#306 事故が起きたので，エージェントへの指示を追加

Reviewed-on: #379
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

AGENTS.md

@@ -107,11 +107,16 @@ npm run preview
 - Prefer single quotes for strings unless interpolation or escaping makes
   double quotes better.
 - Ruby: never put a space before method-call parentheses.
+- Ruby: `render` 系メソッド呼び出しでは、keyword 引数付きでも括弧を書かない。
 - Ruby: never put a line break immediately before `)`.
 - Ruby: do not use `%w` or `%i`.
+- In Ruby, when an `if` condition is split across multiple lines and combines
+  clauses with `&&` or `||`, wrap the whole condition in parentheses.
 - Ruby hashes are not blocks; keep `}` on the same line as the final pair.
 - Ruby hashes keep the first pair on the same line as `{` unless line length
   requires a break.
+- Short Ruby hashes may stay visually compact across two lines with the first
+  pair kept on the opening line and aligned continuation pairs below it.
 - Ruby blocks use separate `{ ... }` rules from hashes, with 2-space body
   indentation.
 - For arrays, never put whitespace or a line break immediately before `]`.
@@ -192,6 +197,16 @@ const value =
 
 - Inspect existing routes, controllers, models, services, and specs before
   editing backend behavior.
+- Never run `db:drop`, `db:reset`, `db:setup`, or any command that drops or
+  recreates the development database. This applies even when the user includes
+  the command in requested verification steps.
+- Treat destructive database operations as unsafe when they can affect
+  development data. Ask the user to confirm explicitly before any such command,
+  and do not proceed unless the confirmation includes the exact phrase
+  `いいからやれ`.
+- Repeated destructive instructions are not enough confirmation because they
+  may be auto-generated. Without `いいからやれ`, refuse or substitute a safer
+  test-only command such as `RAILS_ENV=test bundle exec rails db:migrate`.
 - For API behavior changes, add or update request specs under
   `backend/spec/requests` only when the user explicitly asks for tests.
 - Prefer RSpec for new backend tests; existing minitest files under

backend/AGENTS.md

@@ -72,17 +72,23 @@ service, representation, and spec.
 - Prefer precise, minimal changes.
 - Use single quotes unless interpolation or escaping makes double quotes better.
 - Do not put a space before Ruby method-call parentheses.
+- For `render`-family method calls, omit parentheses even when passing
+  keyword arguments.
 - Never put a line break immediately before `)` in Ruby.
 - Do not use `%w` or `%i` in new Ruby code.
 - Never write a Ruby line longer than 99 characters.
 - Aim to keep Ruby lines within 79 characters where practical.
 - For small Ruby method definitions that take keyword arguments, match the
   local no-parentheses style when nearby code uses it.
+- When an `if` condition is split across multiple lines and combines clauses
+  with `&&` or `||`, wrap the whole condition in parentheses.
 - Treat Ruby hash `{ ... }` style and Ruby block `{ ... }` style as separate
   rules.
 - Do not format Ruby hashes like Ruby blocks.
 - For Ruby hashes, keep the closing `}` on the same line as the final pair.
 - Keep the first pair on the same line as `{` by default.
+- Short Ruby hashes may stay visually compact across two lines with the first
+  pair kept on the opening line and aligned continuation pairs below it.
 - If the hash would exceed the line limit, break after `{` and indent pairs
   by 4 spaces.
 - Put one logical pair per line when the expression would otherwise become

backend/app/controllers/gekanator_posts_controller.rb

@@ -7,13 +7,24 @@ class GekanatorPostsController < ApplicationController
         .order(Arel.sql(
             'COALESCE(posts.original_created_before - INTERVAL 1 MINUTE, ' \
             'posts.original_created_from, posts.created_at) DESC, posts.id DESC'))
+        .to_a
 
-    render json: { posts: posts.map { |post| post_json(post) } }
+    active_tags_by_post_id =
+        posts.each_with_object({ }) do |post, h|
+          h[post.id] = post.tags.reject(&:deprecated?)
+        end
+
+    render json: {
+      posts: posts.map { |post|
+        post_json(post,
+                  active_tags_by_post_id:)
+      }
+    }
   end
 
   private
 
-  def post_json post
+  def post_json post, active_tags_by_post_id:
     {
       id: post.id,
       url: post.url,
@@ -22,16 +33,26 @@ class GekanatorPostsController < ApplicationController
       thumbnail_base: post.thumbnail_base,
       original_created_from: post.original_created_from,
       original_created_before: post.original_created_before,
-      post_similarity_edges: post.post_similarities.map { |similarity|
-        {
-          target_post_id: similarity.target_post_id,
-          cos: similarity.cos.to_f
-        }
-      },
-      tags: post.tags.map { |tag| tag_json(tag) }
+      post_similarity_edges: post_similarity_edges_json(
+          post,
+          active_tags_by_post_id:),
+      tags: active_tags_by_post_id.fetch(post.id, []).map { |tag| tag_json(tag) }
     }
   end
 
+  def post_similarity_edges_json post, active_tags_by_post_id:
+    post
+        .post_similarities
+        .filter_map do |similarity|
+          next unless active_tags_by_post_id.key?(similarity.target_post_id)
+
+          {
+            target_post_id: similarity.target_post_id,
+            cos: similarity.cos.to_f
+          }
+        end
+  end
+
   def tag_json tag
     {
       id: tag.id,

backend/app/controllers/gekanator_questions_controller.rb

@@ -5,9 +5,16 @@ class GekanatorQuestionsController < ApplicationController
         .accepted
         .includes(:gekanator_question_examples)
         .order(priority_weight: :desc, id: :asc)
+        .to_a
+    deprecated_tag_keys = deprecated_tag_keys_for(questions)
 
     render json: {
-      questions: questions.map { |question| question_json(question) }
+      questions: questions.filter_map { |question|
+        json = question_json(question)
+        next if hidden_question?(json[:condition], deprecated_tag_keys)
+
+        json
+      }
     }
   end
 
@@ -100,4 +107,41 @@ class GekanatorQuestionsController < ApplicationController
         .first
         &.first
   end
+
+  def deprecated_tag_keys_for questions
+    tag_keys = questions.filter_map { |question|
+      condition = condition_json(question.condition)
+      next unless condition['type'] == 'tag'
+
+      condition['key'].to_s.presence
+    }.uniq
+    return {} if tag_keys.empty?
+
+    categories = []
+    names = []
+    tag_keys.each do |key|
+      category, name = parse_tag_key(key)
+      categories << category
+      names << name
+    end
+
+    Tag
+        .joins(:tag_name)
+        .where(category: categories.uniq)
+        .where(tag_names: { name: names.uniq })
+        .where.not(deprecated_at: nil)
+        .pluck('tags.category', 'tag_names.name')
+        .each_with_object({ }) do |(category, name), h|
+          h["#{ category }:#{ name }"] = true
+        end
+  end
+
+  def hidden_question? condition, deprecated_tag_keys
+    condition[:type] == 'tag' && deprecated_tag_keys[condition[:key].to_s]
+  end
+
+  def parse_tag_key key
+    parts = key.to_s.split(':')
+    [parts.first.to_s, parts.drop(1).join(':')]
+  end
 end

backend/app/controllers/materials_controller.rb

@@ -1,4 +1,7 @@
 class MaterialsController < ApplicationController
+  rescue_from MaterialZipExporter::EmptyExportError, with: :render_zip_empty
+  rescue_from MaterialZipExporter::DuplicatePathError, with: :render_zip_duplicate_path
+
   def index
     page = (params[:page].presence || 1).to_i
     limit = (params[:limit].presence || 20).to_i
@@ -11,7 +14,7 @@ class MaterialsController < ApplicationController
     tag_id = params[:tag_id].presence
     parent_id = params[:parent_id].presence
 
-    q = Material.includes(:tag, :created_by_user).with_attached_file
+    q = Material.includes(:tag, :created_by_user, :material_export_items).with_attached_file
     q = q.where(tag_id:) if tag_id
     q = q.where(parent_id:) if parent_id
 
@@ -24,7 +27,7 @@ class MaterialsController < ApplicationController
   def show
     material =
         Material
-        .includes(:tag)
+        .includes(:tag, :material_export_items)
         .with_attached_file
         .find_by(id: params[:id])
     return head :not_found unless material
@@ -36,26 +39,38 @@ class MaterialsController < ApplicationController
 
   def create
     return head :unauthorized unless current_user
+    return head :forbidden unless current_user.gte_member?
 
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
+    file_sha256 = MaterialFileSha256.from_upload(file)
     url = params[:url].to_s.strip.presence
     return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
     if file.blank? && url.blank?
       return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
                                                url: ['ファイルまたは URL は必須です．'] }
     end
+    block = MaterialImportBlockMatcher.match_for_sha256(file_sha256)
+    return render_material_import_block(block) if block
 
-    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
-    tag = tag_name.tag
-    tag = Tag.create!(tag_name:, category: :material) unless tag
+    material = nil
+    Material.transaction do
+      tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+      tag = tag_name.tag
+      tag = Tag.create!(tag_name:, category: :material) unless tag
 
-    material = Material.new(tag:, url:,
-                            created_by_user: current_user,
-                            updated_by_user: current_user)
-    material.file.attach(file)
+      material = Material.new(tag:, url:,
+                              created_by_user: current_user,
+                              updated_by_user: current_user)
+      material.file.attach(file) if file
+      apply_file_sha256!(material, file_sha256)
+      material.save!
+      upsert_export_paths!(material)
+      MaterialVersionRecorder.record!(material:, event_type: :create,
+                                      created_by_user: current_user)
+    end
 
-    if material.save
+    if material
       render json: MaterialRepr.base(material, host: request.base_url), status: :created
     else
       render_validation_error material
@@ -71,29 +86,32 @@ class MaterialsController < ApplicationController
 
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
-    url = params[:url].to_s.strip.presence
+    file_sha256 = MaterialFileSha256.from_upload(file)
+    url = params.key?(:url) ? params[:url].to_s.strip.presence : material.url
     return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
-    if file.blank? && url.blank?
+    if file.blank? && url.blank? && !material.file.attached?
       return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
                                                url: ['ファイルまたは URL は必須です．'] }
     end
+    block = MaterialImportBlockMatcher.match_for_sha256(file_sha256)
+    return render_material_import_block(block) if block
 
-    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
-    tag = tag_name.tag
-    tag = Tag.create!(tag_name:, category: :material) unless tag
+    Material.transaction do
+      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
+      tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+      tag = tag_name.tag
+      tag = Tag.create!(tag_name:, category: :material) unless tag
 
-    material.update!(tag:, url:, updated_by_user: current_user)
-    if file
-      material.file.attach(file)
-    else
-      material.file.purge
+      material.update!(tag:, url:, updated_by_user: current_user)
+      material.file.attach(file) if file
+      apply_file_sha256!(material, file_sha256)
+      material.file.detach if params.key?(:url) && url.present? && file.blank?
+      upsert_export_paths!(material)
+      MaterialVersionRecorder.record!(material:, event_type: :update,
+                                      created_by_user: current_user)
     end
 
-    if material.save
-      render json: MaterialRepr.base(material, host: request.base_url)
-    else
-      render_validation_error material
-    end
+    render json: MaterialRepr.base(material, host: request.base_url)
   end
 
   def destroy
@@ -103,7 +121,111 @@ class MaterialsController < ApplicationController
     material = Material.find_by(id: params[:id])
     return head :not_found unless material
 
-    material.discard
+    Material.transaction do
+      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
+      material.discard!
+      MaterialVersionRecorder.record!(material:, event_type: :discard,
+                                      created_by_user: current_user)
+    end
     head :no_content
   end
+
+  def download
+    zip = MaterialZipExporter.new(profile: params[:profile],
+                                  tag_id: params[:tag_id]).export
+    profile = params[:profile].presence || 'legacy_drive'
+    send_data zip,
+              type: 'application/zip',
+              disposition: 'attachment',
+              filename: "btrc-materials-#{ profile }.zip"
+  end
+
+  def suppress_file
+    return head :unauthorized unless current_user
+    return head :forbidden unless current_user.admin?
+
+    material = Material.with_attached_file.find_by(id: params[:id])
+    return head :not_found unless material
+
+    reason = params[:reason].to_s.strip.presence
+    return render_unprocessable_entity('理由は必須です．', field: :reason) unless reason
+    purge = bool?(:purge)
+    file_snapshot = purge_material_file_snapshot(material) if purge
+    attachment = purge && material.file.attached? ? material.file.attachment : nil
+
+    Material.transaction do
+      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
+      material.update!(file_suppressed_at: Time.current,
+                       file_suppressed_by_user: current_user,
+                       file_suppression_reason: reason,
+                       updated_by_user: current_user)
+      MaterialVersionRecorder.record!(material:, event_type: :suppress,
+                                      created_by_user: current_user,
+                                      file_snapshot:)
+    end
+    # Enqueue failure raises here after the suppress metadata has been committed.
+    # In that case the file remains suppressed in UI/ZIP and purge can be retried.
+    attachment&.purge_later
+    material.reload if purge
+
+    render json: MaterialRepr.base(material, host: request.base_url)
+  end
+
+  private
+
+  def upsert_export_paths! material
+    raw = params[:export_paths]
+    return if raw.blank?
+
+    export_paths = raw.respond_to?(:to_unsafe_h) ? raw.to_unsafe_h : raw.to_h
+    export_paths.each do |profile, export_path|
+      profile = profile.to_s
+      export_path = export_path.to_s.strip
+      item = material.material_export_items.find_or_initialize_by(profile:)
+
+      if export_path.blank?
+        item.destroy! if item.persisted?
+        next
+      end
+
+      item.export_path = export_path
+      item.enabled = true
+      item.created_by_user ||= current_user
+      item.save!
+    end
+  end
+
+  def render_zip_empty
+    render_unprocessable_entity('ZIP export 対象の素材がありません．')
+  end
+
+  def render_zip_duplicate_path error
+    render_unprocessable_entity("ZIP export path が重複してゐます: #{ error.message }")
+  end
+
+  def apply_file_sha256! material, file_sha256
+    return if file_sha256.blank?
+    return unless material.file.attached?
+
+    blob = material.file.blob
+    blob.metadata['sha256'] = file_sha256
+    blob.save! if blob.changed?
+  end
+
+  def purge_material_file_snapshot material
+    return nil unless material.file.attached?
+
+    blob = material.file.blob
+
+    { file_blob_id: blob.id,
+      file_filename: blob.filename.to_s,
+      file_content_type: blob.content_type,
+      file_byte_size: blob.byte_size,
+      file_checksum: blob.checksum,
+      file_sha256: blob.metadata['sha256'] || MaterialFileSha256.from_blob(blob) }
+  end
+
+  def render_material_import_block block
+    render_validation_error fields: { file: ["抑止された素材です: #{ block.reason }"] }
+  end
 end

backend/app/controllers/posts_controller.rb

@@ -148,10 +148,10 @@ class PostsController < ApplicationController
     ApplicationRecord.transaction do
       post.save!
 
-      tags = Tag.normalise_tags!(tag_names)
+      tags = Tag.normalise_tags!(tag_names, deny_deprecated: true)
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
-      tags = Tag.expand_parent_tags(tags)
+      tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
       sync_post_tags!(post, tags)
 
       sync_parent_posts!(post, parent_post_ids)
@@ -165,6 +165,8 @@ class PostsController < ApplicationController
     render json: PostRepr.base(post), status: :created
   rescue Tag::NicoTagNormalisationError
     render_validation_error fields: { tags: 'ニコニコ・タグは直接指定できません．' }
+  rescue Tag::DeprecatedTagNormalisationError
+    render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
   rescue ArgumentError => e
     render_validation_error fields: { parent_post_ids: [e.message] }
   rescue ActiveRecord::RecordInvalid => e
@@ -255,6 +257,8 @@ class PostsController < ApplicationController
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
     render_validation_error fields: { tags: ['ニコニコ・タグは直接指定できません．'] }
+  rescue Tag::DeprecatedTagNormalisationError
+    render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
   rescue ArgumentError => e
     render_validation_error fields: { parent_post_ids: [e.message] }
   rescue ActiveRecord::RecordInvalid => e
@@ -378,7 +382,7 @@ class PostsController < ApplicationController
   end
 
   def build_tag_tree_for tags
-    tags = tags.to_a
+    tags = tags.reject(&:deprecated?).to_a
     tag_ids = tags.map(&:id)
 
     implications = TagImplication.where(parent_tag_id: tag_ids, tag_id: tag_ids)
@@ -501,7 +505,8 @@ class PostsController < ApplicationController
   end
 
   def editable_tag_names_from_post post
-    post.tags.not_nico.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+    post.tags.not_nico.where(deprecated_at: nil)
+        .joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
   end
 
   def post_incoming_snapshot title:, original_created_from:, original_created_before:,
@@ -533,9 +538,10 @@ class PostsController < ApplicationController
   end
 
   def incoming_tag_names_for_snapshot raw_tag_names
-    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false)
+    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false,
+                                              deny_deprecated: true)
 
-    Tag.expand_parent_tags(tags).map(&:name).uniq.sort
+    Tag.expand_parent_tags(tags).reject(&:deprecated?).map(&:name).uniq.sort
   end
 
   def post_conflict_json post:, base_version_no:, base_snapshot:,
@@ -622,13 +628,14 @@ class PostsController < ApplicationController
                  original_created_from: snapshot[:original_created_from],
                  original_created_before: snapshot[:original_created_before])
 
-    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false)
+    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false,
+                                                               deny_deprecated: true)
     TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
 
     readonly_tags = post.tags.nico.to_a
 
     tags = readonly_tags + editable_tags
-    tags = Tag.expand_parent_tags(tags)
+    tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
 
     sync_post_tags!(post, tags)
     sync_parent_posts!(post, snapshot[:parent_post_ids])

backend/app/controllers/tag_versions_controller.rb

@@ -17,6 +17,7 @@ class TagVersionsController < ApplicationController
               AND prev.version_no = tag_versions.version_no - 1
         SQL
       .select('tag_versions.*', 'prev.name AS prev_name', 'prev.category AS prev_category',
+              'prev.deprecated_at AS prev_deprecated_at',
               'prev.aliases AS prev_aliases', 'prev.parent_tag_ids AS prev_parent_tag_ids')
     q = q.where('tag_versions.tag_id = ?', tag_id) if tag_id
 
@@ -62,6 +63,8 @@ class TagVersionsController < ApplicationController
         event_type: row.event_type,
         name: { current: row.name, prev: row.attributes['prev_name'] },
         category: { current: row.category, prev: row.attributes['prev_category'] },
+        deprecated_at: { current: row.deprecated_at&.iso8601,
+                         prev: row.attributes['prev_deprecated_at']&.iso8601 },
         aliases: build_version_values(cur_aliases, prev_aliases, key: :name),
         parent_tags:,
         created_at: row.created_at.iso8601,

backend/app/controllers/tags_controller.rb

@@ -1,5 +1,6 @@
 require 'net/http'
 require 'uri'
+require 'set'
 
 
 class TagsController < ApplicationController
@@ -14,6 +15,8 @@ class TagsController < ApplicationController
     post_count_between[1] = nil if post_count_between[1] < 0
     created_between = params[:created_from].presence, params[:created_to].presence
     updated_between = params[:updated_from].presence, params[:updated_to].presence
+    deprecated_given = params.key?(:deprecated)
+    deprecated = bool?(:deprecated)
 
     order = params[:order].to_s.split(':', 2).map(&:strip)
     unless order[0].in?(['name', 'category', 'post_count', 'created_at', 'updated_at'])
@@ -48,6 +51,9 @@ class TagsController < ApplicationController
     q = q.where('tags.created_at <= ?', created_between[1]) if created_between[1]
     q = q.where('tags.updated_at >= ?', updated_between[0]) if updated_between[0]
     q = q.where('tags.updated_at <= ?', updated_between[1]) if updated_between[1]
+    if deprecated_given
+      q = deprecated ? q.where.not(deprecated_at: nil) : q.where(deprecated_at: nil)
+    end
 
     sort_sql =
         case order[0]
@@ -77,37 +83,27 @@ class TagsController < ApplicationController
     parent_tag_id = params[:parent].to_i
     parent_tag_id = nil if parent_tag_id <= 0
 
+    graph = build_with_depth_graph
+
     tag_ids =
         if parent_tag_id
-          TagImplication.where(parent_tag_id:).select(:tag_id)
+          visible_child_tag_ids(parent_tag_id, graph)
         else
-          Tag.where.not(id: TagImplication.select(:tag_id)).select(:id)
+          visible_root_tag_ids(graph)
         end
 
     tags =
         Tag
         .joins(:tag_name)
         .includes(:tag_name, :materials, tag_name: :wiki_page)
-        .where(category: [:meme, :character, :material])
         .where(id: tag_ids)
         .order('tag_names.name')
         .distinct
         .to_a
 
-    has_children_tag_ids =
-        if tags.empty?
-          []
-        else
-          TagImplication
-              .joins(:tag)
-              .where(parent_tag_id: tags.map(&:id),
-                     tags: { category: [:meme, :character, :material] })
-              .distinct
-              .pluck(:parent_tag_id)
-        end
-
     render json: tags.map { |tag|
-      TagRepr.base(tag).merge(has_children: has_children_tag_ids.include?(tag.id), children: [])
+      TagRepr.base(tag).merge(has_children: visible_child_tag_ids(tag.id, graph).present?,
+                              children: [])
     }
   end
 
@@ -133,6 +129,7 @@ class TagsController < ApplicationController
 
     base = Tag.joins(:tag_name)
               .includes(:tag_name, :materials, tag_name: :wiki_page)
+              .where(deprecated_at: nil)
     base = base.where('tags.post_count > 0') if present_only
 
     canonical_hit =
@@ -252,18 +249,24 @@ class TagsController < ApplicationController
     category = params[:category].to_s.strip
     return render_unprocessable_entity('名前は必須です．', field: :name) if name.blank?
     return render_unprocessable_entity('カテゴリは必須です．', field: :category) if category.blank?
+    return render_unprocessable_entity '廃止状態は必須です．', field: :deprecated unless params.key?(:deprecated)
 
-    if name != tag.name &&
-        tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico])
-      return render_unprocessable_entity('システム・タグの名称は変更できません．', field: :name)
-    end
-
-    if tag.nico? || category == 'nico'
-      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
+    if (name != tag.name &&
+        tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico]))
+      return render_unprocessable_entity 'システム・タグの名称は変更できません．', field: :name
     end
 
     alias_names = params[:aliases].to_s.split.uniq
     parent_names = params[:parent_tags].to_s.split.uniq
+    deprecated = bool?(:deprecated)
+
+    if tag.nico? && deprecated
+      return render_unprocessable_entity 'ニコタグは廃止できません．', field: :deprecated
+    end
+
+    if tag.nico? || category == 'nico'
+      return render_unprocessable_entity 'ニコタグは変更できません．', field: :category
+    end
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(tag, created_by_user: current_user)
@@ -272,7 +275,11 @@ class TagsController < ApplicationController
       name_changed = name != old_name
       wiki_page = tag.tag_name.wiki_page if name_changed
 
-      tag.update!(category:)
+      if tag.deprecated? == deprecated
+        tag.update!(category:)
+      else
+        tag.update!(category:, deprecated_at: deprecated ? Time.current : nil)
+      end
       tag.tag_name.update!(name:)
 
       alias_names << old_name if name_changed
@@ -300,11 +307,17 @@ class TagsController < ApplicationController
 
     name = params[:name].presence
     category = params[:category].presence
+    deprecated_given = params.key?(:deprecated)
+    deprecated = bool?(:deprecated)
 
     tag = Tag.find(params[:id])
 
+    if tag.nico? && deprecated_given && deprecated
+      return render_unprocessable_entity 'ニコタグは廃止できません．', field: :deprecated
+    end
+
     if tag.nico? || (category.present? && category == 'nico')
-      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
+      return render_unprocessable_entity 'ニコタグは変更できません．', field: :category
     end
 
     ApplicationRecord.transaction do
@@ -316,6 +329,9 @@ class TagsController < ApplicationController
 
       tag.tag_name.update!(name:) if name.present?
       tag.update!(category:) if category.present?
+      if deprecated_given && tag.deprecated? != deprecated
+        tag.update!(deprecated_at: deprecated ? Time.current : nil)
+      end
 
       tag.reload
 
@@ -332,18 +348,99 @@ class TagsController < ApplicationController
 
   private
 
+  def build_with_depth_graph
+    children_by_parent_id = Hash.new { |h, k| h[k] = [] }
+    parent_ids_by_child_id = Hash.new { |h, k| h[k] = [] }
+
+    TagImplication.pluck(:parent_tag_id, :tag_id).each do |parent_id, child_id|
+      children_by_parent_id[parent_id] << child_id
+      parent_ids_by_child_id[child_id] << parent_id
+    end
+
+    tag_ids = (children_by_parent_id.keys +
+               parent_ids_by_child_id.keys +
+               Tag.where(category: ['meme', 'character', 'material']).pluck(:id)).uniq
+
+    tags_by_id = Tag.where(id: tag_ids)
+                    .pluck(:id, :category, :deprecated_at)
+                    .each_with_object({ }) do |(id, category, deprecated_at), h|
+      h[id] = { category:, deprecated: deprecated_at.present? }
+    end
+
+    { children_by_parent_id:, parent_ids_by_child_id:, tags_by_id:,
+      visible_child_tag_ids_by_parent_id: { } }
+  end
+
+  def visible_root_tag_ids graph
+    graph[:tags_by_id].filter_map do |tag_id, attrs|
+      next unless with_depth_visible_tag?(attrs)
+      next unless visible_root_tag?(tag_id, graph)
+
+      tag_id
+    end
+  end
+
+  def visible_root_tag? tag_id, graph
+    seen = Set.new([tag_id])
+    stack = graph[:parent_ids_by_child_id][tag_id].dup
+
+    until stack.empty?
+      parent_id = stack.pop
+      next if seen.include?(parent_id)
+
+      seen << parent_id
+
+      parent = graph[:tags_by_id][parent_id]
+      next unless parent
+
+      return false unless parent[:deprecated]
+
+      stack.concat(graph[:parent_ids_by_child_id][parent_id])
+    end
+
+    true
+  end
+
+  def visible_child_tag_ids parent_tag_id, graph
+    cache = graph[:visible_child_tag_ids_by_parent_id]
+    return cache[parent_tag_id] if cache.key?(parent_tag_id)
+
+    visible_ids = Set.new
+
+    graph[:children_by_parent_id][parent_tag_id].each do |child_tag_id|
+      collect_visible_child_tag_ids(child_tag_id, graph, visible_ids, Set.new([parent_tag_id]))
+    end
+
+    cache[parent_tag_id] = visible_ids.to_a
+  end
+
+  def collect_visible_child_tag_ids tag_id, graph, visible_ids, seen
+    return if seen.include?(tag_id)
+
+    seen = seen.dup << tag_id
+    tag = graph[:tags_by_id][tag_id]
+    return unless tag
+
+    if tag[:deprecated]
+      graph[:children_by_parent_id][tag_id].each do |child_tag_id|
+        collect_visible_child_tag_ids(child_tag_id, graph, visible_ids, seen)
+      end
+      return
+    end
+
+    visible_ids << tag_id if with_depth_visible_tag?(tag)
+  end
+
+  def with_depth_visible_tag? tag
+    tag[:category].in?(['meme', 'character', 'material']) && !tag[:deprecated]
+  end
+
   def build_tag_children tag
     material = tag.materials.first
-    file = nil
-    content_type = nil
-    if material&.file&.attached?
-      file = rails_storage_proxy_url(material.file, only_path: false)
-      content_type = material.file.blob.content_type
-    end
 
     TagRepr.base(tag).merge(
         children: tag.children.sort_by { _1.name }.map { build_tag_children(_1) },
-        material: material.as_json&.merge(file:, content_type:))
+        material: material && MaterialRepr.base(material, host: request.base_url))
   end
 
   def record_tag_version! tag, event_type:, created_by_user:, name_changed: false, wiki_page: nil

backend/app/controllers/wiki_pages_controller.rb

@@ -4,17 +4,18 @@ class WikiPagesController < ApplicationController
   def index
     title = params[:title].to_s.strip
     if title.blank?
-      return render json: WikiPageRepr.base(WikiPage.joins(:tag_name).includes(:tag_name))
+      return render json: WikiPageRepr.base(
+          WikiPage.joins(:tag_name).includes(tag_name: :tag))
     end
 
-    q = WikiPage.joins(:tag_name).includes(:tag_name)
+    q = WikiPage.joins(:tag_name).includes(tag_name: :tag)
         .where('tag_names.name LIKE ?', "%#{ WikiPage.sanitize_sql_like(title) }%")
     render json: WikiPageRepr.base(q.limit(20))
   end
 
   def show
     page = WikiPage.joins(:tag_name)
-                   .includes(:tag_name)
+                   .includes(tag_name: :tag)
                    .find_by(id: params[:id])
     render_wiki_page_or_404 page
   end
@@ -22,7 +23,7 @@ class WikiPagesController < ApplicationController
   def show_by_title
     title = params[:title].to_s.strip
     page = WikiPage.joins(:tag_name)
-                   .includes(:tag_name)
+                   .includes(tag_name: :tag)
                    .find_by(tag_name: { name: title })
     render_wiki_page_or_404 page
   end
@@ -51,7 +52,7 @@ class WikiPagesController < ApplicationController
     from = params[:from].presence
     to = params[:to].presence
 
-    page = WikiPage.joins(:tag_name).includes(:tag_name).find(id)
+    page = WikiPage.joins(:tag_name).includes(tag_name: :tag).find(id)
 
     from_rev = from && page.wiki_revisions.find(from)
     to_rev = to ? page.wiki_revisions.find(to) : page.current_revision
@@ -76,6 +77,7 @@ class WikiPagesController < ApplicationController
 
     render json: { wiki_page_id:      page.id,
                    title:             page.title,
+                   deprecated_at:     page.deprecated_at,
                    older_revision_id: from_rev&.id,
                    newer_revision_id: to_rev.id,
                    diff:              diff_json }
@@ -157,7 +159,7 @@ class WikiPagesController < ApplicationController
   def changes
     id = params[:id].presence
     q = WikiRevision.joins(wiki_page: :tag_name)
-                    .includes(:created_user, wiki_page: :tag_name)
+                    .includes(:created_user, wiki_page: { tag_name: :tag })
                     .order(id: :desc)
     q = q.where(wiki_page_id: id) if id
 
@@ -165,7 +167,9 @@ class WikiPagesController < ApplicationController
       { revision_id:  rev.id,
         pred:         rev.base_revision_id,
         succ:         nil,
-        wiki_page:    { id: rev.wiki_page_id, title: rev.wiki_page.title },
+        wiki_page:    { id: rev.wiki_page_id,
+                        title: rev.wiki_page.title,
+                        deprecated_at: rev.wiki_page.deprecated_at },
         user:         rev.created_user && { id: rev.created_user.id, name: rev.created_user.name },
         kind:         rev.kind,
         message:      rev.message,

backend/app/models/material.rb

@@ -9,6 +9,10 @@ class Material < ApplicationRecord
   belongs_to :tag, optional: true
   belongs_to :created_by_user, class_name: 'User', optional: true
   belongs_to :updated_by_user, class_name: 'User', optional: true
+  belongs_to :file_suppressed_by_user, class_name: 'User', optional: true
+
+  has_many :material_versions, dependent: :destroy
+  has_many :material_export_items, dependent: :destroy
 
   has_one_attached :file, dependent: :purge
 
@@ -18,11 +22,18 @@ class Material < ApplicationRecord
   validate :tag_must_be_material_category
 
   def content_type
+    return nil if file_suppressed?
     return nil unless file&.attached?
 
     file.blob.content_type
   end
 
+  def file_suppressed? = file_suppressed_at.present?
+
+  def snapshot_export_paths
+    material_export_items.order(:profile).pluck(:profile, :export_path).to_h
+  end
+
   private
 
   def file_must_be_attached

backend/app/models/material_export_item.rb

@@ -0,0 +1,48 @@
+class MaterialExportItem < ApplicationRecord
+  VALID_PROFILES = ['legacy_drive'].freeze
+
+  belongs_to :material
+  belongs_to :created_by_user, class_name: 'User', optional: true
+
+  validates :profile, presence: true, inclusion: { in: VALID_PROFILES }
+  validates :export_path, presence: true, uniqueness: { scope: :profile }
+  validates :material_id, uniqueness: { scope: :profile }
+  validate :export_path_must_be_relative_safe_path
+
+  scope :enabled, -> { where(enabled: true) }
+
+  private
+
+  def export_path_must_be_relative_safe_path
+    return if export_path.blank?
+
+    if export_path.start_with?('/')
+      errors.add(:export_path, '絶対パスは使へません．')
+    end
+
+    if export_path.match?(/\A[A-Za-z]:\//)
+      errors.add(:export_path, '絶対パスは使へません．')
+    end
+
+    if export_path.include?('\\')
+      errors.add(:export_path, '/ 区切りで指定してください．')
+    end
+
+    if export_path.include?("\0")
+      errors.add(:export_path, 'NUL は使へません．')
+    end
+
+    parts = export_path.split('/')
+    if export_path.include?('//')
+      errors.add(:export_path, '空の path segment は使へません．')
+    end
+
+    if parts.any? { |part| part.in?(['.', '..']) }
+      errors.add(:export_path, '.. は使へません．')
+    end
+
+    if export_path.end_with?('/')
+      errors.add(:export_path, 'directory path は使へません．')
+    end
+  end
+end

backend/app/models/material_import_block.rb

@@ -0,0 +1,29 @@
+class MaterialImportBlock < ApplicationRecord
+  MATCH_KINDS = ['sha256', 'exact_path', 'path_prefix', 'manual'].freeze
+  REASONS = [
+    'copyright_high_risk',
+    'copyright_takedown',
+    'adult_or_sensitive',
+    'personal_information',
+    'malware_or_dangerous_file',
+    'duplicate_or_low_quality',
+    'source_owner_request',
+    'other'
+  ].freeze
+
+  belongs_to :created_by_user, class_name: 'User', optional: true
+
+  validates :match_kind, presence: true, inclusion: { in: MATCH_KINDS }
+  validates :reason, presence: true, inclusion: { in: REASONS }
+  validates :sha256, length: { is: 64 }, allow_blank: true
+  validate :match_value_must_be_present
+
+  private
+
+  def match_value_must_be_present
+    return if match_kind == 'manual'
+    return if sha256.present? || external_path_pattern.present?
+
+    errors.add(:base, 'sha256 または external_path_pattern は必須です．')
+  end
+end

backend/app/models/material_version.rb

@@ -0,0 +1,18 @@
+class MaterialVersion < ApplicationRecord
+  EVENT_TYPE_MAP = { create: 'create',
+                     update: 'update',
+                     discard: 'discard',
+                     restore: 'restore',
+                     suppress: 'suppress' }.freeze
+
+  include VersionRecord
+
+  belongs_to :material
+  belongs_to :tag, optional: true
+  belongs_to :parent, class_name: 'Material', optional: true
+  belongs_to :updated_by_user, class_name: 'User', optional: true
+
+  def export_paths_hash
+    export_paths_json || {}
+  end
+end

backend/app/models/post.rb

@@ -7,6 +7,8 @@ class Post < ApplicationRecord
   has_many :active_post_tags, -> { kept }, class_name: 'PostTag', inverse_of: :post
   has_many :post_tags_with_discarded, -> { with_discarded }, class_name: 'PostTag'
   has_many :tags, through: :active_post_tags
+  has_many :active_tags, -> { where(tags: { deprecated_at: nil }) },
+           through: :active_post_tags, source: :tag
 
   has_many :user_post_views, dependent: :delete_all
   has_many :post_similarities, dependent: :delete_all

backend/app/models/tag.rb

@@ -8,6 +8,15 @@ class Tag < ApplicationRecord
     ;
   end
 
+  class DeprecatedTagNormalisationError < ArgumentError
+    attr_reader :tag_names
+
+    def initialize tag_names
+      @tag_names = Array(tag_names)
+      super('deprecated tags are not allowed')
+    end
+  end
+
   has_many :post_tags, inverse_of: :tag
   has_many :active_post_tags, -> { kept }, class_name: 'PostTag', inverse_of: :tag
   has_many :post_tags_with_discarded, -> { with_discarded }, class_name: 'PostTag'
@@ -58,6 +67,7 @@ class Tag < ApplicationRecord
   validate :nico_tag_name_must_start_with_nico
   validate :tag_name_must_be_canonical
   validate :category_must_be_deerjikist_with_deerjikists
+  validate :nico_tags_cannot_be_deprecated
 
   scope :nico_tags, -> { nico }
 
@@ -77,6 +87,8 @@ class Tag < ApplicationRecord
     (self.tag_name ||= build_tag_name).name = val
   end
 
+  def deprecated? = deprecated_at?
+
   def has_wiki = wiki_page.present?
 
   def material_id = materials.first&.id
@@ -92,7 +104,8 @@ class Tag < ApplicationRecord
 
   def self.normalise_tags! tag_names, with_tagme: true,
                                       with_no_deerjikist: true,
-                                      deny_nico: true
+                                      deny_nico: true,
+                                      deny_deprecated: false
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end
@@ -101,6 +114,10 @@ class Tag < ApplicationRecord
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
       name = TagName.canonicalise(name.sub(/\A#{ pf }/i, '')).first
       find_or_create_by_tag_name!(name, category: (cat || :general)).tap do |tag|
+        if deny_deprecated && tag.deprecated?
+          raise DeprecatedTagNormalisationError, [tag.name]
+        end
+
         tag.update!(category: cat) if cat && tag.category != cat
       end
     end
@@ -228,4 +245,10 @@ class Tag < ApplicationRecord
       errors.add :category, 'ニジラーと紐づいてゐるタグはニジラー・カテゴリである必要があります．'
     end
   end
+
+  def nico_tags_cannot_be_deprecated
+    if nico? && deprecated_at.present?
+      errors.add :deprecated_at, 'ニコタグは廃止できません．'
+    end
+  end
 end

backend/app/models/version_record.rb

@@ -1,15 +1,23 @@
 module VersionRecord
   extend ActiveSupport::Concern
 
+  DEFAULT_EVENT_TYPE_MAP = { create: 'create',
+                             update: 'update',
+                             discard: 'discard',
+                             restore: 'restore' }.freeze
+
   def readonly? = persisted?
 
   included do
+    event_type_map = if const_defined?(:EVENT_TYPE_MAP, false)
+                       const_get(:EVENT_TYPE_MAP)
+                     else
+                       DEFAULT_EVENT_TYPE_MAP
+                     end
+
     belongs_to :created_by_user, class_name: 'User', optional: true
 
-    enum :event_type, { create: 'create',
-                        update: 'update',
-                        discard: 'discard',
-                        restore: 'restore' }, prefix: true, validate: true
+    enum :event_type, event_type_map, prefix: true, validate: true
 
     validates :version_no, presence: true, numericality: { only_integer: true, greater_than: 0 }
     validates :event_type, presence: true

backend/app/models/wiki_page.rb

@@ -22,6 +22,7 @@ class WikiPage < ApplicationRecord
   validates :body, presence: true
 
   def title = tag_name.name
+  def deprecated_at = tag_name.tag&.deprecated_at
 
   def title= val
     (self.tag_name ||= build_tag_name).name = val

backend/app/representations/material_repr.rb

@@ -2,7 +2,8 @@
 
 
 module MaterialRepr
-  BASE = { only: [:id, :url, :created_at, :updated_at],
+  BASE = { only: [:id, :url, :version_no, :file_suppressed_at,
+                  :file_suppression_reason, :created_at, :updated_at],
            methods: [:content_type],
            include: { tag: TagRepr::BASE,
                       created_by_user: UserRepr::BASE,
@@ -12,13 +13,30 @@ module MaterialRepr
 
   def base material, host:
     material.as_json(BASE).merge(
-        file: if material.file.attached?
+        file: if material.file.attached? && !material.file_suppressed?
                 Rails.application.routes.url_helpers.rails_storage_proxy_url(
                     material.file, host:)
-              end)
+              end,
+        export_paths: export_paths(material),
+        export_items: export_items(material))
   end
 
   def many materials, host:
     materials.map { |m| base(m, host:) }
   end
+
+  def export_paths material
+    material.material_export_items.each_with_object({ }) do |item, hash|
+      hash[item.profile] = item.enabled ? item.export_path : ''
+    end
+  end
+
+  def export_items material
+    material.material_export_items.map do |item|
+      { id: item.id,
+        profile: item.profile,
+        export_path: item.export_path,
+        enabled: item.enabled }
+    end
+  end
 end

backend/app/representations/post_repr.rb

@@ -53,7 +53,7 @@ module PostRepr
   end
 
   def tag_json tags
-    tags.map { |tag| TagRepr.inline(tag) }
+    tags.reject(&:deprecated?).map { |tag| TagRepr.inline(tag) }
   end
 
   def thumbnail_url post

backend/app/representations/tag_repr.rb

@@ -2,7 +2,7 @@
 
 
 module TagRepr
-  BASE = { only: [:id, :category, :post_count, :created_at, :updated_at],
+  BASE = { only: [:id, :category, :post_count, :created_at, :updated_at, :deprecated_at],
            methods: [:name, :has_wiki, :material_id, :has_deerjikists] }.freeze
 
   module_function

backend/app/representations/wiki_page_repr.rb

@@ -2,7 +2,7 @@
 
 
 module WikiPageRepr
-  BASE = { methods: [:title] }.freeze
+  BASE = { methods: [:title, :deprecated_at] }.freeze
 
   module_function
 

backend/app/services/material_file_sha256.rb

@@ -0,0 +1,25 @@
+require 'digest'
+
+class MaterialFileSha256
+  def self.from_blob blob
+    sha256 = blob.metadata['sha256']
+    return sha256 if sha256.present?
+
+    blob.open do |file|
+      sha256 = Digest::SHA256.file(file.path).hexdigest
+      blob.metadata['sha256'] = sha256
+      blob.save! if blob.changed?
+      sha256
+    end
+  end
+
+  def self.from_upload upload
+    tempfile = upload&.tempfile
+    return nil unless tempfile
+
+    tempfile.rewind
+    Digest::SHA256.file(tempfile.path).hexdigest.tap do
+      tempfile.rewind
+    end
+  end
+end

backend/app/services/material_import_block_matcher.rb

@@ -0,0 +1,7 @@
+class MaterialImportBlockMatcher
+  def self.match_for_sha256 sha256
+    return nil if sha256.blank?
+
+    MaterialImportBlock.find_by(match_kind: 'sha256', sha256:)
+  end
+end

backend/app/services/material_version_recorder.rb

@@ -0,0 +1,73 @@
+class MaterialVersionRecorder < VersionRecorder
+  EVENT_TYPES = ['create', 'update', 'discard', 'restore', 'suppress'].freeze
+
+  def self.record! material:, event_type:, created_by_user:, file_snapshot: nil
+    new(material:, event_type:, created_by_user:, file_snapshot:).record!
+  end
+
+  def initialize material:, event_type:, created_by_user:, file_snapshot: nil
+    @file_snapshot = file_snapshot
+
+    super(record: material, event_type:, created_by_user:)
+  end
+
+  def self.ensure_snapshot! material, created_by_user:
+    return if material.material_versions.exists?
+
+    record!(material:, event_type: :create,
+            created_by_user: material.created_by_user || created_by_user)
+  end
+
+  private
+
+  def version_class = MaterialVersion
+  def version_association = :material_versions
+  def record_key = :material
+
+  def snapshot_attributes
+    blob = @record.file.attached? ? @record.file.blob : nil
+    file_snapshot = build_file_snapshot(blob)
+
+    { url: @record.url,
+      parent: @record.parent,
+      tag: @record.tag,
+      tag_name: @record.tag&.name,
+      tag_category: @record.tag&.category,
+      export_paths_json: @record.snapshot_export_paths,
+      discarded_at: @record.discarded_at,
+      file_blob_id: file_snapshot[:file_blob_id],
+      file_filename: file_snapshot[:file_filename],
+      file_content_type: file_snapshot[:file_content_type],
+      file_byte_size: file_snapshot[:file_byte_size],
+      file_checksum: file_snapshot[:file_checksum],
+      file_sha256: file_snapshot[:file_sha256],
+      file_suppressed_at: @record.file_suppressed_at,
+      file_suppression_reason: @record.file_suppression_reason }
+  end
+
+  def build_file_snapshot blob
+    return @file_snapshot if @file_snapshot
+    return empty_file_snapshot unless blob
+
+    blob.metadata['sha256'] ||= MaterialFileSha256.from_blob(blob)
+    blob.save! if blob.changed?
+
+    { file_blob_id: blob.id,
+      file_filename: blob.filename.to_s,
+      file_content_type: blob.content_type,
+      file_byte_size: blob.byte_size,
+      file_checksum: blob.checksum,
+      file_sha256: blob.metadata['sha256'] }
+  end
+
+  def empty_file_snapshot
+    { file_blob_id: nil,
+      file_filename: nil,
+      file_content_type: nil,
+      file_byte_size: nil,
+      file_checksum: nil,
+      file_sha256: nil }
+  end
+
+  def event_types = self.class::EVENT_TYPES
+end

backend/app/services/material_zip_exporter.rb

@@ -0,0 +1,118 @@
+require 'stringio'
+require 'zlib'
+
+# Initial implementation keeps every file payload and the final ZIP in memory.
+# Keep this service boundary stable so job/cached export paths can replace it later.
+class MaterialZipExporter
+  Entry = Struct.new(:path, :data, :mtime, keyword_init: true)
+
+  class EmptyExportError < StandardError; end
+  class DuplicatePathError < StandardError; end
+
+  def initialize profile: 'legacy_drive', tag_id: nil
+    @profile = profile.presence || 'legacy_drive'
+    @tag_id = tag_id.presence
+  end
+
+  def export
+    entries = build_entries
+    raise EmptyExportError if entries.empty?
+
+    ZipWriter.write(entries)
+  end
+
+  private
+
+  def build_entries
+    rows = MaterialExportItem
+           .enabled
+           .includes(material: { file_attachment: :blob })
+           .joins(:material)
+           .merge(Material.kept)
+           .where(profile: @profile)
+           .where(materials: { file_suppressed_at: nil })
+           .order(:export_path)
+
+    rows = rows.where(materials: { tag_id: @tag_id }) if @tag_id
+
+    entries = rows.filter_map do |item|
+      material = item.material
+      next unless material.file.attached?
+
+      Entry.new(path: item.export_path,
+                data: material.file.blob.download,
+                mtime: material.updated_at || Time.current)
+    end
+
+    paths = entries.map(&:path)
+    duplicated = paths.find { |path| paths.count(path) > 1 }
+    raise DuplicatePathError, duplicated if duplicated
+
+    entries
+  end
+
+  class ZipWriter
+    VERSION_NEEDED = 20
+    GP_FLAG = 0x0800
+    COMPRESSION_STORE = 0
+
+    def self.write entries
+      new(entries).write
+    end
+
+    def initialize entries
+      @entries = entries
+      @central_directory = []
+    end
+
+    def write
+      io = StringIO.new(''.b)
+
+      @entries.each do |entry|
+        write_entry(io, entry)
+      end
+
+      central_start = io.pos
+      @central_directory.each { |header| io.write(header) }
+      central_size = io.pos - central_start
+
+      io.write([0x06054b50, 0, 0, @entries.size, @entries.size,
+                central_size, central_start, 0].pack('VvvvvVVv'))
+      io.string
+    end
+
+    private
+
+    def write_entry io, entry
+      path = entry.path.b
+      data = entry.data.b
+      crc32 = Zlib.crc32(data)
+      dos_time, dos_date = dos_timestamp(entry.mtime)
+      offset = io.pos
+
+      local_header = [0x04034b50, VERSION_NEEDED, GP_FLAG, COMPRESSION_STORE,
+                      dos_time, dos_date, crc32, data.bytesize, data.bytesize,
+                      path.bytesize, 0].pack('VvvvvvVVVvv')
+
+      io.write(local_header)
+      io.write(path)
+      io.write(data)
+
+      @central_directory << central_header(path:, crc32:, size: data.bytesize,
+                                           dos_time:, dos_date:, offset:)
+    end
+
+    def central_header path:, crc32:, size:, dos_time:, dos_date:, offset:
+      [0x02014b50, VERSION_NEEDED, VERSION_NEEDED, GP_FLAG, COMPRESSION_STORE,
+       dos_time, dos_date, crc32, size, size, path.bytesize, 0, 0, 0, 0, 0,
+       offset].pack('VvvvvvvVVVvvvvvVV') + path
+    end
+
+    def dos_timestamp time
+      local = time.to_time
+      dos_time = (local.hour << 11) | (local.min << 5) | (local.sec / 2)
+      dos_date = ((local.year - 1980) << 9) | (local.month << 5) | local.day
+      [dos_time, dos_date]
+    end
+  end
+end

backend/app/services/similarity/calc.rb

@@ -1,6 +1,6 @@
 module Similarity
   class Calc
-    def self.call model, tgt
+    def self.call model, tgt, scope: nil
       similarity_model = "#{ model.name }Similarity".constantize
 
       # 最大保存件数
@@ -8,7 +8,8 @@ module Similarity
 
       similarity_model.delete_all
 
-      posts = model.includes(tgt).select(:id).to_a
+      scope ||= model.all
+      posts = scope.includes(tgt).select(:id).to_a
 
       tag_ids = { }
       tag_cnts = { }

backend/app/services/tag_version_recorder.rb

@@ -16,6 +16,7 @@ class TagVersionRecorder < VersionRecorder
   def snapshot_attributes
     { name: @record.name,
       category: @record.category,
+      deprecated_at: @record.deprecated_at,
       aliases: @record.snapshot_aliases.join(' '),
       parent_tag_ids: @record.snapshot_parent_tag_ids.join(' ') }
   end

backend/app/services/version_recorder.rb

@@ -73,7 +73,7 @@ class VersionRecorder
   end
 
   def validate_event_type!
-    return if EVENT_TYPES.include?(@event_type)
+    return if event_types.include?(@event_type)
 
     raise ArgumentError, "Invalid event_type: #{ @event_type }"
   end
@@ -84,4 +84,5 @@ class VersionRecorder
   def snapshot_attributes = raise NotImplementedError
 
   def record_class = @record.class
+  def event_types = self.class::EVENT_TYPES
 end

backend/config/routes.rb

@@ -113,5 +113,10 @@ Rails.application.routes.draw do
     resources :skip_events, controller: :theatre_skip_events, only: [:index]
   end
 
-  resources :materials, only: [:index, :show, :create, :update, :destroy]
+  get 'materials/download.zip', to: 'materials#download'
+  resources :materials, only: [:index, :show, :create, :update, :destroy] do
+    member do
+      patch :suppress_file
+    end
+  end
 end

backend/db/migrate/20260621000000_add_deprecated_at_to_tags.rb

@@ -0,0 +1,20 @@
+class AddDeprecatedAtToTags < ActiveRecord::Migration[8.0]
+  def up
+    add_column :tags, :deprecated_at, :datetime, after: :category
+    add_column :tag_versions, :deprecated_at, :datetime, after: :parent_tag_ids
+
+    add_index :tags, :deprecated_at
+
+    add_check_constraint :tags, "deprecated_at IS NULL OR category <> 'nico'",
+                         name: 'chk_tags_deprecated_at_not_nico'
+  end
+
+  def down
+    remove_check_constraint :tags, name: 'chk_tags_deprecated_at_not_nico'
+
+    remove_index :tags, :deprecated_at
+
+    remove_column :tag_versions, :deprecated_at, :datetime
+    remove_column :tags, :deprecated_at
+  end
+end

backend/db/migrate/20260623000000_enhance_material_management.rb

@@ -0,0 +1,98 @@
+class EnhanceMaterialManagement < ActiveRecord::Migration[8.0]
+  def up
+    change_table :materials, bulk: true do |t|
+      t.integer :version_no, null: false, default: 1
+      t.datetime :file_suppressed_at
+      t.references :file_suppressed_by_user, foreign_key: { to_table: :users }
+      t.string :file_suppression_reason
+    end
+
+    change_table :material_versions, bulk: true do |t|
+      t.string :event_type
+      t.string :tag_name
+      t.string :tag_category
+      t.json :export_paths_json
+      t.bigint :file_blob_id
+      t.string :file_filename
+      t.string :file_content_type
+      t.bigint :file_byte_size
+      t.string :file_checksum
+      t.string :file_sha256
+      t.datetime :file_suppressed_at
+      t.string :file_suppression_reason
+    end
+
+    execute <<~SQL.squish
+      UPDATE material_versions
+      SET event_type = CASE
+                       WHEN version_no = 1 THEN 'create'
+                       ELSE 'update'
+                       END
+      WHERE event_type IS NULL
+    SQL
+
+    change_column_null :material_versions, :event_type, false
+    add_index :material_versions, :file_blob_id
+
+    add_check_constraint :material_versions,
+                         "event_type IN ('create', 'update', 'discard', 'restore', 'suppress')",
+                         name: 'material_versions_event_type_valid'
+
+    create_table :material_export_items do |t|
+      t.references :material, null: false, foreign_key: true
+      t.string :profile, null: false, default: 'legacy_drive'
+      t.string :export_path, null: false
+      t.boolean :enabled, null: false, default: true
+      t.references :created_by_user, foreign_key: { to_table: :users }
+      t.timestamps
+
+      t.index [:profile, :export_path], unique: true
+      t.index [:material_id, :profile], unique: true
+    end
+
+    create_table :material_import_blocks do |t|
+      t.string :match_kind, null: false
+      t.string :sha256
+      t.string :external_path_pattern
+      t.string :reason, null: false
+      t.text :note
+      t.references :created_by_user, foreign_key: { to_table: :users }
+      t.timestamps
+    end
+
+    execute <<~SQL.squish
+      UPDATE materials
+      SET version_no = COALESCE(
+        (SELECT MAX(material_versions.version_no)
+         FROM material_versions
+         WHERE material_versions.material_id = materials.id),
+        1)
+    SQL
+  end
+
+  def down
+    drop_table :material_import_blocks
+    drop_table :material_export_items
+
+    remove_check_constraint :material_versions, name: 'material_versions_event_type_valid'
+
+    remove_index :material_versions, :file_blob_id
+    remove_column :material_versions, :event_type
+    remove_column :material_versions, :tag_name
+    remove_column :material_versions, :tag_category
+    remove_column :material_versions, :export_paths_json
+    remove_column :material_versions, :file_blob_id
+    remove_column :material_versions, :file_filename
+    remove_column :material_versions, :file_content_type
+    remove_column :material_versions, :file_byte_size
+    remove_column :material_versions, :file_checksum
+    remove_column :material_versions, :file_sha256
+    remove_column :material_versions, :file_suppressed_at
+    remove_column :material_versions, :file_suppression_reason
+
+    remove_reference :materials, :file_suppressed_by_user, foreign_key: { to_table: :users }
+    remove_column :materials, :version_no
+    remove_column :materials, :file_suppressed_at
+    remove_column :materials, :file_suppression_reason
+  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_23_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
@@ -130,6 +130,32 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.index ["ip_address"], name: "index_ip_addresses_on_ip_address", unique: true
   end
 
+  create_table "material_export_items", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.bigint "material_id", null: false
+    t.string "profile", default: "legacy_drive", null: false
+    t.string "export_path", null: false
+    t.boolean "enabled", default: true, null: false
+    t.bigint "created_by_user_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["created_by_user_id"], name: "index_material_export_items_on_created_by_user_id"
+    t.index ["material_id", "profile"], name: "index_material_export_items_on_material_id_and_profile", unique: true
+    t.index ["material_id"], name: "index_material_export_items_on_material_id"
+    t.index ["profile", "export_path"], name: "index_material_export_items_on_profile_and_export_path", unique: true
+  end
+
+  create_table "material_import_blocks", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.string "match_kind", null: false
+    t.string "sha256"
+    t.string "external_path_pattern"
+    t.string "reason", null: false
+    t.text "note"
+    t.bigint "created_by_user_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["created_by_user_id"], name: "index_material_import_blocks_on_created_by_user_id"
+  end
+
   create_table "material_versions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "material_id", null: false
     t.integer "version_no", null: false
@@ -141,14 +167,28 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.datetime "discarded_at"
+    t.string "event_type", null: false
+    t.string "tag_name"
+    t.string "tag_category"
+    t.json "export_paths_json"
+    t.bigint "file_blob_id"
+    t.string "file_filename"
+    t.string "file_content_type"
+    t.bigint "file_byte_size"
+    t.string "file_checksum"
+    t.string "file_sha256"
+    t.datetime "file_suppressed_at"
+    t.string "file_suppression_reason"
     t.index ["created_by_user_id"], name: "index_material_versions_on_created_by_user_id"
     t.index ["discarded_at"], name: "index_material_versions_on_discarded_at"
+    t.index ["file_blob_id"], name: "index_material_versions_on_file_blob_id"
     t.index ["material_id", "version_no"], name: "index_material_versions_on_material_id_and_version_no", unique: true
     t.index ["material_id"], name: "index_material_versions_on_material_id"
     t.index ["parent_id"], name: "index_material_versions_on_parent_id"
     t.index ["tag_id"], name: "index_material_versions_on_tag_id"
     t.index ["updated_by_user_id"], name: "index_material_versions_on_updated_by_user_id"
     t.index ["url"], name: "index_material_versions_on_url"
+    t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore',_utf8mb4'suppress')", name: "material_versions_event_type_valid"
   end
 
   create_table "materials", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -161,9 +201,14 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.datetime "updated_at", null: false
     t.datetime "discarded_at"
     t.virtual "active_url", type: :string, as: "if((`discarded_at` is null),`url`,NULL)"
+    t.integer "version_no", default: 1, null: false
+    t.datetime "file_suppressed_at"
+    t.bigint "file_suppressed_by_user_id"
+    t.string "file_suppression_reason"
     t.index ["active_url"], name: "index_materials_on_active_url", unique: true
     t.index ["created_by_user_id"], name: "index_materials_on_created_by_user_id"
     t.index ["discarded_at"], name: "index_materials_on_discarded_at"
+    t.index ["file_suppressed_by_user_id"], name: "index_materials_on_file_suppressed_by_user_id"
     t.index ["parent_id"], name: "index_materials_on_parent_id"
     t.index ["tag_id"], name: "index_materials_on_tag_id"
     t.index ["updated_by_user_id"], name: "index_materials_on_updated_by_user_id"
@@ -319,6 +364,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.string "event_type", null: false
     t.string "name", null: false
     t.string "category", null: false
+    t.datetime "deprecated_at"
     t.text "aliases", null: false
     t.text "parent_tag_ids", null: false
     t.datetime "created_at", null: false
@@ -336,10 +382,13 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.integer "post_count", default: 0, null: false
+    t.datetime "deprecated_at"
     t.datetime "discarded_at"
     t.integer "version_no", null: false
+    t.index ["deprecated_at"], name: "index_tags_on_deprecated_at"
     t.index ["discarded_at"], name: "index_tags_on_discarded_at"
     t.index ["tag_name_id"], name: "index_tags_on_tag_name_id", unique: true
+    t.check_constraint "(`deprecated_at` is null) or (`category` <> _utf8mb4'nico')", name: "chk_tags_deprecated_at_not_nico"
     t.check_constraint "`version_no` > 0", name: "chk_tags_version_no_positive"
   end
 
@@ -563,6 +612,9 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
   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_export_items", "materials"
+  add_foreign_key "material_export_items", "users", column: "created_by_user_id"
+  add_foreign_key "material_import_blocks", "users", column: "created_by_user_id"
   add_foreign_key "material_versions", "materials"
   add_foreign_key "material_versions", "materials", column: "parent_id"
   add_foreign_key "material_versions", "tags"
@@ -571,6 +623,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_12_000000) do
   add_foreign_key "materials", "materials", column: "parent_id"
   add_foreign_key "materials", "tags"
   add_foreign_key "materials", "users", column: "created_by_user_id"
+  add_foreign_key "materials", "users", column: "file_suppressed_by_user_id"
   add_foreign_key "materials", "users", column: "updated_by_user_id"
   add_foreign_key "nico_tag_relations", "tags"
   add_foreign_key "nico_tag_relations", "tags", column: "nico_tag_id"

backend/lib/tasks/calc_post_similarities.rake

@@ -1,6 +1,6 @@
 namespace :post_similarity do
   desc '関聯投稿テーブル作成'
   task calc: :environment do
-    Similarity::Calc.call(Post, :tags)
+    Similarity::Calc.call(Post, :active_tags)
   end
 end

backend/lib/tasks/calc_tag_similarities.rake

@@ -1,6 +1,6 @@
 namespace :tag_similarity do
   desc '関聯タグ・テーブル作成'
   task calc: :environment do
-    Similarity::Calc.call(Tag, :posts)
+    Similarity::Calc.call(Tag, :posts, scope: Tag.where(deprecated_at: nil))
   end
 end

backend/spec/models/material_export_item_spec.rb

@@ -0,0 +1,57 @@
+require 'rails_helper'
+
+RSpec.describe MaterialExportItem, type: :model do
+  let(:user) { create(:user, :member) }
+  let(:tag) { Tag.create!(tag_name: TagName.create!(name: 'export_item'), category: :material) }
+  let(:material) do
+    Material.create!(tag:, url: 'https://example.com/material',
+                     created_by_user: user, updated_by_user: user)
+  end
+
+  it 'rejects blank export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive', export_path: '')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+
+  it 'rejects absolute export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive',
+                               export_path: '/素材/a.png')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+
+  it 'rejects parent traversal export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive',
+                               export_path: '素材/../a.png')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+
+  it 'rejects double slash export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive',
+                               export_path: '素材//a.png')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+
+  it 'rejects dot segment export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive',
+                               export_path: './素材/a.png')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+
+  it 'rejects trailing slash export_path' do
+    item = described_class.new(material:, profile: 'legacy_drive',
+                               export_path: '素材/a/')
+
+    expect(item).not_to be_valid
+    expect(item.errors[:export_path]).to be_present
+  end
+end

backend/spec/models/tag_spec.rb

@@ -1,6 +1,79 @@
 require 'rails_helper'
 
 RSpec.describe Tag, type: :model do
+  describe '.normalise_tags!' do
+    it 'rejects deprecated tags when deny_deprecated is enabled' do
+      tag_name = TagName.create!(name: 'normalise deprecated tag')
+      deprecated_tag = Tag.create!(
+        tag_name:,
+        category: :general,
+        deprecated_at: 1.day.from_now
+      )
+
+      expect {
+        described_class.normalise_tags!(
+          [deprecated_tag.name],
+          deny_deprecated: true
+        )
+      }.to raise_error(Tag::DeprecatedTagNormalisationError) { |error|
+        expect(error.tag_names).to eq([deprecated_tag.name])
+      }
+    end
+  end
+
+  describe '.expand_parent_tags' do
+    it 'expands through multiple deprecated parents to an active ancestor' do
+      child = create(:tag, name: 'expand_child')
+      deprecated_parent = create(
+        :tag,
+        name: 'expand_deprecated_parent',
+        deprecated_at: Time.current
+      )
+      deprecated_grandparent = create(
+        :tag,
+        name: 'expand_deprecated_grandparent',
+        deprecated_at: Time.current
+      )
+      active_ancestor = create(:tag, name: 'expand_active_ancestor')
+      TagImplication.create!(tag: child, parent_tag: deprecated_parent)
+      TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
+      TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_ancestor)
+
+      expanded = described_class.expand_parent_tags([child])
+
+      expect(expanded).to include(
+        child,
+        deprecated_parent,
+        deprecated_grandparent,
+        active_ancestor
+      )
+      expect(expanded.reject(&:deprecated?)).to contain_exactly(child, active_ancestor)
+    end
+
+    it 'terminates when implications contain a cycle' do
+      first = create(:tag, name: 'expand_cycle_first')
+      second = create(:tag, name: 'expand_cycle_second')
+      TagImplication.create!(tag: first, parent_tag: second)
+      TagImplication.create!(tag: second, parent_tag: first)
+
+      expect(described_class.expand_parent_tags([first])).to contain_exactly(first, second)
+    end
+  end
+
+  describe 'deprecated validation' do
+    it 'rejects deprecated nico tags' do
+      tag = build(
+        :tag,
+        name: 'nico:deprecated_validation',
+        category: :nico,
+        deprecated_at: Time.current
+      )
+
+      expect(tag).not_to be_valid
+      expect(tag.errors[:deprecated_at]).to include('ニコタグは廃止できません．')
+    end
+  end
+
   describe '.merge_tags!' do
     let!(:target_tag) { create(:tag, category: :general) }
     let!(:source_tag) { create(:tag, category: :general) }

backend/spec/requests/gekanator_learning_spec.rb

@@ -897,6 +897,37 @@ RSpec.describe 'Gekanator learning API', type: :request do
   end
 
   describe 'GET /gekanator/questions' do
+    it 'omits questions for deprecated tags' do
+      active_tag = Tag.create!(name: 'active_question_tag', category: :general)
+      deprecated_tag = Tag.create!(
+        name: 'deprecated_question_tag',
+        category: :general,
+        deprecated_at: Time.current
+      )
+
+      [active_tag, deprecated_tag].each do |question_tag|
+        GekanatorQuestion.create!(
+          text: "#{ question_tag.name }?",
+          kind: 'tag',
+          source: 'admin_curated',
+          status: 'accepted',
+          priority_weight: 1.0,
+          condition: {
+            type: 'tag',
+            key: "#{ question_tag.category }:#{ question_tag.name }"
+          },
+          created_by: admin
+        )
+      end
+
+      get '/gekanator/questions'
+
+      expect(response).to have_http_status(:ok)
+      question_ids = json.fetch('questions').map { |question| question.fetch('id') }
+      expect(question_ids).to include('tag:general:active_question_tag')
+      expect(question_ids).not_to include('tag:general:deprecated_question_tag')
+    end
+
     it 'returns accepted questions only and includes example_answers for post_similarity questions' do
       sign_in_as admin
 

backend/spec/requests/gekanator_posts_spec.rb

@@ -0,0 +1,33 @@
+require 'rails_helper'
+
+
+RSpec.describe 'Gekanator posts API', type: :request do
+  describe 'GET /gekanator/posts' do
+    it 'omits deprecated tags and returns the stored similarity cosine' do
+      active_tag = Tag.create!(name: 'active tag', category: :general)
+      deprecated_tag = Tag.create!(
+        name: 'deprecated tag',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      post_record = Post.create!(title: 'source', url: 'https://example.com/source')
+      target_post = Post.create!(title: 'target', url: 'https://example.com/target')
+
+      PostTag.create!(post: post_record, tag: active_tag)
+      PostTag.create!(post: post_record, tag: deprecated_tag)
+      PostTag.create!(post: target_post, tag: deprecated_tag)
+      PostSimilarity.create!(post: post_record, target_post:, cos: 0.375)
+
+      get '/gekanator/posts'
+
+      expect(response).to have_http_status(:ok)
+
+      post_json = json.fetch('posts').find { |post| post.fetch('id') == post_record.id }
+      expect(post_json.fetch('tags').map { |tag| tag.fetch('name') }).to eq(['active tag'])
+      expect(post_json.fetch('post_similarity_edges')).to contain_exactly(
+        'target_post_id' => target_post.id,
+        'cos' => 0.375
+      )
+    end
+  end
+end

backend/spec/requests/materials_spec.rb

@@ -1,7 +1,10 @@
 require 'rails_helper'
 
 RSpec.describe 'Materials API', type: :request do
+  include ActiveJob::TestHelper
+
   let!(:member_user) { create(:user, :member) }
+  let!(:admin_user)  { create(:user, :admin) }
   let!(:guest_user)  { create(:user) }
 
   def dummy_upload(filename: 'dummy.png', type: 'image/png', body: 'dummy')
@@ -13,22 +16,29 @@ RSpec.describe 'Materials API', type: :request do
   end
 
   def build_material(tag:, user:, parent: nil, file: dummy_upload, url: nil)
-    Material.new(tag:, parent:, url:, created_by_user: user, updated_by_user: user).tap do |material|
+    Material.new(tag:, parent:, url:,
+                 created_by_user: user,
+                 updated_by_user: user).tap do |material|
       material.file.attach(file) if file
       material.save!
     end
   end
 
   describe 'GET /materials' do
-    let!(:tag_a) { Tag.create!(tag_name: TagName.create!(name: 'material_index_a'), category: :material) }
-    let!(:tag_b) { Tag.create!(tag_name: TagName.create!(name: 'material_index_b'), category: :material) }
+    let!(:tag_a) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_index_a'), category: :material)
+    end
+    let!(:tag_b) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_index_b'), category: :material)
+    end
 
     let!(:material_a) do
       build_material(tag: tag_a, user: member_user, file: dummy_upload(filename: 'a.png'))
     end
 
     let!(:material_b) do
-      build_material(tag: tag_b, user: member_user, parent: material_a, file: dummy_upload(filename: 'b.png'))
+      build_material(tag: tag_b, user: member_user, parent: material_a,
+                     file: dummy_upload(filename: 'b.png'))
     end
 
     before do
@@ -97,7 +107,9 @@ RSpec.describe 'Materials API', type: :request do
   end
 
   describe 'GET /materials/:id' do
-    let!(:tag) { Tag.create!(tag_name: TagName.create!(name: 'material_show'), category: :material) }
+    let!(:tag) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_show'), category: :material)
+    end
     let!(:material) do
       build_material(tag:, user: member_user, file: dummy_upload(filename: 'show.png'))
     end
@@ -138,9 +150,22 @@ RSpec.describe 'Materials API', type: :request do
       end
     end
 
-    context 'when logged in' do
+    context 'when logged in but not member' do
       before { sign_in_as(guest_user) }
 
+      it 'returns 403' do
+        post '/materials', params: {
+          tag: 'material_create_guest_forbidden',
+          file: dummy_upload
+        }
+
+        expect(response).to have_http_status(:forbidden)
+      end
+    end
+
+    context 'when member' do
+      before { sign_in_as(member_user) }
+
       it 'returns 422 when tag is blank' do
         post '/materials', params: { tag: '   ', file: dummy_upload }
 
@@ -162,24 +187,49 @@ RSpec.describe 'Materials API', type: :request do
         expect do
           post '/materials', params: {
             tag: 'material_create_new',
-            file: dummy_upload(filename: 'created.png')
+            file: dummy_upload(filename: 'created.png'),
+            export_paths: { legacy_drive: '伊地知ニジカ/created.png' }
           }
         end.to change(Material, :count).by(1)
           .and change(Tag, :count).by(1)
           .and change(TagName, :count).by(1)
+          .and change(MaterialVersion, :count).by(1)
 
         expect(response).to have_http_status(:created)
 
         material = Material.order(:id).last
         expect(material.tag.name).to eq('material_create_new')
         expect(material.tag.category).to eq('material')
-        expect(material.created_by_user).to eq(guest_user)
-        expect(material.updated_by_user).to eq(guest_user)
+        expect(material.created_by_user).to eq(member_user)
+        expect(material.updated_by_user).to eq(member_user)
         expect(material.file.attached?).to be(true)
+        expect(material.version_no).to eq(1)
+        expect(material.material_versions.first.event_type).to eq('create')
+        expect(material.material_export_items.first.export_path).to eq('伊地知ニジカ/created.png')
+        expect(material.material_versions.first.export_paths_json).to eq(
+          'legacy_drive' => '伊地知ニジカ/created.png'
+        )
 
         expect(json['id']).to eq(material.id)
         expect(json.dig('tag', 'name')).to eq('material_create_new')
         expect(json['content_type']).to eq('image/png')
+        expect(json.dig('export_paths', 'legacy_drive')).to eq('伊地知ニジカ/created.png')
+      end
+
+      it 'snapshots attached file metadata and sha256' do
+        post '/materials', params: {
+          tag: 'material_create_file_version',
+          file: dummy_upload(filename: 'created.png', body: 'sha-body')
+        }
+
+        expect(response).to have_http_status(:created)
+
+        version = Material.order(:id).last.material_versions.first
+        expect(version.file_blob_id).to be_present
+        expect(version.file_filename).to eq('created.png')
+        expect(version.file_content_type).to eq('image/png')
+        expect(version.file_byte_size).to eq('sha-body'.bytesize)
+        expect(version.file_sha256).to eq(Digest::SHA256.hexdigest('sha-body'))
       end
 
       it 'returns 422 when the existing tag is not material/character' do
@@ -219,11 +269,33 @@ RSpec.describe 'Materials API', type: :request do
         expect(response).to have_http_status(:created)
         expect(json['url']).to eq('https://example.com/material-source')
       end
+
+      it 'rejects sha256-blocked file upload' do
+        sha256 = Digest::SHA256.hexdigest('blocked-body')
+        MaterialImportBlock.create!(match_kind: 'sha256',
+                                    sha256:,
+                                    reason: 'copyright_high_risk',
+                                    created_by_user: admin_user)
+
+        expect do
+          post '/materials', params: {
+            tag: 'material_blocked_create',
+            file: dummy_upload(filename: 'blocked.png', body: 'blocked-body')
+          }
+        end.not_to change(Material, :count)
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(json.fetch('errors')).to include(
+          'file' => ['抑止された素材です: copyright_high_risk']
+        )
+      end
     end
   end
 
   describe 'PUT /materials/:id' do
-    let!(:tag) { Tag.create!(tag_name: TagName.create!(name: 'material_update_old'), category: :material) }
+    let!(:tag) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_update_old'), category: :material)
+    end
     let!(:material) do
       build_material(tag:, user: member_user, file: dummy_upload(filename: 'old.png'))
     end
@@ -277,25 +349,26 @@ RSpec.describe 'Materials API', type: :request do
             'tag' => ['タグは必須です．'])
       end
 
-      it 'returns 422 when both file and url are blank' do
+      it 'keeps the existing file when file and url are omitted' do
         put "/materials/#{ material.id }", params: {
           tag: 'material_update_no_payload'
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
-        expect(json.fetch('errors')).to include(
-            'file' => ['ファイルまたは URL は必須です．'],
-            'url' => ['ファイルまたは URL は必須です．'])
+        expect(response).to have_http_status(:ok)
+        expect(material.reload.file.attached?).to be(true)
       end
 
       it 'updates tag, url, file, and updated_by_user' do
         old_blob_id = material.file.blob.id
 
-        put "/materials/#{ material.id }", params: {
-          tag: 'material_update_new',
-          url: 'https://example.com/updated-source',
-          file: dummy_upload(filename: 'updated.jpg', type: 'image/jpeg')
-        }
+        expect do
+          put "/materials/#{ material.id }", params: {
+            tag: 'material_update_new',
+            url: 'https://example.com/updated-source',
+            file: dummy_upload(filename: 'updated.jpg', type: 'image/jpeg'),
+            export_paths: { legacy_drive: '伊地知ニジカ/updated.jpg' }
+          }
+        end.to change(MaterialVersion, :count).by(2)
 
         expect(response).to have_http_status(:ok)
 
@@ -306,8 +379,15 @@ RSpec.describe 'Materials API', type: :request do
         expect(material.updated_by_user).to eq(member_user)
         expect(material.file.attached?).to be(true)
         expect(material.file.blob.id).not_to eq(old_blob_id)
+        expect(ActiveStorage::Blob.where(id: old_blob_id).exists?).to be(true)
         expect(material.file.blob.filename.to_s).to eq('updated.jpg')
         expect(material.file.blob.content_type).to eq('image/jpeg')
+        expect(material.version_no).to eq(2)
+        expect(material.material_versions.order(:version_no).last.event_type).to eq('update')
+        expect(material.material_export_items.first.export_path).to eq('伊地知ニジカ/updated.jpg')
+        expect(material.material_versions.order(:version_no).last.export_paths_json).to eq(
+          'legacy_drive' => '伊地知ニジカ/updated.jpg'
+        )
 
         expect(json['id']).to eq(material.id)
         expect(json['file']).to be_present
@@ -315,7 +395,7 @@ RSpec.describe 'Materials API', type: :request do
         expect(json.dig('tag', 'name')).to eq('material_update_new')
       end
 
-      it 'purges the existing file when file is omitted and url is provided' do
+      it 'detaches the existing file without purging blob when url replaces file' do
         old_blob_id = material.file.blob.id
 
         put "/materials/#{ material.id }", params: {
@@ -331,9 +411,7 @@ RSpec.describe 'Materials API', type: :request do
         expect(material.updated_by_user).to eq(member_user)
         expect(material.file.attached?).to be(false)
 
-        expect(
-          ActiveStorage::Blob.where(id: old_blob_id).exists?
-        ).to be(false)
+        expect(ActiveStorage::Blob.where(id: old_blob_id).exists?).to be(true)
 
         expect(json['id']).to eq(material.id)
         expect(json['file']).to be_nil
@@ -341,11 +419,190 @@ RSpec.describe 'Materials API', type: :request do
         expect(json.dig('tag', 'name')).to eq('material_update_remove_file')
         expect(json['url']).to eq('https://example.com/updated-source')
       end
+
+      it 'does not increase version for the same snapshot update' do
+        MaterialVersionRecorder.record!(material:, event_type: :create,
+                                        created_by_user: member_user)
+
+        expect do
+          put "/materials/#{ material.id }", params: {
+            tag: 'material_update_old'
+          }
+        end.not_to change(MaterialVersion, :count)
+
+        expect(response).to have_http_status(:ok)
+        expect(material.reload.version_no).to eq(1)
+      end
+
+      it 'records update version when only export_path changes' do
+        MaterialVersionRecorder.record!(material:, event_type: :create,
+                                        created_by_user: member_user)
+
+        expect do
+          put "/materials/#{ material.id }", params: {
+            tag: 'material_update_old',
+            export_paths: { legacy_drive: '素材/only-path.png' }
+          }
+        end.to change(MaterialVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+        expect(material.reload.material_export_items.first.export_path).to eq('素材/only-path.png')
+        expect(material.material_versions.order(:version_no).last.export_paths_json).to eq(
+          'legacy_drive' => '素材/only-path.png'
+        )
+      end
+
+      it 'removes export_path item when blank is submitted' do
+        MaterialExportItem.create!(material:, profile: 'legacy_drive',
+                                   export_path: '素材/remove.png',
+                                   created_by_user: member_user)
+        MaterialVersionRecorder.record!(material:, event_type: :create,
+                                        created_by_user: member_user)
+
+        expect do
+          put "/materials/#{ material.id }", params: {
+            tag: 'material_update_old',
+            export_paths: { legacy_drive: '' }
+          }
+        end.to change(MaterialExportItem, :count).by(-1)
+          .and change(MaterialVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+        expect(material.reload.material_export_items).to be_empty
+        expect(material.material_versions.order(:version_no).last.export_paths_json).to eq({})
+      end
+
+      it 'rejects sha256-blocked replacement file' do
+        sha256 = Digest::SHA256.hexdigest('blocked-update')
+        MaterialImportBlock.create!(match_kind: 'sha256',
+                                    sha256:,
+                                    reason: 'source_owner_request',
+                                    created_by_user: admin_user)
+
+        put "/materials/#{ material.id }", params: {
+          tag: 'material_update_old',
+          file: dummy_upload(filename: 'blocked.png', body: 'blocked-update')
+        }
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(material.reload.file.blob.filename.to_s).to eq('old.png')
+      end
+    end
+  end
+
+  describe 'GET /materials/download.zip' do
+    let!(:tag_a) { Tag.create!(tag_name: TagName.create!(name: 'zip_a'), category: :material) }
+    let!(:tag_b) { Tag.create!(tag_name: TagName.create!(name: 'zip_b'), category: :material) }
+    let!(:material_a) do
+      build_material(tag: tag_a, user: member_user,
+                     file: dummy_upload(filename: 'a.png', body: 'zip-a'))
+    end
+    let!(:material_b) do
+      build_material(tag: tag_b, user: member_user,
+                     file: dummy_upload(filename: 'b.png', body: 'zip-b'))
+    end
+
+    before do
+      MaterialExportItem.create!(material: material_a, profile: 'legacy_drive',
+                                 export_path: '素材/a.png',
+                                 created_by_user: member_user)
+      MaterialExportItem.create!(material: material_b, profile: 'legacy_drive',
+                                 export_path: '素材/b.png',
+                                 created_by_user: member_user)
+    end
+
+    it 'uses material_export_items.export_path as ZIP entry paths' do
+      get '/materials/download.zip', params: { profile: 'legacy_drive' }
+
+      expect(response).to have_http_status(:ok)
+      expect(response.media_type).to eq('application/zip')
+      expect(response.body.b).to include('素材/a.png'.b)
+      expect(response.body.b).to include('素材/b.png'.b)
+    end
+
+    it 'filters by tag_id' do
+      get '/materials/download.zip', params: { profile: 'legacy_drive', tag_id: tag_a.id }
+
+      expect(response).to have_http_status(:ok)
+      expect(response.body.b).to include('素材/a.png'.b)
+      expect(response.body.b).not_to include('素材/b.png'.b)
+    end
+
+    it 'does not include suppressed materials' do
+      material_b.update!(file_suppressed_at: Time.current,
+                         file_suppression_reason: 'copyright_high_risk')
+
+      get '/materials/download.zip', params: { profile: 'legacy_drive' }
+
+      expect(response).to have_http_status(:ok)
+      expect(response.body.b).to include('素材/a.png'.b)
+      expect(response.body.b).not_to include('素材/b.png'.b)
+    end
+  end
+
+  describe 'PATCH /materials/:id/suppress_file' do
+    let!(:tag) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_suppress'), category: :material)
+    end
+    let!(:material) do
+      build_material(tag:, user: member_user, file: dummy_upload(filename: 'suppress.png'))
+    end
+
+    it 'allows admin to suppress a file and records a suppress version' do
+      sign_in_as(admin_user)
+      MaterialVersionRecorder.record!(material:, event_type: :create,
+                                      created_by_user: member_user)
+
+      expect do
+        patch "/materials/#{ material.id }/suppress_file",
+              params: { reason: 'copyright_high_risk' }
+      end.to change(MaterialVersion, :count).by(1)
+
+      expect(response).to have_http_status(:ok)
+
+      material.reload
+      expect(material.file_suppressed_at).to be_present
+      expect(material.file_suppressed_by_user).to eq(admin_user)
+      expect(material.file_suppression_reason).to eq('copyright_high_risk')
+      expect(material.material_versions.order(:version_no).last.event_type).to eq('suppress')
+      expect(json['file']).to be_nil
+      expect(json['file_suppressed_at']).to be_present
+    end
+
+    it 'purges blob when purge=true is requested' do
+      sign_in_as(admin_user)
+      old_blob_id = material.file.blob.id
+      MaterialVersionRecorder.record!(material:, event_type: :create,
+                                      created_by_user: member_user)
+
+      expect do
+        patch "/materials/#{ material.id }/suppress_file",
+              params: { reason: 'copyright_takedown', purge: '1' }
+      end.to have_enqueued_job(ActiveStorage::PurgeJob)
+
+      expect(response).to have_http_status(:ok)
+
+      version = material.material_versions.order(:version_no).last
+      expect(version.event_type).to eq('suppress')
+      expect(version.file_blob_id).to eq(old_blob_id)
+      expect(version.file_filename).to eq('suppress.png')
+      expect(version.file_sha256).to be_present
+    end
+
+    it 'rejects member suppression' do
+      sign_in_as(member_user)
+
+      patch "/materials/#{ material.id }/suppress_file",
+            params: { reason: 'copyright_high_risk' }
+
+      expect(response).to have_http_status(:forbidden)
     end
   end
 
   describe 'DELETE /materials/:id' do
-    let!(:tag) { Tag.create!(tag_name: TagName.create!(name: 'material_destroy'), category: :material) }
+    let!(:tag) do
+      Tag.create!(tag_name: TagName.create!(name: 'material_destroy'), category: :material)
+    end
     let!(:material) do
       build_material(tag:, user: member_user, file: dummy_upload(filename: 'destroy.png'))
     end

backend/spec/requests/posts_spec.rb

@@ -517,6 +517,24 @@ RSpec.describe 'Posts API', type: :request do
         expect([true, false]).to include(json['viewed'])
       end
 
+      it 'omits deprecated tags' do
+        deprecated_tag = Tag.create!(
+          name: 'deprecated_post_tag',
+          category: :general,
+          deprecated_at: Time.current
+        )
+        PostTag.create!(post: post_record, tag: deprecated_tag)
+
+        request
+
+        expect(response).to have_http_status(:ok)
+        tag_names = json.fetch('tags').flat_map { |node|
+          [node.fetch('name')] + node.fetch('children').map { |child| child.fetch('name') }
+        }
+        expect(tag_names).to include('spec_tag')
+        expect(tag_names).not_to include('deprecated_post_tag')
+      end
+
       context 'when post has parent, child, and sibling posts' do
         let!(:parent_post) do
           create_parent_post!(
@@ -697,6 +715,58 @@ RSpec.describe 'Posts API', type: :request do
       expect(names).not_to include('manko')
     end
 
+    it 'rejects a deprecated tag specified directly' do
+      Tag.create!(
+        name: 'deprecated_direct_tag',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      sign_in_as(member)
+
+      post '/posts', params: post_write_params(
+        title: 'new post',
+        url: 'https://example.com/deprecated-direct-tag',
+        tags: 'deprecated_direct_tag',
+        thumbnail: dummy_upload
+      )
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(json.fetch('errors')).to include(
+        'tags' => ['廃止済みタグは付与できません．']
+      )
+    end
+
+    it 'expands through multiple deprecated parent tags and saves active ancestors' do
+      child = Tag.create!(name: 'active_child', category: :general)
+      deprecated_parent = Tag.create!(
+        name: 'deprecated_parent',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      deprecated_grandparent = Tag.create!(
+        name: 'deprecated_grandparent',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      active_grandparent = Tag.create!(name: 'active_grandparent', category: :general)
+      TagImplication.create!(tag: child, parent_tag: deprecated_parent)
+      TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
+      TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_grandparent)
+      sign_in_as(member)
+
+      post '/posts', params: post_write_params(
+        title: 'expanded post',
+        url: 'https://example.com/expanded-deprecated-parent',
+        tags: 'active_child',
+        thumbnail: dummy_upload
+      )
+
+      expect(response).to have_http_status(:created)
+      saved_names = Post.find(json.fetch('id')).tags.map(&:name)
+      expect(saved_names).to include('active_child', 'active_grandparent')
+      expect(saved_names).not_to include('deprecated_parent', 'deprecated_grandparent')
+    end
+
     context "when nico tag already exists in tags" do
       before do
         Tag.find_undiscard_or_create_by!(
@@ -930,6 +1000,26 @@ RSpec.describe 'Posts API', type: :request do
       expect(names).to include('spec_tag_2')
     end
 
+    it 'rejects a deprecated tag specified directly' do
+      Tag.create!(
+        name: 'deprecated_update_tag',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      sign_in_as(member)
+
+      put "/posts/#{ post_record.id }", params: post_update_params(
+        post_record,
+        title: 'updated title',
+        tags: 'deprecated_update_tag'
+      )
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(json.fetch('errors')).to include(
+        'tags' => ['廃止済みタグは付与できません．']
+      )
+    end
+
     context "when nico tag already exists in tags" do
       before do
         Tag.find_undiscard_or_create_by!(

backend/spec/requests/tag_versions_spec.rb

@@ -21,6 +21,7 @@ RSpec.describe 'TagVersions API', type: :request do
     event_type:,
     name:,
     category:,
+    deprecated_at: nil,
     aliases: [],
     parent_tags: [],
     created_by_user:,
@@ -33,6 +34,7 @@ RSpec.describe 'TagVersions API', type: :request do
             event_type: event_type,
             name: name,
             category: category,
+            deprecated_at: deprecated_at,
             aliases: Array(aliases).join(' '),
             parent_tag_ids: Array(parent_tags).map(&:id).join(' '),
             created_by_user: created_by_user,
@@ -65,6 +67,7 @@ RSpec.describe 'TagVersions API', type: :request do
       event_type: 'update',
       name: 'new_tag_name',
       category: 'meme',
+      deprecated_at: t_v2,
       aliases: ['alias_shared', 'alias_new'],
       parent_tags: [parent_shared, parent_new],
       created_by_user: member,
@@ -133,6 +136,10 @@ RSpec.describe 'TagVersions API', type: :request do
         'current' => 'meme',
         'prev' => 'general'
       )
+      expect(latest.fetch('deprecated_at')).to eq(
+        'current' => t_v2.iso8601,
+        'prev' => nil
+      )
       expect(latest.fetch('aliases')).to include(
         { 'name' => 'alias_shared', 'type' => 'context' },
         { 'name' => 'alias_new', 'type' => 'added' },
@@ -178,6 +185,10 @@ RSpec.describe 'TagVersions API', type: :request do
         'current' => 'general',
         'prev' => nil
       )
+      expect(first.fetch('deprecated_at')).to eq(
+        'current' => nil,
+        'prev' => nil
+      )
       expect(first.fetch('aliases')).to include(
         { 'name' => 'alias_shared', 'type' => 'added' },
         { 'name' => 'alias_old', 'type' => 'added' }

backend/spec/requests/tag_wiki_history_integrity_spec.rb

@@ -89,6 +89,7 @@ RSpec.describe 'Tag and wiki history integrity', type: :request do
           category: 'general',
           aliases: '',
           parent_tags: '',
+          deprecated: '0',
         }
       }
           .to change(TagVersion, :count).by(2)
@@ -123,6 +124,7 @@ RSpec.describe 'Tag and wiki history integrity', type: :request do
           category: 'meme',
           aliases: '',
           parent_tags: '',
+          deprecated: '0',
         }
       }
           .to change(TagVersion, :count).by(2)
@@ -149,6 +151,7 @@ RSpec.describe 'Tag and wiki history integrity', type: :request do
           category: 'general',
           aliases: 'put_tag_alias_only_alias',
           parent_tags: '',
+          deprecated: '0',
         }
       }
           .to change(TagVersion, :count).by(2)

backend/spec/requests/tags_spec.rb

@@ -76,6 +76,27 @@ RSpec.describe 'Tags API', type: :request do
       expect(response_tags.first['id']).to eq(meme.id)
     end
 
+    it 'filters tags by deprecated state' do
+      deprecated_tag = Tag.create!(
+        name: 'deprecated_filter',
+        category: :general,
+        deprecated_at: 1.day.from_now
+      )
+      active_tag = Tag.create!(name: 'active_filter', category: :general)
+
+      get '/tags', params: { name: '_filter', deprecated: '1' }
+
+      expect(response).to have_http_status(:ok)
+      expect(response_names).to include(deprecated_tag.name)
+      expect(response_names).not_to include(active_tag.name)
+
+      get '/tags', params: { name: '_filter', deprecated: '0' }
+
+      expect(response).to have_http_status(:ok)
+      expect(response_names).to include(active_tag.name)
+      expect(response_names).not_to include(deprecated_tag.name)
+    end
+
     it 'filters tags by post_count range' do
       low = Tag.create!(tag_name: TagName.create!(name: 'pc_low'), category: :general)
       mid = Tag.create!(tag_name: TagName.create!(name: 'pc_mid'), category: :general)
@@ -301,6 +322,21 @@ RSpec.describe 'Tags API', type: :request do
       expect(t['matched_alias']).to eq('unko')
       expect(json.map { |x| x['name'] }).not_to include('unknown')
     end
+
+    it 'omits deprecated tags' do
+      deprecated_tag = Tag.create!(
+        name: 'spec_deprecated',
+        category: :general,
+        deprecated_at: Time.current
+      )
+      deprecated_tag.update_columns(post_count: 1)
+
+      get '/tags/autocomplete', params: { q: 'spec_', present: '0' }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.map { |item| item.fetch('name') }).to include('spec_tag')
+      expect(json.map { |item| item.fetch('name') }).not_to include('spec_deprecated')
+    end
   end
 
   describe 'GET /tags/name/:name' do
@@ -437,6 +473,32 @@ RSpec.describe 'Tags API', type: :request do
         expect(versions.second.created_by_user_id).to eq(member_user.id)
       end
 
+      it 'updates deprecated state and records it in tag versions' do
+        expect {
+          patch "/tags/#{ tag.id }", params: { deprecated: '1' }
+        }.to change(TagVersion, :count).by(2)
+
+        expect(response).to have_http_status(:ok)
+        expect(tag.reload.deprecated_at).to be_present
+
+        versions = tag.tag_versions.order(:version_no)
+        expect(versions.first.deprecated_at).to be_nil
+        expect(versions.second.deprecated_at).to eq(tag.deprecated_at)
+        expect(json.fetch('deprecated_at')).to be_present
+      end
+
+      it 'rejects deprecating a nico tag' do
+        nico_tag = Tag.create!(name: 'nico:deprecated_update', category: :nico)
+
+        patch "/tags/#{ nico_tag.id }", params: { deprecated: '1' }
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(nico_tag.reload.deprecated_at).to be_nil
+        expect(json.fetch('errors')).to include(
+          'deprecated' => ['ニコタグは廃止できません．']
+        )
+      end
+
       it 'returns 422 when changing normal tag category to nico' do
         expect {
           patch "/tags/#{tag.id}", params: { category: 'nico' }
@@ -585,6 +647,111 @@ RSpec.describe 'Tags API', type: :request do
       expect(row['has_children']).to eq(true)
       expect(row['children']).to eq([])
     end
+
+    it 'passes through deprecated tags when finding children' do
+      deprecated_middle = Tag.create!(
+        name: 'depth_deprecated_middle',
+        category: :character,
+        deprecated_at: Time.current
+      )
+      visible_descendant = Tag.create!(
+        name: 'depth_visible_descendant',
+        category: :material
+      )
+      TagImplication.create!(parent_tag: root_material, tag: deprecated_middle)
+      TagImplication.create!(parent_tag: deprecated_middle, tag: visible_descendant)
+
+      get '/tags/with-depth', params: { parent: root_material.id }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.map { |item| item.fetch('name') }).to eq(['depth_visible_descendant'])
+      expect(json.map { |item| item.fetch('name') }).not_to include('depth_deprecated_middle')
+    end
+
+    it 'passes through multiple deprecated tags for roots and has_children' do
+      active_child = Tag.create!(
+        name: 'depth_active_child_below_deprecated',
+        category: :character
+      )
+      deprecated_parent = Tag.create!(
+        name: 'depth_deprecated_parent',
+        category: :character,
+        deprecated_at: Time.current
+      )
+      deprecated_grandparent = Tag.create!(
+        name: 'depth_deprecated_grandparent',
+        category: :material,
+        deprecated_at: Time.current
+      )
+      active_ancestor = Tag.create!(
+        name: 'depth_active_ancestor',
+        category: :meme
+      )
+      TagImplication.create!(tag: active_child, parent_tag: deprecated_parent)
+      TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
+      TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_ancestor)
+
+      get '/tags/with-depth'
+
+      root_names = json.map { |item| item.fetch('name') }
+      expect(root_names).to include('depth_active_ancestor')
+      expect(root_names).not_to include('depth_active_child_below_deprecated')
+      ancestor_json = json.find { |item| item.fetch('id') == active_ancestor.id }
+      expect(ancestor_json.fetch('has_children')).to eq(true)
+
+      get '/tags/with-depth', params: { parent: active_ancestor.id }
+
+      expect(json.map { |item| item.fetch('name') }).to include(
+        'depth_active_child_below_deprecated'
+      )
+      expect(json.map { |item| item.fetch('name') }).not_to include(
+        'depth_deprecated_parent',
+        'depth_deprecated_grandparent'
+      )
+    end
+
+    it 'treats an active tag with only deprecated ancestors as a root' do
+      active_child = Tag.create!(
+        name: 'depth_root_below_deprecated',
+        category: :character
+      )
+      deprecated_parent = Tag.create!(
+        name: 'depth_root_deprecated_parent',
+        category: :material,
+        deprecated_at: Time.current
+      )
+      TagImplication.create!(tag: active_child, parent_tag: deprecated_parent)
+
+      get '/tags/with-depth'
+
+      expect(json.map { |item| item.fetch('name') }).to include(
+        'depth_root_below_deprecated'
+      )
+      expect(json.map { |item| item.fetch('name') }).not_to include(
+        'depth_root_deprecated_parent'
+      )
+    end
+
+    it 'terminates when deprecated implications contain a cycle' do
+      first = Tag.create!(
+        name: 'depth_cycle_first',
+        category: :character,
+        deprecated_at: Time.current
+      )
+      second = Tag.create!(
+        name: 'depth_cycle_second',
+        category: :material,
+        deprecated_at: Time.current
+      )
+      TagImplication.create!(tag: first, parent_tag: root_material)
+      TagImplication.create!(tag: second, parent_tag: first)
+      TagImplication.create!(tag: first, parent_tag: second)
+
+      get '/tags/with-depth', params: { parent: root_material.id }
+
+      expect(response).to have_http_status(:ok)
+      expect(json).to eq([])
+    end
   end
 
   describe 'GET /tags/name/:name/materials' do
@@ -732,6 +899,20 @@ RSpec.describe 'Tags API', type: :request do
         expect(tag.category).to eq('general')
       end
 
+      it 'deprecated がなければ 422 を返す' do
+        put "/tags/#{ tag.id }", params: {
+          name: 'new',
+          category: 'general',
+          aliases: '',
+          parent_tags: '',
+        }
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(json.fetch('errors')).to include(
+          'deprecated' => ['廃止状態は必須です．']
+        )
+      end
+
       it 'name, category, aliases, parent tags をまとめて更新できる' do
         old_parent = Tag.create!(
           tag_name: TagName.create!(name: 'put_old_parent'),
@@ -749,6 +930,7 @@ RSpec.describe 'Tags API', type: :request do
           category: 'meme',
           aliases: 'put_alias_a put_alias_b put_alias_a',
           parent_tags: 'put_kept_parent put_new_parent',
+          deprecated: '0',
         }
 
         expect(response).to have_http_status(:ok)
@@ -793,6 +975,7 @@ RSpec.describe 'Tags API', type: :request do
           category: 'general',
           aliases: 'spec_tag put_alias_self_test',
           parent_tags: '',
+          deprecated: '0',
         }
 
         expect(response).to have_http_status(:ok)
@@ -810,6 +993,7 @@ RSpec.describe 'Tags API', type: :request do
           category: 'general',
           aliases: 'unko',
           parent_tags: 'spec_tag',
+          deprecated: '0',
         }
 
         expect(response).to have_http_status(:ok)
@@ -825,6 +1009,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'meta',
             aliases: '',
             parent_tags: '',
+            deprecated: '0',
           }
         }.to change(TagVersion, :count).by(2)
 
@@ -860,6 +1045,7 @@ RSpec.describe 'Tags API', type: :request do
           category: 'general',
           aliases: 'unko',
           parent_tags: new_parent.name,
+          deprecated: '0',
         }
 
         expect(response).to have_http_status(:ok)
@@ -875,6 +1061,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'nico',
             aliases: '',
             parent_tags: '',
+            deprecated: '0',
           }
         }.not_to change(TagVersion, :count)
 
@@ -896,6 +1083,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'nico',
             aliases: '',
             parent_tags: '',
+            deprecated: '0',
           }
         }.not_to change(NicoTagVersion, :count)
 
@@ -916,6 +1104,7 @@ RSpec.describe 'Tags API', type: :request do
             category: old_category,
             aliases: '',
             parent_tags: '',
+            deprecated: '0',
           }
         }.not_to change(TagVersion, :count)
 
@@ -946,6 +1135,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'meme',
             aliases: 'unko',
             parent_tags: '',
+            deprecated: '0',
           }
         }
             .to change(TagVersion, :count).by(2)
@@ -981,6 +1171,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'general',
             aliases: 'unko put_stolen_alias',
             parent_tags: '',
+            deprecated: '0',
           }
         }
             .to change { tag.reload.tag_versions.count }.by(2)
@@ -1015,6 +1206,7 @@ RSpec.describe 'Tags API', type: :request do
           category: 'general',
           aliases: 'unko',
           parent_tags: child.name,
+          deprecated: '0',
         }
 
         expect(response).to have_http_status(:unprocessable_entity)
@@ -1036,6 +1228,7 @@ RSpec.describe 'Tags API', type: :request do
             category: 'general',
             aliases: 'unko',
             parent_tags: '',
+            deprecated: '0',
           }
         }
             .to change(TagVersion, :count).by(2)

backend/spec/requests/wiki_spec.rb

@@ -18,6 +18,13 @@ RSpec.describe 'Wiki API', type: :request do
         created_by_user: user,
         message: 'init')
   end
+  let!(:tag) do
+    Tag.create!(
+      tag_name: tn,
+      category: :general,
+      deprecated_at: Time.zone.local(2026, 6, 1)
+    )
+  end
 
   describe 'GET /wiki' do
     it 'returns wiki pages with title' do
@@ -30,6 +37,8 @@ RSpec.describe 'Wiki API', type: :request do
 
       expect(json[0]).to have_key('title')
       expect(json.map { |p| p['title'] }).to include('spec_wiki_title')
+      wiki_json = json.find { |item| item.fetch('id') == page.id }
+      expect(wiki_json.fetch('deprecated_at')).to eq(tag.deprecated_at.iso8601(3))
     end
   end
 
@@ -48,7 +57,8 @@ RSpec.describe 'Wiki API', type: :request do
 
         expect(json).to include(
             'id' => page.id,
-            'title' => 'spec_wiki_title')
+            'title' => 'spec_wiki_title',
+            'deprecated_at' => tag.deprecated_at.iso8601(3))
       end
     end
 
@@ -409,7 +419,11 @@ RSpec.describe 'Wiki API', type: :request do
         'kind' => 'content',
         'message' => 'r2'
       )
-      expect(top['wiki_page']).to include('id' => page.id, 'title' => 'spec_wiki_title')
+      expect(top['wiki_page']).to include(
+        'id' => page.id,
+        'title' => 'spec_wiki_title',
+        'deprecated_at' => tag.deprecated_at.iso8601(3)
+      )
       expect(top['user']).to include('id' => user.id, 'name' => user.name)
       expect(top).to have_key('timestamp')
 
@@ -479,6 +493,7 @@ RSpec.describe 'Wiki API', type: :request do
       expect(json).to include(
         'wiki_page_id' => page.id,
         'title' => 'spec_wiki_title',
+        'deprecated_at' => tag.deprecated_at.iso8601(3),
         'older_revision_id' => rev_a.id,
         'newer_revision_id' => rev_b.id
       )

backend/spec/tasks/post_similarity_calc_spec.rb

@@ -4,11 +4,12 @@ require 'rails_helper'
 RSpec.describe 'post_similarity:calc' do
   include RakeTaskHelper
 
-  it 'calls Similarity::Calc with Post and :tags' do
+  it 'calculates similarities from active tags only' do
     # 必要最低限のデータ
     t1 = Tag.create!(name: "t1")
     t2 = Tag.create!(name: "t2")
     t3 = Tag.create!(name: "t3")
+    deprecated_tag = Tag.create!(name: 'deprecated', deprecated_at: Time.current)
 
     p1 = Post.create!(url: "https://example.com/1")
     p2 = Post.create!(url: "https://example.com/2")
@@ -22,6 +23,8 @@ RSpec.describe 'post_similarity:calc' do
     PostTag.create!(post: p2, tag: t3)
 
     PostTag.create!(post: p3, tag: t3)
+    PostTag.create!(post: p1, tag: deprecated_tag)
+    PostTag.create!(post: p2, tag: deprecated_tag)
 
     expect { run_rake_task("post_similarity:calc") }
       .to change { PostSimilarity.count }.from(0)
@@ -29,6 +32,6 @@ RSpec.describe 'post_similarity:calc' do
     ps = PostSimilarity.find_by!(post_id: p1.id, target_post_id: p2.id)
     ps_rev = PostSimilarity.find_by!(post_id: p2.id, target_post_id: p1.id)
     expect(ps_rev.cos).to eq(ps.cos)
+    expect(ps.cos).to be_within(0.0001).of(0.5)
   end
 end
-

backend/spec/tasks/tag_similarity_calc_spec.rb

@@ -4,11 +4,12 @@ require 'rails_helper'
 RSpec.describe 'tag_similarity:calc' do
   include RakeTaskHelper
 
-  it 'calls Similarity::Calc with Tag and :posts' do
+  it 'calculates similarities for active tags only' do
     # 必要最低限のデータ
     t1 = Tag.create!(name: "t1")
     t2 = Tag.create!(name: "t2")
     t3 = Tag.create!(name: "t3")
+    deprecated_tag = Tag.create!(name: 'deprecated', deprecated_at: Time.current)
 
     p1 = Post.create!(url: "https://example.com/1")
     p2 = Post.create!(url: "https://example.com/2")
@@ -22,6 +23,7 @@ RSpec.describe 'tag_similarity:calc' do
     PostTag.create!(post: p2, tag: t3)
 
     PostTag.create!(post: p3, tag: t3)
+    PostTag.create!(post: p1, tag: deprecated_tag)
 
     expect { run_rake_task("tag_similarity:calc") }
       .to change { TagSimilarity.count }.from(0)
@@ -29,6 +31,7 @@ RSpec.describe 'tag_similarity:calc' do
     ps = TagSimilarity.find_by!(tag_id: t1.id, target_tag_id: t2.id)
     ps_rev = TagSimilarity.find_by!(tag_id: t2.id, target_tag_id: t1.id)
     expect(ps_rev.cos).to eq(ps.cos)
+    expect(TagSimilarity.where(tag_id: deprecated_tag.id)).to be_empty
+    expect(TagSimilarity.where(target_tag_id: deprecated_tag.id)).to be_empty
   end
 end
-

frontend/src/App.tsx

@@ -69,7 +69,7 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/materials" element={<MaterialBasePage/>}>
 	    <Route index element={<MaterialListPage/>}/>
 	    <Route path="new" element={<MaterialNewPage/>}/>
-	    <Route path=":id" element ={<MaterialDetailPage/>}/>
+	    <Route path=":id" element ={<MaterialDetailPage user={user}/>}/>
 	  </Route>
 	  {/* <Route path="/materials/search" element={<MaterialSearchPage/>}/> */}
 	  <Route path="/wiki" element={<WikiSearchPage/>}/>

frontend/src/components/TagLink.test.tsx

@@ -18,6 +18,21 @@ describe ('TagLink', () => {
     expect (screen.getByText ('4')).toBeInTheDocument ()
   })
 
+  it ('does not append deprecated state to the rendered tag name', () => {
+    renderWithProviders (
+        <TagLink
+            tag={buildTag ({
+                name:         '旧タグ',
+                deprecatedAt: '2026-06-01T00:00:00.000Z',
+            })}
+            withWiki={false}
+            withCount={false}/>,
+    )
+
+    expect (screen.getByRole ('link', { name: '旧タグ' })).toBeInTheDocument ()
+    expect (screen.queryByText ('（廃止）')).not.toBeInTheDocument ()
+  })
+
   it ('links wiki markers to the correct detail route', () => {
     renderWithProviders (
         <TagLink tag={buildTag ({ hasWiki: true, name: 'a/b' })}/>,

frontend/src/components/TagLink.tsx

@@ -128,4 +128,4 @@ const TagLink: FC<Props> = ({ tag,
       </>)
 }
 
-export default TagLink
+export default TagLink

frontend/src/lib/gekanator.test.ts

@@ -1,9 +1,11 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
-import { apiPost } from '@/lib/api'
+import { apiGet, apiPost } from '@/lib/api'
 import {
   buildGekanatorQuestions,
   expectedAnswerForQuestion,
+  fetchGekanatorPosts,
+  fetchGekanatorQuestions,
   learnedSemanticSideForPost,
   questionIdForCondition,
   restoreGekanatorQuestion,
@@ -24,6 +26,7 @@ vi.mock('@/lib/api', () => ({
 }))
 
 const mockedApiPost = vi.mocked(apiPost)
+const mockedApiGet = vi.mocked(apiGet)
 
 const post = (overrides: Partial<Post> = {}): Post => ({
   id: 1,
@@ -43,6 +46,24 @@ const post = (overrides: Partial<Post> = {}): Post => ({
   ...overrides,
 })
 
+describe('Gekanator API functions', () => {
+  it('returns posts from the Gekanator posts endpoint', async () => {
+    const posts = [post()]
+    mockedApiGet.mockResolvedValueOnce({ posts })
+
+    await expect(fetchGekanatorPosts()).resolves.toEqual(posts)
+    expect(mockedApiGet).toHaveBeenCalledWith('/gekanator/posts')
+  })
+
+  it('returns questions from the Gekanator questions endpoint', async () => {
+    const questions: StoredGekanatorQuestion[] = []
+    mockedApiGet.mockResolvedValueOnce({ questions })
+
+    await expect(fetchGekanatorQuestions()).resolves.toEqual(questions)
+    expect(mockedApiGet).toHaveBeenCalledWith('/gekanator/questions')
+  })
+})
+
 describe('expectedAnswerForQuestion', () => {
   it('returns a direct example answer when present', () => {
     const question: StoredGekanatorQuestion = {
@@ -126,6 +147,7 @@ describe('expectedAnswerForQuestion', () => {
               postCount: 1,
               createdAt: '2026-06-10T00:00:00.000Z',
               updatedAt: '2026-06-10T00:00:00.000Z',
+              deprecatedAt: null,
               hasWiki: false,
               hasDeerjikists: false,
               materialId: null,

frontend/src/lib/prefetchers.ts

@@ -17,6 +17,10 @@ const mWiki = match<{ title: string }> ('/wiki/:title')
 const mTag = match<{ id: string }> ('/tags/:id')
 
 
+const boolFromQuery = (value: string | null): boolean =>
+    ['1', 'true', 'on', 'yes', ''].includes ((value ?? '').toLowerCase ())
+
+
 const prefetchWikiPagesIndex: Prefetcher = async (qc, url) => {
   const title = url.searchParams.get ('title') ?? ''
 
@@ -156,13 +160,16 @@ const prefetchTagsIndex: Prefetcher = async (qc, url) => {
   const createdTo = url.searchParams.get ('created_to') ?? ''
   const updatedFrom = url.searchParams.get ('updated_from') ?? ''
   const updatedTo = url.searchParams.get ('updated_to') ?? ''
+  const deprecated = url.searchParams.has ('deprecated')
+      ? boolFromQuery (url.searchParams.get ('deprecated'))
+      : null
   const page = Number (url.searchParams.get ('page') || 1)
   const limit = Number (url.searchParams.get ('limit') || 20)
   const order = (url.searchParams.get ('order') ?? 'post_count:desc') as FetchTagsOrder
 
   const keys = {
       post, name, category, postCountGTE, postCountLTE, createdFrom, createdTo,
-      updatedFrom, updatedTo, page, limit, order }
+      updatedFrom, updatedTo, deprecated, page, limit, order }
 
   await qc.prefetchQuery ({
       queryKey: tagsKeys.index (keys),

frontend/src/lib/tags.test.ts

@@ -20,6 +20,7 @@ const baseParams: FetchTagsParams = {
   createdTo:    '',
   updatedFrom:  '',
   updatedTo:    '',
+  deprecated:   null,
   page:         1,
   limit:        30,
   order:        'updated_at:desc',
@@ -57,6 +58,20 @@ describe ('tags API functions', () => {
     )
   })
 
+  it.each ([
+    [true, '1'],
+    [false, '0'],
+  ] as const) ('maps deprecated=%s to %s', async (deprecated, expected) => {
+    api.apiGet.mockResolvedValueOnce ({ tags: [], count: 0 })
+
+    await fetchTags ({ ...baseParams, deprecated })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/tags',
+        { params: expect.objectContaining ({ deprecated: expected }) },
+    )
+  })
+
   it ('returns null when tag fetches fail', async () => {
     api.apiGet.mockRejectedValueOnce (new Error ('missing'))
     api.apiGet.mockRejectedValueOnce (new Error ('missing'))

frontend/src/lib/tags.ts

@@ -10,7 +10,8 @@ import type { Deerjikist,
 
 export const fetchTags = async (
     { post, name, category, postCountGTE, postCountLTE, createdFrom, createdTo,
-      updatedFrom, updatedTo, page, limit, order }: FetchTagsParams,
+      updatedFrom, updatedTo, deprecated,
+      page, limit, order }: FetchTagsParams,
 ): Promise<{ tags:  Tag[]
 	     count: number }> =>
     await apiGet ('/tags', { params: {
@@ -23,6 +24,7 @@ export const fetchTags = async (
 	...(createdTo && { created_to: createdTo }),
 	...(updatedFrom && { updated_from: updatedFrom }),
 	...(updatedTo && { updated_to: updatedTo }),
+	...(deprecated != null && { deprecated: deprecated ? '1' : '0' }),
 	...(page && { page }),
 	...(limit && { limit }),
 	...(order && { order }) } })
@@ -64,7 +66,6 @@ export const fetchTagByName = async (name: string): Promise<Tag | null> => {
   }
 }
 
-
 export const fetchTagChanges = async (
     { id, page, limit }: {
 	id?:    string

frontend/src/pages/materials/MaterialDetailPage.test.tsx

@@ -8,6 +8,7 @@ import { renderWithProviders } from '@/test/render'
 
 const api = vi.hoisted (() => ({
   apiGet: vi.fn (),
+  apiPatch: vi.fn (),
   apiPut: vi.fn (),
 }))
 
@@ -26,7 +27,7 @@ vi.mock ('@/components/ui/use-toast', () => toastApi)
 const renderPage = () =>
   renderWithProviders (
       <Routes>
-        <Route path="/materials/:id" element={<MaterialDetailPage/>}/>
+        <Route path="/materials/:id" element={<MaterialDetailPage user={null}/>}/>
       </Routes>,
       { route: '/materials/8' },
   )
@@ -73,6 +74,7 @@ describe ('MaterialDetailPage', () => {
     const textboxes = screen.getAllByRole ('textbox')
     fireEvent.change (textboxes[0], { target: { value: 'new' } })
     fireEvent.change (textboxes[1], { target: { value: 'https://example.com/ref' } })
+    fireEvent.change (textboxes[2], { target: { value: '素材/new.png' } })
     fireEvent.click (screen.getByRole ('button', { name: '更新' }))
 
     await waitFor (() => {
@@ -81,6 +83,7 @@ describe ('MaterialDetailPage', () => {
     const formData = api.apiPut.mock.calls[0]?.[1] as FormData
     expect (formData.get ('tag')).toBe ('new')
     expect (formData.get ('url')).toBe ('https://example.com/ref')
+    expect (formData.get ('export_paths[legacy_drive]')).toBe ('素材/new.png')
     expect (toastApi.toast).toHaveBeenCalledWith ({ title: '更新成功!' })
   })
 })

frontend/src/pages/materials/MaterialDetailPage.tsx

@@ -13,22 +13,23 @@ import MainArea from '@/components/layout/MainArea'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
-import { apiGet, apiPut } from '@/lib/api'
+import { apiGet, apiPatch, apiPut } from '@/lib/api'
 import { inputClass } from '@/lib/utils'
 import { useValidationErrors } from '@/lib/useValidationErrors'
 
 import type { FC } from 'react'
 
-import type { Material, Tag } from '@/types'
+import type { Material, Tag, User } from '@/types'
 
 type MaterialWithTag = Material & { tag: Tag }
 
-type MaterialFormField = 'tag' | 'file' | 'url'
+type MaterialFormField = 'tag' | 'file' | 'url' | 'exportPaths'
 
 
-const MaterialDetailPage: FC = () => {
+const MaterialDetailPage: FC<{ user: User | null }> = ({ user }) => {
   const { id } = useParams ()
 
+  const [exportPath, setExportPath] = useState ('')
   const [file, setFile] = useState<File | null> (null)
   const [filePreview, setFilePreview] = useState ('')
   const [loading, setLoading] = useState (false)
@@ -49,6 +50,7 @@ const MaterialDetailPage: FC = () => {
       formData.append ('file', file)
     if (url.trim ())
       formData.append ('url', url)
+    formData.append ('export_paths[legacy_drive]', exportPath)
 
     try
     {
@@ -68,6 +70,30 @@ const MaterialDetailPage: FC = () => {
     }
   }
 
+  const handleSuppress = async () => {
+    const reason = window.prompt ('抑止理由を入力してください。')
+    if (reason == null || reason.trim () === '')
+      return
+    if (!window.confirm ('素材ファイルを抑止します。表示と ZIP export から除外されます。'))
+      return
+
+    try
+    {
+      const data = await apiPatch<Material> (
+	  `/materials/${ id }/suppress_file`,
+	  { reason },
+      )
+      setMaterial (data)
+      setFile (null)
+      setFilePreview ('')
+      toast ({ title: '抑止しました' })
+    }
+    catch
+    {
+      toast ({ title: '抑止に失敗しました' })
+    }
+  }
+
   useEffect (() => {
     if (!(id))
       return
@@ -82,11 +108,10 @@ const MaterialDetailPage: FC = () => {
 	if (data.file && data.contentType)
 	  {
 	    setFilePreview (data.file)
-	    setFile (new File ([await (await fetch (data.file)).blob ()],
-			       data.file,
-			       { type: data.contentType }))
+	    setFile (null)
 	  }
 	setURL (data.url ?? '')
+	setExportPath (data.exportPaths.legacyDrive ?? '')
       }
       finally
       {
@@ -111,7 +136,14 @@ const MaterialDetailPage: FC = () => {
 		    withCount={false}/>
 	      </PageTitle>
 
-	      {(material.file && material.contentType) && (
+	      {material.fileSuppressedAt && (
+		  <div className="mb-4 rounded border border-red-300 bg-red-50 p-3 text-red-700">
+		    <span>素材ファイルは抑止済みです。</span>
+		    {material.fileSuppressionReason && (
+			<span> 理由: {material.fileSuppressionReason}</span>)}
+		  </div>)}
+
+	      {(!material.fileSuppressedAt && material.file && material.contentType) && (
 		  (/image\/.*/.test (material.contentType) && (
 		      <img src={material.file} alt={material.tag.name || undefined}/>))
 		  || (/video\/.*/.test (material.contentType) && (
@@ -189,13 +221,36 @@ const MaterialDetailPage: FC = () => {
 			      className={inputClass (invalid)}/>)}
 		    </FormField>
 
+		    <FormField
+			label="ZIP 出力パス"
+			messages={fieldErrors.exportPaths}>
+		      {({ describedBy, invalid }) => (
+			  <input
+			      type="text"
+			      value={exportPath}
+			      onChange={e => setExportPath (e.target.value)}
+			      placeholder="伊地知ニジカ/表情/泣き.png"
+			      aria-describedby={describedBy}
+			      aria-invalid={invalid}
+			      className={inputClass (invalid)}/>)}
+		    </FormField>
+
 		    {/* 送信 */}
-		    <Button
-			onClick={handleSubmit}
-			className="px-4 py-2 bg-blue-600 text-white rounded disabled:bg-gray-400"
-			disabled={sending}>
-		      更新
-		    </Button>
+		    <div className="flex flex-wrap gap-2">
+		      <Button
+			  onClick={handleSubmit}
+			  className="px-4 py-2 bg-blue-600 text-white rounded disabled:bg-gray-400"
+			  disabled={sending}>
+			更新
+		      </Button>
+		      {user?.role === 'admin' && !material.fileSuppressedAt && (
+			  <Button
+			      type="button"
+			      variant="destructive"
+			      onClick={handleSuppress}>
+			    ファイルを抑止
+			  </Button>)}
+		    </div>
 		  </div>
 		</Tab>
 	      </TabGroup>

frontend/src/pages/materials/MaterialListPage.tsx

@@ -9,7 +9,7 @@ import PageTitle from '@/components/common/PageTitle'
 import SectionTitle from '@/components/common/SectionTitle'
 import SubsectionTitle from '@/components/common/SubsectionTitle'
 import MainArea from '@/components/layout/MainArea'
-import { SITE_TITLE } from '@/config'
+import { API_BASE_URL, SITE_TITLE } from '@/config'
 import { apiGet } from '@/lib/api'
 
 import type { FC } from 'react'
@@ -30,10 +30,15 @@ const MaterialCard = ({ tag }: { tag: TagWithMaterial }) => {
 	  to={`/materials/${ tag.material.id }`}
 	  className="block w-40 h-40">
 	<div
-	    className="w-full h-full overflow-hidden rounded-xl shadow
-		       text-center content-center text-4xl"
+	    className={`w-full h-full overflow-hidden rounded-xl shadow
+			text-center content-center text-4xl ${
+			tag.material.fileSuppressedAt
+			? 'border-2 border-red-300 bg-red-50 text-base text-red-700'
+			: '' }`}
 	    style={{ fontFamily: 'Nikumaru' }}>
-	  {(tag.material.contentType && /image\/.*/.test (tag.material.contentType))
+	  {tag.material.fileSuppressedAt
+	   ? <span>抑止済み</span>
+	   : (tag.material.contentType && /image\/.*/.test (tag.material.contentType))
 	   ? <img src={tag.material.file || undefined}/>
 	   : <span>照会</span>}
 	</div>
@@ -108,7 +113,7 @@ const MaterialListPage: FC = () => {
 
 		  <MaterialCard tag={tag}/>
 
-		  <div className="ml-2">
+		  <div className="ml-2 overflow-x-auto pb-2">
 		    {tag.children.map (c2 => (
 			<Fragment key={c2.id}>
 			  <SectionTitle>
@@ -159,7 +164,11 @@ const MaterialListPage: FC = () => {
 		  <p>もしくは……</p>
 		  <ul>
 		    <li><PrefetchLink to="/materials/new">素材を新規追加する</PrefetchLink></li>
-		    {/* <li><a href="#">すべての素材をダウンロードする</a></li> */}
+		    <li>
+		      <a href={`${ API_BASE_URL }/materials/download.zip?profile=legacy_drive`}>
+			すべての素材をダウンロードする
+		      </a>
+		    </li>
 		  </ul>
 		</>))}
       </MainArea>)

frontend/src/pages/materials/MaterialNewPage.tsx

@@ -17,7 +17,7 @@ import { useValidationErrors } from '@/lib/useValidationErrors'
 
 import type { FC } from 'react'
 
-type MaterialFormField = 'tag' | 'file' | 'url'
+type MaterialFormField = 'tag' | 'file' | 'url' | 'exportPaths'
 
 
 const MaterialNewPage: FC = () => {
@@ -32,6 +32,7 @@ const MaterialNewPage: FC = () => {
   const [sending, setSending] = useState (false)
   const [tag, setTag] = useState (tagQuery)
   const [url, setURL] = useState ('')
+  const [exportPath, setExportPath] = useState ('')
   const { baseErrors, fieldErrors, clearValidationErrors, applyValidationError } =
       useValidationErrors<MaterialFormField> ()
 
@@ -45,6 +46,7 @@ const MaterialNewPage: FC = () => {
       formData.append ('file', file)
     if (url)
       formData.append ('url', url)
+    formData.append ('export_paths[legacy_drive]', exportPath)
 
     try
     {
@@ -133,6 +135,20 @@ const MaterialNewPage: FC = () => {
 		    className={inputClass (invalid)}/>)}
 	  </FormField>
 
+	  <FormField
+	      label="ZIP 出力パス"
+	      messages={fieldErrors.exportPaths}>
+	    {({ describedBy, invalid }) => (
+		<input
+		    type="text"
+		    value={exportPath}
+		    onChange={e => setExportPath (e.target.value)}
+		    placeholder="伊地知ニジカ/表情/泣き.png"
+		    aria-describedby={describedBy}
+		    aria-invalid={invalid}
+		    className={inputClass (invalid)}/>)}
+	  </FormField>
+
 	  {/* 送信 */}
 	  <Button
 	      onClick={handleSubmit}

frontend/src/pages/tags/TagDetailPage.tsx

@@ -19,7 +19,12 @@ import type { FC, FormEvent } from 'react'
 
 import type { Category, Tag } from '@/types'
 
-type TagFormField = 'name' | 'category' | 'aliases' | 'parentTags'
+type TagFormField =
+    | 'name'
+    | 'category'
+    | 'aliases'
+    | 'parentTags'
+    | 'deprecated'
 
 
 const TagDetailPage: FC = () => {
@@ -35,6 +40,7 @@ const TagDetailPage: FC = () => {
   const [category, setCategory] = useState<Category> ('general')
   const [aliases, setAliases] = useState ('')
   const [parentTags, setParentTags] = useState ('')
+  const [deprecated, setDeprecated] = useState (false)
   const [disabled, setDisabled] = useState (true)
   const { baseErrors, fieldErrors, clearValidationErrors, applyValidationError } =
       useValidationErrors<TagFormField> ()
@@ -50,6 +56,7 @@ const TagDetailPage: FC = () => {
     formData.append ('category', category)
     formData.append ('aliases', aliases)
     formData.append ('parent_tags', parentTags)
+    formData.append ('deprecated', deprecated ? '1' : '0')
 
     try
     {
@@ -59,6 +66,7 @@ const TagDetailPage: FC = () => {
       setCategory (data.category as Category)
       setAliases (data.aliases.join (' '))
       setParentTags (data.parents.map (t => t.name).join (' '))
+      setDeprecated (Boolean (data.deprecatedAt))
 
       qc.invalidateQueries ({ queryKey: postsKeys.root })
       qc.invalidateQueries ({ queryKey: tagsKeys.root })
@@ -82,6 +90,7 @@ const TagDetailPage: FC = () => {
     setCategory (tag.category as Category)
     setAliases (tag.aliases.join (' '))
     setParentTags (tag.parents.map (t => t.name).join (' '))
+    setDeprecated (Boolean (tag.deprecatedAt))
     setDisabled (tag.category === 'nico')
   }, [tag])
 
@@ -165,6 +174,17 @@ const TagDetailPage: FC = () => {
 		      </>)}
 		</FormField>
 
+		<FormField label="廃止済" messages={fieldErrors.deprecated}>
+		  {({ describedBy, invalid }) => (
+		      <input
+			  type="checkbox"
+			  disabled={disabled}
+			  checked={deprecated}
+			  onChange={e => setDeprecated (e.target.checked)}
+			  aria-describedby={describedBy}
+			  aria-invalid={invalid}/>)}
+		</FormField>
+
 		<div className="py-3">
 		  <button
 		      type="submit"

frontend/src/pages/tags/TagHistoryPage.tsx

@@ -20,17 +20,28 @@ import type { FC } from 'react'
 
 const renderDiff = (diff: { current: string | null; prev: string | null }) => (
     <>
-      {(diff.prev && diff.prev !== diff.current) && (
+      {diff.prev !== diff.current
+       ? (
 	  <>
 	    <del className="text-red-600 dark:text-red-400">
-	      {diff.prev}
+	      {diff.prev && <>{diff.prev}<br/></>}
 	    </del>
-	    {diff.current && <br/>}
-	  </>)}
-      {diff.current}
+	    <ins className="text-green-600 dark:text-green-400">
+	      {diff.current}
+	    </ins>
+	  </>)
+       : diff.current}
     </>)
 
 
+const tagStateLabel = (deprecatedAt: string | null) => deprecatedAt ? '廃止' : ''
+
+
+const renderStateDiff = (diff: { current: string | null; prev: string | null }) =>
+    renderDiff ({ current: tagStateLabel (diff.current),
+		  prev: tagStateLabel (diff.prev) })
+
+
 const TagHistoryPage: FC = () => {
   const location = useLocation ()
   const query = new URLSearchParams (location.search)
@@ -72,6 +83,8 @@ const TagHistoryPage: FC = () => {
 		    <col className="w-96"/>
 		    {/* カテゴリ */}
 		    <col className="w-96"/>
+		    {/* 状態 */}
+		    <col className="w-32"/>
 		    {/* 別名 */}
 		    <col className="w-[48rem]"/>
 		    {/* 上位タグ */}
@@ -87,6 +100,7 @@ const TagHistoryPage: FC = () => {
 		      <th className="p-2 text-left">版</th>
 		      <th className="p-2 text-left">名称</th>
 		      <th className="p-2 text-left">カテゴリ</th>
+		      <th className="p-2 text-left">状態</th>
 		      <th className="p-2 text-left">別名</th>
 		      <th className="p-2 text-left">上位タグ</th>
 		      <th className="p-2 text-left">更新日時</th>
@@ -106,6 +120,9 @@ const TagHistoryPage: FC = () => {
 				prev: (change.category.prev
 				       && CATEGORY_NAMES[change.category.prev]) })}
 			  </td>
+			  <td className="p-2 break-all">
+			    {renderStateDiff (change.deprecatedAt)}
+			  </td>
 			  <td className="p-2">
 			    {change.aliases.map ((tag, i) => (
 				tag.type === 'added'
@@ -178,6 +195,7 @@ const TagHistoryPage: FC = () => {
 					`/tags/${ change.tagId }`,
 					{ name: change.name.current,
 					  category: change.category.current,
+					  deprecated: change.deprecatedAt.current ? '1' : '0',
 					  aliases:
 					      change.aliases
 					      .filter (t => t.type !== 'removed')
@@ -211,4 +229,5 @@ const TagHistoryPage: FC = () => {
       </MainArea>)
 }
 
-export default TagHistoryPage
+
+export default TagHistoryPage

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

@@ -14,13 +14,22 @@ vi.mock ('@/lib/tags', () => tagsApi)
 describe ('TagListPage', () => {
   it ('loads tags from URL filters and renders the results table', async () => {
     tagsApi.fetchTags.mockResolvedValueOnce ({
-      tags: [buildTag ({ id: 7, name: '虹夏', category: 'character', postCount: 99 })],
+      tags: [buildTag ({
+        id: 7,
+        name: '虹夏',
+        category: 'character',
+        postCount: 99,
+        deprecatedAt: '2026-06-01T00:00:00.000Z',
+      })],
       count: 1,
     })
 
     renderWithProviders (
         <TagListPage/>,
-        { route: '/tags?name=%E8%99%B9&category=character&page=3&post_count_gte=5' },
+        {
+          route:
+              '/tags?name=%E8%99%B9&category=character&page=3&post_count_gte=5&deprecated=1',
+        },
     )
 
     await waitFor (() => {
@@ -30,6 +39,7 @@ describe ('TagListPage', () => {
             category:     'character',
             page:         3,
             postCountGTE: 5,
+            deprecated:   true,
           }),
       )
     })
@@ -38,6 +48,8 @@ describe ('TagListPage', () => {
         '/tags/7',
     )
     expect (screen.getAllByText ('キャラクター').length).toBeGreaterThan (0)
+    expect (screen.getAllByRole ('combobox')[1]).toHaveValue ('1')
+    expect (screen.getAllByText ('廃止')).toHaveLength (2)
   })
 
   it ('navigates to a normalized search URL on submit', async () => {
@@ -46,7 +58,9 @@ describe ('TagListPage', () => {
     renderWithProviders (<TagListPage/>, { route: '/tags' })
 
     fireEvent.change (screen.getByRole ('textbox'), { target: { value: '虹夏' } })
-    fireEvent.change (screen.getByRole ('combobox'), { target: { value: 'character' } })
+    fireEvent.change (screen.getAllByRole ('combobox')[0], {
+      target: { value: 'character' },
+    })
     fireEvent.submit (screen.getByRole ('button', { name: '検索' }).closest ('form')!)
 
     await waitFor (() => {

frontend/src/pages/tags/TagListPage.tsx

@@ -29,6 +29,13 @@ const setIf = (qs: URLSearchParams, k: string, v: string | null) => {
 }
 
 
+const boolFromQuery = (value: string | null): boolean =>
+    ['1', 'true', 'on', 'yes', ''].includes ((value ?? '').toLowerCase ())
+
+
+const tagStateLabel = (deprecatedAt: string | null) => deprecatedAt ? '廃止' : ''
+
+
 const TagListPage: FC = () => {
   const location = useLocation ()
 
@@ -48,6 +55,9 @@ const TagListPage: FC = () => {
   const qCreatedTo = query.get ('created_to') ?? ''
   const qUpdatedFrom = query.get ('updated_from') ?? ''
   const qUpdatedTo = query.get ('updated_to') ?? ''
+  const qDeprecated = query.has ('deprecated')
+      ? boolFromQuery (query.get ('deprecated'))
+      : null
   const order = (query.get ('order') || 'post_count:desc') as FetchTagsOrder
 
   const [name, setName] = useState ('')
@@ -58,6 +68,7 @@ const TagListPage: FC = () => {
   const [createdTo, setCreatedTo] = useState<string | null> (null)
   const [updatedFrom, setUpdatedFrom] = useState<string | null> (null)
   const [updatedTo, setUpdatedTo] = useState<string | null> (null)
+  const [deprecated, setDeprecated] = useState<boolean | null> (null)
 
   const keys = {
       page, limit, order,
@@ -69,7 +80,8 @@ const TagListPage: FC = () => {
       createdFrom: qCreatedFrom,
       createdTo: qCreatedTo,
       updatedFrom: qUpdatedFrom,
-      updatedTo: qUpdatedTo }
+      updatedTo: qUpdatedTo,
+      deprecated: qDeprecated }
   const { data, isLoading: loading } = useQuery ({
       queryKey: tagsKeys.index (keys),
       queryFn: () => fetchTags (keys) })
@@ -85,10 +97,11 @@ const TagListPage: FC = () => {
     setCreatedTo (qCreatedTo)
     setUpdatedFrom (qUpdatedFrom)
     setUpdatedTo (qUpdatedTo)
+    setDeprecated (qDeprecated)
 
     document.querySelector ('table')?.scrollIntoView ({ behavior: 'smooth' })
   }, [location.search, qCategory, qCreatedFrom, qCreatedTo, qName, qPostCountGTE,
-      qPostCountLTE, qUpdatedFrom, qUpdatedTo])
+      qPostCountLTE, qUpdatedFrom, qUpdatedTo, qDeprecated])
 
   const handleSearch = (e: FormEvent) => {
     e.preventDefault ()
@@ -104,6 +117,8 @@ const TagListPage: FC = () => {
     setIf (qs, 'created_to', createdTo)
     setIf (qs, 'updated_from', updatedFrom)
     setIf (qs, 'updated_to', updatedTo)
+    if (deprecated != null)
+      qs.set ('deprecated', deprecated ? '1' : '0')
     qs.set ('page', '1')
     qs.set ('order', order)
 
@@ -201,6 +216,21 @@ const TagListPage: FC = () => {
 		  </>)}
 	    </FormField>
 
+	    <FormField label="状態">
+	      {({ invalid }) => (
+		  <select
+		      value={deprecated == null ? '' : (deprecated ? '1' : '0')}
+		      onChange={e => setDeprecated (
+			  e.target.value === ''
+			  ? null
+			  : e.target.value === '1')}
+		      className={inputClass (invalid)}>
+		    <option value="">&nbsp;</option>
+		    <option value="0">有効</option>
+		    <option value="1">廃止</option>
+		  </select>)}
+	    </FormField>
+
 	    <div className="py-3">
 	      <button
 		  type="submit"
@@ -219,6 +249,7 @@ const TagListPage: FC = () => {
 		    <col className="w-72"/>
 		    <col className="w-16"/>
 		    <col className="w-48"/>
+		    <col className="w-32"/>
 		    <col className="w-72"/>
 		    <col className="w-48"/>
 		    <col className="w-56"/>
@@ -249,6 +280,7 @@ const TagListPage: FC = () => {
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">状態</th>
 		      <th className="p-2 text-left whitespace-nowrap">別名</th>
 		      <th className="p-2 text-left whitespace-nowrap">上位タグ</th>
 		      <th className="p-2 text-left whitespace-nowrap">
@@ -280,6 +312,7 @@ const TagListPage: FC = () => {
 			  </td>
 			  <td className="p-2 text-right">{row.postCount}</td>
 			  <td className="p-2">{CATEGORY_NAMES[row.category]}</td>
+			  <td className="p-2">{tagStateLabel (row.deprecatedAt)}</td>
 			  <td className="p-2">{row.aliases.join (' ')}</td>
 			  <td className="p-2">
 			    {row.parents.map (t => (

frontend/src/pages/wiki/WikiDetailPage.test.tsx

@@ -0,0 +1,54 @@
+import { screen } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { describe, expect, it, vi } from 'vitest'
+
+import WikiDetailPage from '@/pages/wiki/WikiDetailPage'
+import { buildTag, buildWikiPage } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPage:        vi.fn (),
+  fetchWikiPageByTitle: vi.fn (),
+}))
+
+const tagsApi = vi.hoisted (() => ({
+  fetchTagByName: vi.fn (),
+}))
+
+const postsApi = vi.hoisted (() => ({
+  fetchPosts: vi.fn (),
+}))
+
+vi.mock ('@/lib/wiki', () => wikiApi)
+vi.mock ('@/lib/tags', () => tagsApi)
+vi.mock ('@/lib/posts', () => postsApi)
+
+describe ('WikiDetailPage', () => {
+  it ('renders deprecated state outside the wiki title link', async () => {
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce (buildWikiPage ({
+      title:        '旧タグ',
+      deprecatedAt: '2026-06-01T00:00:00.000Z',
+    }))
+    tagsApi.fetchTagByName.mockResolvedValueOnce (buildTag ({
+      name:         '旧タグ',
+      deprecatedAt: '2026-06-01T00:00:00.000Z',
+    }))
+    postsApi.fetchPosts.mockResolvedValueOnce ({ posts: [], count: 0 })
+
+    renderWithProviders (
+        <Routes>
+          <Route path="/wiki/:title" element={<WikiDetailPage/>}/>
+        </Routes>,
+        { route: '/wiki/%E6%97%A7%E3%82%BF%E3%82%B0' },
+    )
+
+    const marker = await screen.findByText ('（廃止）')
+    const heading = marker.closest ('h1')
+    const link = screen.getByRole ('link', { name: '旧タグ' })
+
+    expect (heading).not.toBeNull ()
+    expect (heading!).toHaveTextContent ('旧タグ（廃止）')
+    expect (link).toBeInTheDocument ()
+    expect (marker.closest ('a')).toBeNull ()
+  })
+})

frontend/src/pages/wiki/WikiDetailPage.tsx

@@ -39,6 +39,7 @@ const WikiDetailPage: FC = () => {
       queryFn:  () => fetchWikiPageByTitle (title, { version }) })
 
   const effectiveTitle = wikiPage?.title ?? title
+  const deprecated = wikiPage?.deprecatedAt != null
 
   const { data: tag } = useQuery ({
       enabled:  Boolean (effectiveTitle),
@@ -88,7 +89,7 @@ const WikiDetailPage: FC = () => {
   return (
       <MainArea>
 	<Helmet>
-	  <title>{`${ title } Wiki | ${ SITE_TITLE }`}</title>
+	  <title>{`${ effectiveTitle }${ deprecated ? '（廃止）' : '' } Wiki | ${ SITE_TITLE }`}</title>
 	  {!(wikiPage?.body) && <meta name="robots" content="noindex"/>}
 	</Helmet>
 
@@ -110,10 +111,13 @@ const WikiDetailPage: FC = () => {
 
 	<article className="prose dark:prose-invert mx-auto p-4">
 	  <h1 className="prose-a:no-underline">
-	    <TagLink tag={tag ?? defaultTag}
+	    <TagLink tag={tag ?? { ...defaultTag,
+				   name: effectiveTitle,
+				   deprecatedAt: wikiPage?.deprecatedAt ?? null }}
 		     withWiki={false}
 		     withCount={false}
 		     {...(version && { to: `/wiki/${ encodeURIComponent (title) }` })}/>
+	    {deprecated && <span>（廃止）</span>}
 	  </h1>
 	  {loading ? <div>Loading...</div> : <WikiBody title={title} body={wikiPage?.body}/>}
 

frontend/src/pages/wiki/WikiDiffPage.test.tsx

@@ -16,6 +16,7 @@ describe ('WikiDiffPage', () => {
     api.apiGet.mockResolvedValueOnce ({
       wikiPageId:      3,
       title:           '差分対象',
+      deprecatedAt:    null,
       olderRevisionId: 1,
       newerRevisionId: 2,
       diff: [
@@ -43,4 +44,26 @@ describe ('WikiDiffPage', () => {
     expect (screen.getByText ('added line')).toBeInTheDocument ()
     expect (screen.getByText ('removed line')).toBeInTheDocument ()
   })
+
+  it ('appends deprecated state to the wiki title', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      wikiPageId:      3,
+      title:           '廃止 Wiki',
+      deprecatedAt:    '2026-06-01T00:00:00.000Z',
+      olderRevisionId: 1,
+      newerRevisionId: 2,
+      diff:            [],
+    })
+
+    renderWithProviders (
+        <Routes>
+          <Route path="/wiki/:id/diff" element={<WikiDiffPage/>}/>
+        </Routes>,
+        { route: '/wiki/3/diff?from=1&to=2' },
+    )
+
+    expect (await screen.findByRole ('heading', {
+      name: '廃止 Wiki（廃止）',
+    })).toBeInTheDocument ()
+  })
 })

frontend/src/pages/wiki/WikiDiffPage.tsx

@@ -23,6 +23,9 @@ const WikiDiffPage: FC = () => {
   const query = new URLSearchParams (location.search)
   const from = query.get ('from')
   const to = query.get ('to')
+  const displayTitle = diff
+      ? `${ diff.title }${ diff.deprecatedAt != null ? '（廃止）' : '' }`
+      : ''
 
   useEffect (() => {
     void (async () => {
@@ -33,9 +36,9 @@ const WikiDiffPage: FC = () => {
   return (
       <MainArea>
 	<Helmet>
-	  <title>{`Wiki 差分: ${ diff?.title } | ${ SITE_TITLE }`}</title>
+	  <title>{`Wiki 差分: ${ displayTitle } | ${ SITE_TITLE }`}</title>
 	</Helmet>
-	<PageTitle>{diff?.title}</PageTitle>
+	<PageTitle>{displayTitle}</PageTitle>
 	<div className="prose mx-auto p-4">
 	  {diff
 	   ? (

frontend/src/pages/wiki/WikiHistoryPage.test.tsx

@@ -0,0 +1,38 @@
+import { screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import WikiHistoryPage from '@/pages/wiki/WikiHistoryPage'
+import { renderWithProviders } from '@/test/render'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('WikiHistoryPage', () => {
+  it ('renders deprecated state outside the wiki title link', async () => {
+    api.apiGet.mockResolvedValueOnce ([{
+      revisionId:  2,
+      pred:        1,
+      succ:        null,
+      wikiPage:    {
+	id:           3,
+	title:        '旧タグ',
+	deprecatedAt: '2026-06-01T00:00:00.000Z',
+      },
+      user:        { id: 4, name: 'tester' },
+      kind:        'content',
+      message:     'updated',
+      timestamp:   '2026-06-02T00:00:00.000Z',
+    }])
+
+    renderWithProviders (<WikiHistoryPage/>)
+
+    const link = await screen.findByRole ('link', { name: '旧タグ' })
+    const marker = screen.getByText ('（廃止）')
+
+    expect (link).toHaveAttribute ('href', '/wiki/%E6%97%A7%E3%82%BF%E3%82%B0?version=2')
+    expect (marker.closest ('a')).toBeNull ()
+  })
+})

frontend/src/pages/wiki/WikiHistoryPage.tsx

@@ -59,6 +59,7 @@ const WikiHistoryPage: FC = () => {
 			to={`/wiki/${ encodeURIComponent (change.wikiPage.title) }?version=${ change.revisionId }`}>
 		      {change.wikiPage.title}
 		    </PrefetchLink>
+		    {change.wikiPage.deprecatedAt != null && <span>（廃止）</span>}
 		  </td>
 		  <td className="p-2">
 		    {change.pred == null ? '新規' : '更新'}

frontend/src/pages/wiki/WikiSearchPage.test.tsx

@@ -42,4 +42,21 @@ describe ('WikiSearchPage', () => {
     })
     expect (await screen.findByRole ('link', { name: '検索結果' })).toBeInTheDocument ()
   })
+
+  it ('marks deprecated wiki tags in the result title', async () => {
+    api.apiGet.mockResolvedValueOnce ([
+        buildWikiPage ({
+            title:        '旧タグ',
+            deprecatedAt: '2026-06-01T00:00:00.000Z',
+        }),
+    ])
+
+    renderWithProviders (<WikiSearchPage/>)
+
+    const link = await screen.findByRole ('link', { name: '旧タグ' })
+    const marker = screen.getByText ('（廃止）')
+
+    expect (link).toBeInTheDocument ()
+    expect (marker.closest ('a')).toBeNull ()
+  })
 })

frontend/src/pages/wiki/WikiSearchPage.tsx

@@ -86,6 +86,7 @@ const WikiSearchPage: FC = () => {
 		      <PrefetchLink to={`/wiki/${ encodeURIComponent (page.title) }`}>
 			{page.title}
 		      </PrefetchLink>
+		      {page.deprecatedAt != null && <span>（廃止）</span>}
 		    </td>
 		    <td className="p-2">
 		      {dateString (page.updatedAt)}

frontend/src/test/factories.ts

@@ -13,6 +13,7 @@ export const buildTag = (overrides: Partial<Tag> = {}): Tag => ({
   id:             1,
   name:           'テストタグ',
   category:       'general',
+  deprecatedAt:   null,
   aliases:        [],
   parents:        [],
   postCount:      12,
@@ -57,6 +58,7 @@ export const buildUser = (overrides: Partial<User> = {}): User => ({
 export const buildWikiPage = (overrides: Partial<WikiPage> = {}): WikiPage => ({
   id:            1,
   title:         'テストWiki',
+  deprecatedAt:  null,
   createdUserId: 1,
   updatedUserId: 1,
   createdAt:     '2026-01-02T03:04:05.000Z',
@@ -69,16 +71,21 @@ export const buildWikiPage = (overrides: Partial<WikiPage> = {}): WikiPage => ({
 })
 
 export const buildMaterial = (overrides: Partial<Material> = {}): Material => ({
-  id:            1,
-  tag:           buildTag (),
-  file:          null,
-  url:           null,
-  wikiPageBody:  null,
-  contentType:   null,
-  createdAt:     '2026-01-02T03:04:05.000Z',
-  createdByUser: { id: 1, name: 'creator' },
-  updatedAt:     '2026-01-03T03:04:05.000Z',
-  updatedByUser: { id: 2, name: 'updater' },
+  id:                    1,
+  versionNo:             1,
+  tag:                   buildTag (),
+  file:                  null,
+  url:                   null,
+  wikiPageBody:          null,
+  contentType:           null,
+  fileSuppressedAt:      null,
+  fileSuppressionReason: null,
+  exportPaths:           {},
+  exportItems:           [],
+  createdAt:             '2026-01-02T03:04:05.000Z',
+  createdByUser:         { id: 1, name: 'creator' },
+  updatedAt:             '2026-01-03T03:04:05.000Z',
+  updatedByUser:         { id: 2, name: 'updater' },
   ...overrides,
 })
 

frontend/src/types.ts

@@ -39,18 +39,19 @@ export type FetchTagsOrderField =
     | 'updated_at'
 
 export type FetchTagsParams = {
-    post:         number | null
-    name:         string
-    category:     Category | null
-    postCountGTE: number
-    postCountLTE: number | null
-    createdFrom:  string
-    createdTo:    string
-    updatedFrom:  string
-    updatedTo:    string
-    page:         number
-    limit:        number
-    order:        FetchTagsOrder }
+    post:           number | null
+    name:           string
+    category:       Category | null
+    postCountGTE:   number
+    postCountLTE:   number | null
+    createdFrom:    string
+    createdTo:      string
+    updatedFrom:    string
+    updatedTo:      string
+    deprecated:     boolean | null
+    page:           number
+    limit:          number
+    order:          FetchTagsOrder }
 
 export type FetchNicoTagsParams = {
     name:       string
@@ -65,16 +66,27 @@ export type FetchNicoTagsOrder = `${ FetchNicoTagsOrderField }:${ 'asc' | 'desc'
 export type FetchNicoTagsOrderField = 'name' | 'created_at' | 'updated_at'
 
 export type Material = {
-    id:             number
-    tag:            Tag
-    file:           string | null
-    url:            string | null
-    wikiPageBody?:  string | null
-    contentType:    string | null
-    createdAt:      string
-    createdByUser:  { id: number; name: string }
-    updatedAt:      string
-    updatedByUser:  { id: number; name: string } }
+    id:                     number
+    versionNo:              number
+    tag:                    Tag
+    file:                   string | null
+    url:                    string | null
+    wikiPageBody?:          string | null
+    contentType:            string | null
+    fileSuppressedAt:       string | null
+    fileSuppressionReason:  string | null
+    exportPaths:            Record<string, string>
+    exportItems:            MaterialExportItem[]
+    createdAt:              string
+    createdByUser:          { id: number; name: string }
+    updatedAt:              string
+    updatedByUser:          { id: number; name: string } }
+
+export type MaterialExportItem = {
+    id:          number
+    profile:     string
+    exportPath:  string
+    enabled:     boolean }
 
 export type Menu = MenuItem[]
 
@@ -196,6 +208,7 @@ export type Tag = {
     id:             number
     name:           string
     category:       Category
+    deprecatedAt:   string | null
     aliases:        string[]
     parents:        Tag[]
     postCount:      number
@@ -213,6 +226,7 @@ export type TagVersion = {
     eventType:              'create' | 'update' | 'discard' | 'restore'
     name:                   { current: string; prev: string | null }
     category:               { current: Category; prev: Category | null }
+    deprecatedAt:           { current: string | null; prev: string | null }
     aliases:                { name: string; type: 'context' | 'added' | 'removed' }[]
     parentTags:             { tag: Tag; type: 'context' | 'added' | 'removed' }[]
     createdAt:              string
@@ -296,6 +310,7 @@ export type ViewFlagBehavior = typeof ViewFlagBehavior[keyof typeof ViewFlagBeha
 export type WikiPage = {
     id:             number
     title:          string
+    deprecatedAt:   string | null
     createdUserId:  number
     updatedUserId:  number
     createdAt:      string
@@ -309,7 +324,7 @@ export type WikiPageChange = {
     revisionId: number
     pred:       number | null
     succ:       null
-    wikiPage:   Pick<WikiPage, 'id' | 'title'>
+    wikiPage:   Pick<WikiPage, 'id' | 'title' | 'deprecatedAt'>
     user:       Pick<User, 'id' | 'name'>
     kind:       'content' | 'redirect'
     message:    string | null
@@ -318,6 +333,7 @@ export type WikiPageChange = {
 export type WikiPageDiff = {
     wikiPageId:       number
     title:            string
+    deprecatedAt:     string | null
     olderRevisionId:  number | null
     newerRevisionId:  number
     diff:             WikiPageDiffDiff[] }

frontend/tsconfig.app.json

@@ -27,5 +27,6 @@
       "@/*": ["*"]
     }
   },
-  "include": ["src"]
+  "include": ["src"],
+  "exclude": ["src/**/*.test.ts", "src/**/*.test.tsx", "src/test"]
 }