
-
-    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-greater-than'
-      "title:length-greater-than:#{ condition[:length] }"
-    when 'title-has-ascii'
-      'title:ascii'
-    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
-
-    json
-  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

@@ -1,12 +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
-
-  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

@@ -1,22 +0,0 @@
-class GekanatorQuestion < ApplicationRecord
-  KINDS = ['tag', 'source', 'title', 'original_date'].freeze
-  SOURCES = ['user_suggested', 'ai_generated', 'admin_curated'].freeze
-  STATUSES = ['pending', 'accepted', 'rejected'].freeze
-
-  belongs_to :gekanator_question_suggestion, optional: true
-  belongs_to :created_by, class_name: 'User', optional: true
-
-  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_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

@@ -11,16 +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 :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/config/routes.rb

@@ -63,19 +63,6 @@ Rails.application.routes.draw do
     end
   end
 
-  namespace :gekanator do
-    resources :games, only: [:create], controller: '/gekanator_games'
-    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/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_09_001000) 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
@@ -48,60 +48,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) 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_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"
@@ -191,19 +137,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) do
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
-  create_table "post_tag_sections", primary_key: ["post_id", "tag_id", "begin_ms"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "post_id", null: false
-    t.bigint "tag_id", null: false
-    t.integer "begin_ms", null: false
-    t.integer "end_ms", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["post_id", "begin_ms"], name: "idx_post_tag_sections_post_id_begin_ms"
-    t.index ["tag_id"], name: "fk_rails_8be3847903"
-    t.check_constraint "`begin_ms` < `end_ms`", name: "chk_post_tag_sections_end_ms_after_begin_ms"
-    t.check_constraint "`begin_ms` >= 0", name: "chk_post_tag_sections_begin_ms_natural"
-  end
-
   create_table "post_tags", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "tag_id", null: false
@@ -254,11 +187,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) do
     t.datetime "original_created_before"
     t.datetime "updated_at", null: false
     t.integer "version_no", null: false
-    t.integer "video_ms"
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
-    t.index ["video_ms", "id"], name: "idx_posts_video_ms_id"
-    t.check_constraint "(`video_ms` is null) or (`video_ms` > 0)", name: "chk_posts_video_ms_positive"
     t.check_constraint "`version_no` > 0", name: "chk_posts_version_no_positive"
   end
 
@@ -409,7 +339,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["expires_at"], name: "index_theatre_watching_users_on_expires_at"
-    t.index ["theatre_id", "expires_at"], name: "idx_on_theatre_id_skip_expires_at_4c8de1dd42"
     t.index ["theatre_id", "expires_at"], name: "index_theatre_watching_users_on_theatre_id_and_expires_at"
     t.index ["theatre_id"], name: "index_theatre_watching_users_on_theatre_id"
     t.index ["user_id"], name: "index_theatre_watching_users_on_user_id"
@@ -549,14 +478,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) 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_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"
@@ -574,8 +495,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_09_001000) do
   add_foreign_key "post_implications", "posts", column: "parent_post_id"
   add_foreign_key "post_similarities", "posts"
   add_foreign_key "post_similarities", "posts", column: "target_post_id"
-  add_foreign_key "post_tag_sections", "posts"
-  add_foreign_key "post_tag_sections", "tags"
   add_foreign_key "post_tags", "posts"
   add_foreign_key "post_tags", "tags"
   add_foreign_key "post_tags", "users", column: "created_user_id"

backend/spec/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

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.ts

@@ -1,395 +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'
-
-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-greater-than'; length: number }
-    | { type: 'title-has-ascii' }
-
-export type StoredGekanatorQuestion = {
-    id:              string
-    text:            string
-    kind:            GekanatorQuestionKind
-    condition:       GekanatorQuestionCondition
-    source?:         GekanatorQuestionSource
-    priorityWeight?: number }
-
-export type GekanatorQuestion = {
-    id:              string
-    text:            string
-    kind:            GekanatorQuestionKind
-    condition:       GekanatorQuestionCondition
-    source:          GekanatorQuestionSource
-    priorityWeight:  number
-    test:            (post: Post) => boolean }
-
-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,
-    condition:  GekanatorQuestionCondition,
-): boolean => {
-  switch (condition.type)
-  {
-  case 'tag':
-    return questionableTag (post, condition.key)
-  case 'source':
-    return hostOf (post) === condition.host
-  case 'original-year':
-    return originalYearOf (post) === condition.year
-  case 'original-month':
-    return originalMonthOf (post) === condition.month
-  case 'original-month-day':
-    return originalMonthDayOf (post) === condition.monthDay
-  case 'title-length-greater-than':
-    return (post.title?.length ?? 0) > condition.length
-  case 'title-has-ascii':
-    return /[A-Za-z0-9]/.test (post.title ?? '')
-  }
-}
-
-
-export const restoreGekanatorQuestion = (
-    question:  StoredGekanatorQuestion,
-): GekanatorQuestion => ({
-  ...question,
-  source: question.source ?? 'default',
-  priorityWeight: question.priorityWeight ?? 1,
-  test: (post: Post) => questionMatches (post, question.condition) })
-
-
-export const storeGekanatorQuestion = (
-    question:  GekanatorQuestion,
-): StoredGekanatorQuestion => ({
-  id: question.id,
-  text: question.text,
-  kind: question.kind,
-  condition: question.condition,
-  source: question.source,
-  priorityWeight: question.priorityWeight })
-
-
-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 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:long',
-	  text: '題名が長めの投稿?',
-	  kind: 'title' as const,
-	  condition: {
-	      type: 'title-length-greater-than' 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 })

frontend/src/lib/queryKeys.ts

@@ -8,11 +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 }
-
 export const tagsKeys = {
     root:         ['tags'] as const,
     index:        (p: FetchTagsParams) => ['tags', 'index', p] as const,

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)
       {