#306

backend/app/controllers/material_sync_suppressions_controller.rb

@@ -0,0 +1,49 @@
+class MaterialSyncSuppressionsController < ApplicationController
+  def index
+    return head :unauthorized unless current_user
+    return head :forbidden unless current_user.gte_member?
+
+    suppressions =
+        MaterialSyncSuppression
+        .includes(:created_by_user)
+        .order(created_at: :desc, id: :desc)
+
+    render json: { suppressions: suppressions.map { |s| repr(s) } }
+  end
+
+  def create
+    return head :unauthorized unless current_user
+    return head :forbidden unless current_user.gte_member?
+
+    suppression =
+        MaterialSyncSuppressionRegistrar.create!(suppression_params,
+                                                 created_by_user: current_user)
+
+    render json: repr(suppression), status: :created
+  rescue ActiveRecord::RecordInvalid => e
+    render_validation_error e.record
+  end
+
+  private
+
+  def suppression_params
+    params.permit(:source_kind,
+                  :source_uri,
+                  :drive_path,
+                  :drive_file_id,
+                  :reason)
+  end
+
+  def repr suppression
+    { id: suppression.id,
+      source_kind: suppression.source_kind,
+      source_uri: suppression.source_uri,
+      drive_path: suppression.drive_path,
+      drive_file_id: suppression.drive_file_id,
+      normalized_source_key: suppression.normalized_source_key,
+      reason: suppression.reason,
+      created_by_user: suppression.created_by_user&.as_json(UserRepr::BASE),
+      created_at: suppression.created_at,
+      updated_at: suppression.updated_at }
+  end
+end

backend/app/controllers/materials_controller.rb

@@ -17,8 +17,6 @@ class MaterialsController < ApplicationController
                           thumbnail_attachment: :blob,
                           file_attachment: :blob,
                           tag: :tag_name)
-    q = q.where(file_suppressed_at: nil) if filters[:suppression] == 'active'
-    q = q.where.not(file_suppressed_at: nil) if filters[:suppression] == 'suppressed'
     q = q.where(tag_id: nil) if filters[:tag_state] == 'untagged'
     q = q.where.not(tag_id: nil) if filters[:tag_state] == 'tagged'
     q = q.where('materials.created_at >= ?', filters[:created_from]) if filters[:created_from]
@@ -136,7 +134,6 @@ class MaterialsController < ApplicationController
         material.assign_attributes(tag:, url:, updated_by_user: current_user)
         if uploaded_blob
           material.file.attach(uploaded_blob)
-          clear_file_suppression!(material)
         elsif params.key?(:url) && url.present? && file.blank?
           material.file.detach
         end
@@ -182,37 +179,6 @@ class MaterialsController < ApplicationController
               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 material_index_filters
@@ -225,9 +191,6 @@ class MaterialsController < ApplicationController
       media_kind = 'all'
     end
 
-    suppression = params[:suppression].to_s.presence
-    suppression = 'active' unless ['active', 'suppressed', 'all'].include?(suppression)
-
     sort = params[:sort].to_s.presence
     unless ['created_at', 'updated_at', 'tag_name', 'media_kind', 'file_byte_size',
             'version_no', 'id'].include?(sort)
@@ -240,7 +203,6 @@ class MaterialsController < ApplicationController
     { q: params[:q].to_s.strip.presence,
       tag_state:,
       media_kind:,
-      suppression:,
       created_from: parse_time_param(:created_from),
       created_to: parse_time_param(:created_to),
       updated_from: parse_time_param(:updated_from),
@@ -410,26 +372,6 @@ class MaterialsController < ApplicationController
     file.tempfile.rewind if file&.tempfile
   end
 
-  def clear_file_suppression! material
-    material.file_suppressed_at = nil
-    material.file_suppressed_by_user = nil
-    material.file_suppression_reason = nil
-  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, allow_download: true) }
-  end
-
   def render_material_import_block block
     render_validation_error fields: { file: ["抑止された素材です: #{ block.reason }"] }
   end

backend/app/models/material.rb

@@ -9,7 +9,6 @@ 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
@@ -17,13 +16,17 @@ class Material < ApplicationRecord
   has_one_attached :file, dependent: :purge
   has_one_attached :thumbnail, dependent: :purge
 
+  before_validation :assign_normalized_source_key
+
   validates :tag_id, presence: true, uniqueness: true
+  validates :source_kind,
+            inclusion: { in: MaterialSyncSuppression::SOURCE_KINDS },
+            allow_blank: true
 
   validate :file_must_be_attached
   validate :tag_must_be_material_category
 
   def content_type
-    return nil if file_suppressed?
     return nil unless file&.attached?
 
     file.blob.content_type
@@ -41,14 +44,25 @@ class Material < ApplicationRecord
     file.blob.filename.to_s
   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 assign_normalized_source_key
+    if source_kind.blank?
+      self.normalized_source_key = nil
+      return
+    end
+
+    self.normalized_source_key =
+        MaterialSyncSuppression.normalize_source_key(source_kind:,
+                                                     source_uri:,
+                                                     drive_path: source_path,
+                                                     drive_file_id: source_file_id)
+  end
+
   def file_must_be_attached
     return if url.present? || file.attached?
 

backend/app/models/material_sync_suppression.rb

@@ -0,0 +1,68 @@
+class MaterialSyncSuppression < ApplicationRecord
+  SOURCE_KINDS = [
+    'uri',
+    'google_drive_path',
+    'google_drive_file',
+    'legacy_drive_path'
+  ].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
+
+  before_validation :assign_normalized_source_key
+
+  validates :source_kind, presence: true, inclusion: { in: SOURCE_KINDS }
+  validates :reason, presence: true, inclusion: { in: REASONS }
+  validates :normalized_source_key, presence: true, uniqueness: true
+  validate :source_value_must_be_present
+
+  def self.normalize_source_key source_kind:,
+                                source_uri: nil,
+                                drive_path: nil,
+                                drive_file_id: nil,
+                                source_path: nil,
+                                source_file_id: nil
+    kind = source_kind.to_s
+    value =
+        case kind
+        when 'uri'
+          source_uri.to_s.strip
+        when 'google_drive_path', 'legacy_drive_path'
+          (source_path || drive_path).to_s.strip.gsub(%r{/+}, '/')
+        when 'google_drive_file'
+          (source_file_id || drive_file_id).to_s.strip
+        else
+          ''
+        end
+
+    return nil if kind.blank? || value.blank?
+
+    "#{ kind }:#{ value }"
+  end
+
+  private
+
+  def assign_normalized_source_key
+    self.normalized_source_key =
+        self.class.normalize_source_key(source_kind:,
+                                        source_uri:,
+                                        drive_path:,
+                                        drive_file_id:)
+  end
+
+  def source_value_must_be_present
+    return if normalized_source_key.present?
+
+    errors.add(:base, '同期元を指定してください．')
+  end
+end

backend/app/models/material_version.rb

@@ -2,8 +2,7 @@ class MaterialVersion < ApplicationRecord
   EVENT_TYPE_MAP = { create: 'create',
                      update: 'update',
                      discard: 'discard',
-                     restore: 'restore',
-                     suppress: 'suppress' }.freeze
+                     restore: 'restore' }.freeze
 
   include VersionRecord
 

backend/app/representations/material_repr.rb

@@ -2,8 +2,9 @@
 
 
 module MaterialRepr
-  BASE = { only: [:id, :url, :version_no, :file_suppressed_at,
-                  :file_suppression_reason, :created_at, :updated_at],
+  BASE = { only: [:id, :url, :version_no, :source_kind, :source_uri,
+                  :source_path, :source_file_id, :normalized_source_key,
+                  :created_at, :updated_at],
            methods: [:content_type],
            include: { tag: TagRepr::BASE,
                       created_by_user: UserRepr::BASE,
@@ -13,7 +14,7 @@ module MaterialRepr
 
   def base material, host:
     material.as_json(BASE).merge(
-        file: if material.file.attached? && !material.file_suppressed?
+        file: if material.file.attached?
                 Rails.application.routes.url_helpers.rails_storage_proxy_url(
                     material.file, host:)
               end,
@@ -34,6 +35,11 @@ module MaterialRepr
     { id: material.id,
       version_no: material.version_no,
       url: material.url,
+      source_kind: material.source_kind,
+      source_uri: material.source_uri,
+      source_path: material.source_path,
+      source_file_id: material.source_file_id,
+      normalized_source_key: material.normalized_source_key,
       tag: compact_tag(material.tag),
       thumbnail: thumbnail_url(material, host:),
       thumbnail_fallback_text: thumbnail_fallback_text(material),
@@ -41,7 +47,6 @@ module MaterialRepr
       media_kind: media_kind(material),
       content_type: material.content_type,
       file_byte_size: material.file_byte_size,
-      file_suppressed_at: material.file_suppressed_at,
       created_at: material.created_at,
       updated_at: material.updated_at,
       export_paths: export_paths(material),
@@ -68,7 +73,6 @@ module MaterialRepr
   end
 
   def thumbnail_url material, host:
-    return nil if material.file_suppressed?
     return nil unless material.thumbnail.attached?
 
     Rails.application.routes.url_helpers.rails_storage_proxy_url(
@@ -84,7 +88,6 @@ module MaterialRepr
   end
 
   def media_kind material
-    return 'suppressed' if material.file_suppressed?
     return 'url_only' unless material.file.attached?
 
     content_type = material.file.blob.content_type.to_s

backend/app/services/material_sync_importer.rb

@@ -0,0 +1,49 @@
+class MaterialSyncImporter
+  Result = Struct.new(:material, :suppressed, :suppression, keyword_init: true)
+
+  def self.import! attributes
+    new(attributes).import!
+  end
+
+  def initialize attributes
+    @attributes = attributes
+  end
+
+  def import!
+    source = source_attributes
+    key = normalized_source_key(source)
+    raise ArgumentError, 'normalized_source_key is required for material sync' if key.blank?
+
+    suppression = MaterialSyncSuppressionMatcher.match(**source)
+    return Result.new(material: nil, suppressed: true, suppression:) if suppression
+
+    material =
+        Material
+        .unscoped
+        .find_or_initialize_by(normalized_source_key: key)
+    material.assign_attributes(material_attributes.merge(source))
+    material.save!
+
+    Result.new(material:, suppressed: false, suppression: nil)
+  end
+
+  private
+
+  def source_attributes
+    { source_kind: @attributes[:source_kind],
+      source_uri: @attributes[:source_uri],
+      source_path: @attributes[:source_path],
+      source_file_id: @attributes[:source_file_id] }
+  end
+
+  def normalized_source_key source
+    MaterialSyncSuppression.normalize_source_key(source_kind: source[:source_kind],
+                                                 source_uri: source[:source_uri],
+                                                 source_path: source[:source_path],
+                                                 source_file_id: source[:source_file_id])
+  end
+
+  def material_attributes
+    @attributes.except(:source_kind, :source_uri, :source_path, :source_file_id)
+  end
+end

backend/app/services/material_sync_suppression_matcher.rb

@@ -0,0 +1,22 @@
+class MaterialSyncSuppressionMatcher
+  def self.match source_kind:,
+                 source_uri: nil,
+                 drive_path: nil,
+                 drive_file_id: nil,
+                 source_path: nil,
+                 source_file_id: nil
+    key = MaterialSyncSuppression.normalize_source_key(source_kind:,
+                                                       source_uri:,
+                                                       drive_path:,
+                                                       drive_file_id:,
+                                                       source_path:,
+                                                       source_file_id:)
+    return nil if key.blank?
+
+    MaterialSyncSuppression.find_by(normalized_source_key: key)
+  end
+
+  def self.suppressed?(...)
+    match(...).present?
+  end
+end

backend/app/services/material_sync_suppression_registrar.rb

@@ -0,0 +1,37 @@
+class MaterialSyncSuppressionRegistrar
+  def self.create! attributes, created_by_user:
+    new(attributes, created_by_user:).create!
+  end
+
+  def initialize attributes, created_by_user:
+    @attributes = attributes
+    @created_by_user = created_by_user
+  end
+
+  def create!
+    suppression = nil
+
+    MaterialSyncSuppression.transaction do
+      suppression = MaterialSyncSuppression.create!(
+          @attributes.merge(created_by_user: @created_by_user))
+      discard_existing_materials!(suppression)
+    end
+
+    suppression
+  end
+
+  private
+
+  def discard_existing_materials! suppression
+    Material.unscoped
+            .kept
+            .where(normalized_source_key: suppression.normalized_source_key)
+            .find_each do |material|
+      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: @created_by_user)
+      material.discard!
+      MaterialVersionRecorder.record!(material:,
+                                      event_type: :discard,
+                                      created_by_user: @created_by_user)
+    end
+  end
+end

backend/app/services/material_version_recorder.rb

@@ -1,5 +1,5 @@
 class MaterialVersionRecorder < VersionRecorder
-  EVENT_TYPES = ['create', 'update', 'discard', 'restore', 'suppress'].freeze
+  EVENT_TYPES = ['create', 'update', 'discard', 'restore'].freeze
 
   def self.record! material:, event_type:, created_by_user:, file_snapshot: nil
     new(material:, event_type:, created_by_user:, file_snapshot:).record!
@@ -40,9 +40,7 @@ class MaterialVersionRecorder < VersionRecorder
       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 }
+      file_sha256: file_snapshot[:file_sha256] }
   end
 
   def build_file_snapshot blob

backend/app/services/material_zip_exporter.rb

@@ -40,7 +40,6 @@ class MaterialZipExporter
            .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

backend/config/routes.rb

@@ -114,9 +114,6 @@ Rails.application.routes.draw do
   end
 
   get 'materials/download.zip', to: 'materials#download'
-  resources :materials, only: [:index, :show, :create, :update, :destroy] do
-    member do
-      patch :suppress_file
-    end
-  end
+  resources :material_sync_suppressions, path: 'materials/suppressions', only: [:index, :create]
+  resources :materials, only: [:index, :show, :create, :update, :destroy]
 end

backend/db/migrate/20260625000000_reconcile_material_sync_suppressions.rb

@@ -0,0 +1,118 @@
+class ReconcileMaterialSyncSuppressions < ActiveRecord::Migration[8.0]
+  MATERIAL_VERSION_EVENT_CONSTRAINT = 'material_versions_event_type_valid'
+
+  def up
+    ensure_material_sync_suppressions!
+    ensure_material_source_columns!
+    ensure_material_active_source_key!
+    remove_material_file_suppression!
+    remove_material_version_file_suppression!
+    reconcile_material_version_event_constraint!
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+
+  private
+
+  def ensure_material_sync_suppressions!
+    return if table_exists?(:material_sync_suppressions)
+
+    create_table :material_sync_suppressions do |t|
+      t.string :source_kind, null: false
+      t.string :source_uri
+      t.string :drive_path
+      t.string :drive_file_id
+      t.string :normalized_source_key, null: false
+      t.string :reason, null: false
+      t.references :created_by_user, foreign_key: { to_table: :users }
+      t.timestamps
+
+      t.index :normalized_source_key, unique: true
+      t.index :source_kind
+      t.index :drive_file_id
+    end
+  end
+
+  def ensure_material_source_columns!
+    add_column :materials, :source_kind, :string unless column_exists?(:materials, :source_kind)
+    add_column :materials, :source_uri, :string unless column_exists?(:materials, :source_uri)
+    add_column :materials, :source_path, :string unless column_exists?(:materials, :source_path)
+    unless column_exists?(:materials, :source_file_id)
+      add_column :materials, :source_file_id, :string
+    end
+    unless column_exists?(:materials, :normalized_source_key)
+      add_column :materials, :normalized_source_key, :string
+    end
+
+    if index_exists?(:materials, :normalized_source_key)
+      remove_index :materials, column: :normalized_source_key
+    end
+  end
+
+  def ensure_material_active_source_key!
+    unless column_exists?(:materials, :active_normalized_source_key)
+      change_table :materials do |t|
+        t.virtual :active_normalized_source_key,
+                  type: :string,
+                  as: 'IF(discarded_at IS NULL, normalized_source_key, NULL)',
+                  stored: false
+      end
+    end
+
+    return if index_exists?(:materials,
+                            :active_normalized_source_key,
+                            name: 'index_materials_on_active_normalized_source_key')
+
+    add_index :materials,
+              :active_normalized_source_key,
+              unique: true,
+              name: 'index_materials_on_active_normalized_source_key'
+  end
+
+  def remove_material_file_suppression!
+    if foreign_key_exists?(:materials, :users, column: :file_suppressed_by_user_id)
+      remove_foreign_key :materials, column: :file_suppressed_by_user_id
+    end
+
+    if index_exists?(:materials,
+                    :file_suppressed_by_user_id,
+                    name: 'index_materials_on_file_suppressed_by_user_id')
+      remove_index :materials, name: 'index_materials_on_file_suppressed_by_user_id'
+    end
+
+    remove_column :materials, :file_suppressed_at if column_exists?(
+        :materials,
+        :file_suppressed_at)
+    remove_column :materials, :file_suppressed_by_user_id if column_exists?(
+        :materials,
+        :file_suppressed_by_user_id)
+    remove_column :materials, :file_suppression_reason if column_exists?(
+        :materials,
+        :file_suppression_reason)
+  end
+
+  def remove_material_version_file_suppression!
+    remove_column :material_versions, :file_suppressed_at if column_exists?(
+        :material_versions,
+        :file_suppressed_at)
+    remove_column :material_versions, :file_suppression_reason if column_exists?(
+        :material_versions,
+        :file_suppression_reason)
+  end
+
+  def reconcile_material_version_event_constraint!
+    constraint = check_constraints(:material_versions).find do |candidate|
+      candidate.name == MATERIAL_VERSION_EVENT_CONSTRAINT
+    end
+    return if constraint && !constraint.expression.include?('suppress')
+
+    if constraint
+      remove_check_constraint :material_versions, name: MATERIAL_VERSION_EVENT_CONSTRAINT
+    end
+    add_check_constraint :material_versions,
+                         "event_type IN ('create', 'update', 'discard', 'restore')",
+                         name: MATERIAL_VERSION_EVENT_CONSTRAINT
+  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_23_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_06_25_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
@@ -72,7 +72,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.index ["correct_post_id"], name: "index_gekanator_games_on_correct_post_id"
     t.index ["guessed_post_id"], name: "index_gekanator_games_on_guessed_post_id"
     t.index ["user_id"], name: "index_gekanator_games_on_user_id"
-    t.check_constraint "`question_count` >= 0", name: "chk_gekanator_games_question_count_nonnegative"
   end
 
   create_table "gekanator_question_examples", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -156,6 +155,22 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.index ["created_by_user_id"], name: "index_material_import_blocks_on_created_by_user_id"
   end
 
+  create_table "material_sync_suppressions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.string "source_kind", null: false
+    t.string "source_uri"
+    t.string "drive_path"
+    t.string "drive_file_id"
+    t.string "normalized_source_key", null: false
+    t.string "reason", 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_sync_suppressions_on_created_by_user_id"
+    t.index ["drive_file_id"], name: "index_material_sync_suppressions_on_drive_file_id"
+    t.index ["normalized_source_key"], name: "index_material_sync_suppressions_on_normalized_source_key", unique: true
+    t.index ["source_kind"], name: "index_material_sync_suppressions_on_source_kind"
+  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
@@ -177,8 +192,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     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"
@@ -188,7 +201,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     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"
+    t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore')", name: "material_versions_event_type_valid"
   end
 
   create_table "materials", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -202,13 +215,16 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     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.string "source_kind"
+    t.string "source_uri"
+    t.string "source_path"
+    t.string "source_file_id"
+    t.string "normalized_source_key"
+    t.virtual "active_normalized_source_key", type: :string, as: "if((`discarded_at` is null),`normalized_source_key`,NULL)"
+    t.index ["active_normalized_source_key"], name: "index_materials_on_active_normalized_source_key", unique: true
     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"
@@ -232,10 +248,9 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.datetime "created_at", null: false
     t.bigint "created_by_user_id"
     t.index ["created_at"], name: "index_nico_tag_versions_on_created_at"
-    t.index ["created_by_user_id", "created_at"], name: "index_nico_tag_versions_on_created_by_user_id_and_created_at", order: { created_at: :desc }
-    t.index ["tag_id", "created_at"], name: "index_nico_tag_versions_on_tag_id_and_created_at", order: { created_at: :desc }
+    t.index ["created_by_user_id", "created_at"], name: "index_nico_tag_versions_on_created_by_user_id_and_created_at"
+    t.index ["tag_id", "created_at"], name: "index_nico_tag_versions_on_tag_id_and_created_at"
     t.index ["tag_id", "version_no"], name: "index_nico_tag_versions_on_tag_id_and_version_no", unique: true
-    t.check_constraint "`version_no` > 0", name: "nico_tag_versions_version_no_positive"
   end
 
   create_table "post_implications", primary_key: ["post_id", "parent_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -244,14 +259,13 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["parent_post_id"], name: "index_post_implications_on_parent_post_id"
-    t.check_constraint "`post_id` <> `parent_post_id`", name: "chk_post_implications_no_self"
   end
 
   create_table "post_similarities", primary_key: ["post_id", "target_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "target_post_id", null: false
     t.float "cos", null: false
-    t.index ["post_id", "cos"], name: "index_post_similarities_on_post_id_and_cos", order: { cos: :desc }
+    t.index ["post_id", "cos"], name: "index_post_similarities_on_post_id_and_cos"
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
@@ -291,8 +305,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.index ["created_by_user_id"], name: "index_post_versions_on_created_by_user_id"
     t.index ["post_id", "version_no"], name: "index_post_versions_on_post_id_and_version_no", unique: true
     t.index ["post_id"], name: "index_post_versions_on_post_id"
-    t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore')", name: "post_versions_event_type_valid"
-    t.check_constraint "`version_no` > 0", name: "post_versions_version_no_positive"
   end
 
   create_table "posts", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -307,7 +319,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.integer "version_no", null: false
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
-    t.check_constraint "`version_no` > 0", name: "chk_posts_version_no_positive"
   end
 
   create_table "settings", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -354,7 +365,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.bigint "tag_id", null: false
     t.bigint "target_tag_id", null: false
     t.float "cos", null: false
-    t.index ["tag_id", "cos"], name: "index_tag_similarities_on_tag_id_and_cos", order: { cos: :desc }
+    t.index ["tag_id", "cos"], name: "index_tag_similarities_on_tag_id_and_cos"
     t.index ["target_tag_id"], name: "index_tag_similarities_on_target_tag_id"
   end
 
@@ -364,32 +375,30 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_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 "deprecated_at"
     t.datetime "created_at", null: false
     t.bigint "created_by_user_id"
     t.index ["created_at"], name: "index_tag_versions_on_created_at"
-    t.index ["created_by_user_id", "created_at"], name: "index_tag_versions_on_created_by_user_id_and_created_at", order: { created_at: :desc }
-    t.index ["tag_id", "created_at"], name: "index_tag_versions_on_tag_id_and_created_at", order: { created_at: :desc }
+    t.index ["created_by_user_id", "created_at"], name: "index_tag_versions_on_created_by_user_id_and_created_at"
+    t.index ["tag_id", "created_at"], name: "index_tag_versions_on_tag_id_and_created_at"
     t.index ["tag_id", "version_no"], name: "index_tag_versions_on_tag_id_and_version_no", unique: true
-    t.check_constraint "`version_no` > 0", name: "tag_versions_version_no_positive"
   end
 
   create_table "tags", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "tag_name_id", null: false
     t.string "category", default: "general", null: false
+    t.datetime "deprecated_at"
     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
 
   create_table "theatre_comments", primary_key: ["theatre_id", "no"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -514,19 +523,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.index ["banned_at"], name: "index_users_on_banned_at"
   end
 
-  create_table "wiki_assets", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "wiki_page_id", null: false
-    t.integer "no", null: false
-    t.string "alt_text"
-    t.binary "sha256", limit: 32, null: false
-    t.bigint "created_by_user_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["created_by_user_id"], name: "index_wiki_assets_on_created_by_user_id"
-    t.index ["wiki_page_id", "no"], name: "index_wiki_assets_on_wiki_page_id_and_no", unique: true
-    t.index ["wiki_page_id", "sha256"], name: "index_wiki_assets_on_wiki_page_id_and_sha256", unique: true
-  end
-
   create_table "wiki_lines", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "sha256", limit: 64, null: false
     t.text "body", null: false
@@ -543,13 +539,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.datetime "discarded_at"
-    t.integer "next_asset_no", default: 1, null: false
     t.integer "version_no", null: false
     t.index ["created_user_id"], name: "index_wiki_pages_on_created_user_id"
     t.index ["discarded_at"], name: "index_wiki_pages_on_discarded_at"
     t.index ["tag_name_id"], name: "index_wiki_pages_on_tag_name_id", unique: true
     t.index ["updated_user_id"], name: "index_wiki_pages_on_updated_user_id"
-    t.check_constraint "`version_no` > 0", name: "chk_wiki_pages_version_no_positive"
   end
 
   create_table "wiki_revision_lines", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -594,8 +588,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
     t.index ["created_by_user_id"], name: "index_wiki_versions_on_created_by_user_id"
     t.index ["wiki_page_id", "version_no"], name: "index_wiki_versions_on_wiki_page_id_and_version_no", unique: true
     t.index ["wiki_page_id"], name: "index_wiki_versions_on_wiki_page_id"
-    t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore')", name: "wiki_versions_event_type_valid"
-    t.check_constraint "`version_no` > 0", name: "wiki_versions_version_no_positive"
   end
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
@@ -615,6 +607,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
   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_sync_suppressions", "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"
@@ -623,7 +616,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_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"
@@ -672,8 +664,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_23_000000) do
   add_foreign_key "user_ips", "users"
   add_foreign_key "user_post_views", "posts"
   add_foreign_key "user_post_views", "users"
-  add_foreign_key "wiki_assets", "users", column: "created_by_user_id"
-  add_foreign_key "wiki_assets", "wiki_pages"
   add_foreign_key "wiki_pages", "tag_names"
   add_foreign_key "wiki_pages", "users", column: "created_user_id"
   add_foreign_key "wiki_pages", "users", column: "updated_user_id"

frontend/src/App.tsx

@@ -16,6 +16,7 @@ import MaterialBasePage from '@/pages/materials/MaterialBasePage'
 import MaterialDetailPage from '@/pages/materials/MaterialDetailPage'
 import MaterialListPage from '@/pages/materials/MaterialListPage'
 import MaterialNewPage from '@/pages/materials/MaterialNewPage'
+import MaterialSyncSuppressionsPage from '@/pages/materials/MaterialSyncSuppressionsPage'
 // import MaterialSearchPage from '@/pages/materials/MaterialSearchPage'
 import MorePage from '@/pages/MorePage'
 import GekanatorPage from '@/pages/GekanatorPage'
@@ -69,7 +70,8 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/materials" element={<MaterialBasePage/>}>
 	    <Route index element={<MaterialListPage/>}/>
 	    <Route path="new" element={<MaterialNewPage/>}/>
-	    <Route path=":id" element ={<MaterialDetailPage user={user}/>}/>
+	    <Route path="suppressions" element={<MaterialSyncSuppressionsPage/>}/>
+	    <Route path=":id" element ={<MaterialDetailPage/>}/>
 	  </Route>
 	  {/* <Route path="/materials/search" element={<MaterialSearchPage/>}/> */}
 	  <Route path="/wiki" element={<WikiSearchPage/>}/>

frontend/src/lib/materials.ts

@@ -1,7 +1,6 @@
 import {
     apiGet,
     isApiError,
-    apiPatch,
     apiPost,
     apiPut,
 } from '@/lib/api'
@@ -10,6 +9,7 @@ import type {
     Material,
     FetchMaterialsParams,
     MaterialFilter,
+    MaterialSyncSuppression,
     MaterialSidebarTag,
     MaterialTagTree,
 } from '@/types'
@@ -24,6 +24,10 @@ export type MaterialIndexResponse = {
     count:     number
 }
 
+export type MaterialSyncSuppressionResponse = {
+    suppressions: MaterialSyncSuppression[]
+}
+
 const MATERIAL_FILTERS: MaterialFilter[] = ['present', 'missing', 'any']
 
 
@@ -36,13 +40,13 @@ export const parseMaterialFilter = (
 
 
 export const fetchMaterials = async (
-    { q, tagState, mediaKind, suppression, createdFrom, createdTo,
-      updatedFrom, updatedTo, sort, direction, page, limit }: FetchMaterialsParams): Promise<MaterialIndexResponse> =>
+    { q, tagState, mediaKind, createdFrom, createdTo,
+      updatedFrom, updatedTo, sort, direction, page,
+      limit }: FetchMaterialsParams): Promise<MaterialIndexResponse> =>
     await apiGet ('/materials', { params: {
 	...(q && { q }),
 	tag_state:   tagState,
 	media_kind:  mediaKind,
-	suppression,
 	...(createdFrom && { created_from: createdFrom }),
 	...(createdTo && { created_to: createdTo }),
 	...(updatedFrom && { updated_from: updatedFrom }),
@@ -101,7 +105,22 @@ export const updateMaterial = async (
     await apiPut (`/materials/${ id }`, formData)
 
 
-export const suppressMaterialFile = async (
-    id: string,
-    payload: { reason: string; purge?: boolean }): Promise<Material> =>
-    await apiPatch (`/materials/${ id }/suppress_file`, payload)
+export const fetchMaterialSyncSuppressions =
+    async (): Promise<MaterialSyncSuppressionResponse> =>
+        await apiGet ('/materials/suppressions')
+
+
+export const createMaterialSyncSuppression = async (
+    payload: {
+        sourceKind:   string
+        sourceUri?:   string
+        drivePath?:   string
+        driveFileId?: string
+        reason:       string
+    }): Promise<MaterialSyncSuppression> =>
+    await apiPost ('/materials/suppressions', {
+        source_kind:   payload.sourceKind,
+        source_uri:    payload.sourceUri,
+        drive_path:    payload.drivePath,
+        drive_file_id: payload.driveFileId,
+        reason:        payload.reason})

frontend/src/lib/queryKeys.ts

@@ -37,6 +37,7 @@ export const materialsKeys = {
     byTagName:     (name: string, materialFilter: MaterialFilter) =>
 		      ['materials', 'tag', name, materialFilter] as const,
     show:         (id: string) => ['materials', id] as const,
+    suppressions: () => ['materials', 'suppressions'] as const,
     tree:         (p: {
 	parentId?:       number | null
 	materialFilter:  MaterialFilter

frontend/src/pages/materials/MaterialDetailPage.tsx

@@ -15,7 +15,6 @@ import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
 import {
-    suppressMaterialFile,
     fetchMaterial,
     updateMaterial,
 } from '@/lib/materials'
@@ -25,12 +24,10 @@ import { useValidationErrors } from '@/lib/useValidationErrors'
 
 import type { FC } from 'react'
 
-import type { User } from '@/types'
-
 type MaterialFormField = 'tag' | 'file' | 'url' | 'exportPaths'
 
 
-const MaterialDetailPage: FC<{ user: User | null }> = ({ user }) => {
+const MaterialDetailPage: FC = () => {
   const { id } = useParams ()
   const qc = useQueryClient ()
 
@@ -91,35 +88,11 @@ const MaterialDetailPage: FC<{ user: User | null }> = ({ user }) => {
 	toast ({ title: '更新失敗……', description: '入力を見直してください．' })
       }})
 
-  const suppressMutation = useMutation ({
-      mutationFn: async (reason: string) =>
-	  await suppressMaterialFile (id ?? '', { reason }),
-      onSuccess: async data => {
-	qc.setQueryData (materialsKeys.show (id ?? ''), data)
-	setFile (null)
-	setFilePreview ('')
-	await invalidateMaterialQueries ()
-	toast ({ title: '抑止しました' })
-      },
-      onError: () => {
-	toast ({ title: '抑止に失敗しました' })
-      }})
-
   const handleSubmit = () => {
     clearValidationErrors ()
     updateMutation.mutate ()
   }
 
-  const handleSuppress = () => {
-    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
-
-    suppressMutation.mutate (reason)
-  }
-
   return (
       <MainArea>
 	{material && (
@@ -145,16 +118,7 @@ const MaterialDetailPage: FC<{ user: User | null }> = ({ user }) => {
 		 : materialTitle}
 	      </PageTitle>
 
-	      {material.fileSuppressedAt && (
-		  <div className="mb-4 rounded border border-red-300 bg-red-50 p-3
-				  text-red-900 dark:border-red-800 dark:bg-red-950
-				  dark:text-red-100">
-		    <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) && (
+	      {(material.file && material.contentType) && (
 		  (/image\/.*/.test (material.contentType) && (
 		      <img src={material.file} alt={material.tag?.name || undefined}/>))
 		  || (/video\/.*/.test (material.contentType) && (
@@ -256,14 +220,6 @@ const MaterialDetailPage: FC<{ user: User | null }> = ({ user }) => {
 			  disabled={updateMutation.isPending}>
 			更新
 		      </Button>
-		      {user?.role === 'admin' && !material.fileSuppressedAt && (
-			  <Button
-			      type="button"
-			      variant="destructive"
-			      onClick={handleSuppress}
-			      disabled={suppressMutation.isPending}>
-			    ファイルを抑止
-			  </Button>)}
 		    </div>
 		  </div>
 		</Tab>

frontend/src/pages/materials/MaterialListPage.tsx

@@ -23,7 +23,6 @@ import type {
     MaterialIndexDirection,
     MaterialIndexMediaKind,
     MaterialIndexSort,
-    MaterialIndexSuppression,
     MaterialIndexTagState,
     MaterialIndexView } from '@/types'
 
@@ -32,8 +31,7 @@ const MEDIA_KIND_LABELS: Record<Material['mediaKind'], string> = {
     video:      '動画',
     audio:      '音声',
     file_other: 'その他ファイル',
-    url_only:   'URL のみ',
-    suppressed: '抑止済み'}
+    url_only:   'URL のみ'}
 
 const MEDIA_FILTER_LABELS: Record<MaterialIndexMediaKind, string> = {
     all:        'すべて',
@@ -84,14 +82,9 @@ const materialTitle = (material: Material): string =>
 const MaterialThumb: FC<{ material: Material }> = ({ material }) => (
     <div
 	className={`flex aspect-square h-[180px] w-[180px] items-center justify-center
-		    overflow-hidden rounded-lg border text-center shadow-sm ${
-		    material.fileSuppressedAt
-		    ? [
-			'border-red-300 bg-red-50 text-red-900 dark:border-red-800',
-			'dark:bg-red-950 dark:text-red-100'].join (' ')
-		    : [
-			'border-stone-200 bg-white text-stone-900 dark:border-stone-700',
-			'dark:bg-stone-900 dark:text-stone-100'].join (' ') }`}>
+		    overflow-hidden rounded-lg border border-stone-200 bg-white text-center
+		    text-stone-900 shadow-sm dark:border-stone-700 dark:bg-stone-900
+		    dark:text-stone-100`}>
       {material.thumbnail
        ? <img src={material.thumbnail} alt="" className="h-full w-full object-contain"/>
        : (
@@ -123,14 +116,8 @@ const MaterialCard: FC<{ material: Material }> = ({ material }) => (
 
 const MaterialListItem: FC<{ material: Material }> = ({ material }) => (
     <article
-	className={`rounded-lg border p-3 shadow-sm ${
-		    material.fileSuppressedAt
-		    ? [
-			'border-red-200 bg-red-50 text-red-900 dark:border-red-900',
-			'dark:bg-red-950 dark:text-red-100'].join (' ')
-		    : [
-			'border-stone-200 bg-white text-stone-900 dark:border-stone-700',
-			'dark:bg-stone-900 dark:text-stone-100'].join (' ')}`}>
+	className="rounded-lg border border-stone-200 bg-white p-3 text-stone-900
+		   shadow-sm dark:border-stone-700 dark:bg-stone-900 dark:text-stone-100">
       <div className="flex gap-3">
 	<MaterialThumb material={material}/>
 	<div className="min-w-0 flex-1 space-y-2">
@@ -141,8 +128,6 @@ const MaterialListItem: FC<{ material: Material }> = ({ material }) => (
 			   dark:text-sky-300">
 	      {materialTitle (material)}
 	    </PrefetchLink>
-	    {material.fileSuppressedAt && (
-		<p className="mt-1 text-sm text-red-700 dark:text-red-200">抑止済み</p>)}
 	  </div>
 	  <dl className="space-y-1 text-sm text-stone-600 dark:text-stone-300">
 	    <div>
@@ -188,10 +173,6 @@ const MaterialListPage: FC = () => {
       query.get ('media_kind'),
       ['all', 'image', 'video', 'audio', 'file_other', 'url_only'],
       'all')
-  const suppression = parseOption<MaterialIndexSuppression> (
-      query.get ('suppression'),
-      ['active', 'suppressed', 'all'],
-      'active')
   const sort = parseOption<MaterialIndexSort> (
       query.get ('sort'),
       ['created_at', 'updated_at', 'tag_name', 'media_kind', 'file_byte_size',
@@ -210,8 +191,6 @@ const MaterialListPage: FC = () => {
   const [q, setQ] = useState ('')
   const [tagStateInput, setTagStateInput] = useState<MaterialIndexTagState> ('all')
   const [mediaKindInput, setMediaKindInput] = useState<MaterialIndexMediaKind> ('all')
-  const [suppressionInput, setSuppressionInput] =
-      useState<MaterialIndexSuppression> ('active')
   const [createdFrom, setCreatedFrom] = useState<string | null> (null)
   const [createdTo, setCreatedTo] = useState<string | null> (null)
   const [updatedFrom, setUpdatedFrom] = useState<string | null> (null)
@@ -221,7 +200,6 @@ const MaterialListPage: FC = () => {
       q: qQuery,
       tagState,
       mediaKind,
-      suppression,
       createdFrom: createdFromQuery,
       createdTo: createdToQuery,
       updatedFrom: updatedFromQuery,
@@ -241,12 +219,11 @@ const MaterialListPage: FC = () => {
     setQ (qQuery)
     setTagStateInput (tagState)
     setMediaKindInput (mediaKind)
-    setSuppressionInput (suppression)
     setCreatedFrom (createdFromQuery)
     setCreatedTo (createdToQuery)
     setUpdatedFrom (updatedFromQuery)
     setUpdatedTo (updatedToQuery)
-  }, [createdFromQuery, createdToQuery, mediaKind, qQuery, suppression, tagState,
+  }, [createdFromQuery, createdToQuery, mediaKind, qQuery, tagState,
       updatedFromQuery, updatedToQuery])
 
   const search = (e: FormEvent) => {
@@ -256,7 +233,6 @@ const MaterialListPage: FC = () => {
     setIf (qs, 'q', q)
     qs.set ('tag_state', tagStateInput)
     qs.set ('media_kind', mediaKindInput)
-    qs.set ('suppression', suppressionInput)
     setIf (qs, 'created_from', createdFrom)
     setIf (qs, 'created_to', createdTo)
     setIf (qs, 'updated_from', updatedFrom)
@@ -301,6 +277,13 @@ const MaterialListPage: FC = () => {
 			     dark:bg-stone-900 dark:text-stone-100 dark:hover:bg-stone-800">
 		新規素材を追加
 	      </PrefetchLink>
+	      <PrefetchLink
+		  to="/materials/suppressions"
+		  className="rounded-full border border-stone-300 bg-white px-4 py-2 text-sm
+			     text-stone-900 hover:bg-stone-100 dark:border-stone-700
+			     dark:bg-stone-900 dark:text-stone-100 dark:hover:bg-stone-800">
+		同期元抑止
+	      </PrefetchLink>
 	      <a
 		  href={`${ API_BASE_URL }/materials/download.zip?profile=legacy_drive`}
 		  target="_blank"
@@ -363,19 +346,6 @@ const MaterialListPage: FC = () => {
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="抑止状態">
-		{({ invalid }) => (
-		    <select
-			value={suppressionInput}
-			onChange={e => setSuppressionInput (
-			    e.target.value as MaterialIndexSuppression)}
-			className={inputClass (invalid)}>
-		      <option value="active">有効のみ</option>
-		      <option value="suppressed">抑止済みのみ</option>
-		      <option value="all">すべて</option>
-		    </select>)}
-	      </FormField>
-
 	      <FormField label="作成日時">
 		{() => (
 		    <div className="flex flex-wrap items-center gap-2">

frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx

@@ -0,0 +1,194 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
+import { useState } from 'react'
+import { Helmet } from 'react-helmet-async'
+
+import PrefetchLink from '@/components/PrefetchLink'
+import FormField from '@/components/common/FormField'
+import PageTitle from '@/components/common/PageTitle'
+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 {
+    createMaterialSyncSuppression,
+    fetchMaterialSyncSuppressions,
+} from '@/lib/materials'
+import { materialsKeys } from '@/lib/queryKeys'
+import { dateString, inputClass } from '@/lib/utils'
+
+import type { FC, FormEvent } from 'react'
+
+import type { MaterialSyncSuppressionSourceKind } from '@/types'
+
+const SOURCE_KIND_LABELS: Record<MaterialSyncSuppressionSourceKind, string> = {
+    uri:               'URI',
+    google_drive_path: 'Google Drive path',
+    google_drive_file: 'Google Drive file ID',
+    legacy_drive_path: 'Legacy Drive path'}
+
+const REASONS = [
+    'copyright_high_risk',
+    'copyright_takedown',
+    'adult_or_sensitive',
+    'personal_information',
+    'malware_or_dangerous_file',
+    'duplicate_or_low_quality',
+    'source_owner_request',
+    'other']
+
+
+const MaterialSyncSuppressionsPage: FC = () => {
+  const qc = useQueryClient ()
+  const [sourceKind, setSourceKind] =
+      useState<MaterialSyncSuppressionSourceKind> ('uri')
+  const [sourceUri, setSourceUri] = useState ('')
+  const [drivePath, setDrivePath] = useState ('')
+  const [driveFileId, setDriveFileId] = useState ('')
+  const [reason, setReason] = useState (REASONS[0])
+
+  const { data, isError, isLoading } = useQuery ({
+      queryKey: materialsKeys.suppressions (),
+      queryFn:  fetchMaterialSyncSuppressions})
+
+  const createMutation = useMutation ({
+      mutationFn: async () =>
+	  await createMaterialSyncSuppression ({
+	      sourceKind,
+	      sourceUri,
+	      drivePath,
+	      driveFileId,
+	      reason}),
+      onSuccess: async () => {
+	await qc.invalidateQueries ({ queryKey: materialsKeys.suppressions () })
+	await qc.invalidateQueries ({ queryKey: materialsKeys.root })
+	setSourceUri ('')
+	setDrivePath ('')
+	setDriveFileId ('')
+	toast ({ title: '同期元抑止を登録しました' })
+      },
+      onError: () => {
+	toast ({ title: '同期元抑止の登録に失敗しました' })
+      }})
+
+  const handleSubmit = (event: FormEvent) => {
+    event.preventDefault ()
+    createMutation.mutate ()
+  }
+
+  const suppressions = data?.suppressions ?? []
+
+  return (
+      <MainArea>
+	<Helmet>
+	  <title>{`同期元抑止 | ${ SITE_TITLE }`}</title>
+	</Helmet>
+
+	<div className="space-y-5">
+	  <div className="flex flex-wrap items-center justify-between gap-3">
+	    <PageTitle>同期元抑止</PageTitle>
+	    <PrefetchLink
+		to="/materials"
+		className="text-sm text-sky-700 underline underline-offset-2 dark:text-sky-300">
+	      素材一覧へ戻る
+	    </PrefetchLink>
+	  </div>
+
+	  <form
+	      onSubmit={handleSubmit}
+	      className="max-w-3xl rounded-lg border border-stone-200 bg-white p-4
+			 text-stone-900 dark:border-stone-700 dark:bg-stone-900
+			 dark:text-stone-100">
+	    <div className="space-y-3">
+	      <FormField label="同期元種別">
+		{({ invalid }) => (
+		    <select
+			value={sourceKind}
+			onChange={e => setSourceKind (
+			    e.target.value as MaterialSyncSuppressionSourceKind)}
+			className={inputClass (invalid)}>
+		      {Object.entries (SOURCE_KIND_LABELS).map (([value, label]) => (
+			  <option key={value} value={value}>
+			    {label}
+			  </option>))}
+		    </select>)}
+	      </FormField>
+
+	      <FormField label="Source URI">
+		{({ invalid }) => (
+		    <input
+			type="text"
+			value={sourceUri}
+			onChange={e => setSourceUri (e.target.value)}
+			className={inputClass (invalid)}/>)}
+	      </FormField>
+
+	      <FormField label="Drive path">
+		{({ invalid }) => (
+		    <input
+			type="text"
+			value={drivePath}
+			onChange={e => setDrivePath (e.target.value)}
+			className={inputClass (invalid)}/>)}
+	      </FormField>
+
+	      <FormField label="Drive file ID">
+		{({ invalid }) => (
+		    <input
+			type="text"
+			value={driveFileId}
+			onChange={e => setDriveFileId (e.target.value)}
+			className={inputClass (invalid)}/>)}
+	      </FormField>
+
+	      <FormField label="理由">
+		{({ invalid }) => (
+		    <select
+			value={reason}
+			onChange={e => setReason (e.target.value)}
+			className={inputClass (invalid)}>
+		      {REASONS.map (value => (
+			  <option key={value} value={value}>
+			    {value}
+			  </option>))}
+		    </select>)}
+	      </FormField>
+	    </div>
+
+	    <Button
+		type="submit"
+		className="mt-4 rounded bg-blue-600 px-4 py-2 text-white
+			   disabled:bg-gray-400"
+		disabled={createMutation.isPending}>
+	      登録
+	    </Button>
+	  </form>
+
+	  {isLoading && <p>Loading...</p>}
+	  {isError && (
+	      <p className="text-red-600 dark:text-red-300">
+		同期元抑止一覧の取得に失敗しました．
+	      </p>)}
+
+	  <div className="space-y-3">
+	    {suppressions.map (suppression => (
+		<article
+		    key={suppression.id}
+		    className="rounded-lg border border-stone-200 bg-white p-3
+			       text-stone-900 shadow-sm dark:border-stone-700
+			       dark:bg-stone-900 dark:text-stone-100">
+		  <div className="font-medium">
+		    {SOURCE_KIND_LABELS[suppression.sourceKind]}
+		  </div>
+		  <div className="break-all text-sm text-stone-700 dark:text-stone-300">
+		    {suppression.normalizedSourceKey}
+		  </div>
+		  <div className="mt-2 text-sm text-stone-600 dark:text-stone-400">
+		    理由: {suppression.reason} / 登録: {dateString (suppression.createdAt)}
+		  </div>
+		</article>))}
+	  </div>
+	</div>
+      </MainArea>)
+}
+
+export default MaterialSyncSuppressionsPage

frontend/src/test/factories.ts

@@ -76,6 +76,11 @@ export const buildMaterial = (overrides: Partial<Material> = {}): Material => ({
   tag:                   buildTag (),
   file:                  null,
   url:                   null,
+  sourceKind:            null,
+  sourceUri:             null,
+  sourcePath:            null,
+  sourceFileId:          null,
+  normalizedSourceKey:   null,
   wikiPageBody:          null,
   thumbnail:             null,
   thumbnailFallbackText: 'テストタグ',
@@ -83,8 +88,6 @@ export const buildMaterial = (overrides: Partial<Material> = {}): Material => ({
   mediaKind:             'url_only',
   contentType:           null,
   fileByteSize:          null,
-  fileSuppressedAt:      null,
-  fileSuppressionReason: null,
   exportPaths:           {},
   exportItems:           [],
   createdAt:             '2026-01-02T03:04:05.000Z',

frontend/src/types.ts

@@ -86,8 +86,6 @@ export type MaterialIndexSort =
     | 'version_no'
     | 'id'
 
-export type MaterialIndexSuppression = 'active' | 'suppressed' | 'all'
-
 export type MaterialIndexTagState = 'all' | 'tagged' | 'untagged'
 
 export type MaterialIndexView = 'card' | 'list'
@@ -96,7 +94,6 @@ export type FetchMaterialsParams = {
     q:            string
     tagState:     MaterialIndexTagState
     mediaKind:    MaterialIndexMediaKind
-    suppression:  MaterialIndexSuppression
     createdFrom:  string
     createdTo:    string
     updatedFrom:  string
@@ -113,15 +110,18 @@ export type Material = {
     tag:                    Tag | null
     file:                   string | null
     url:                    string | null
+    sourceKind:             string | null
+    sourceUri:              string | null
+    sourcePath:             string | null
+    sourceFileId:           string | null
+    normalizedSourceKey:    string | null
     wikiPageBody?:          string | null
     thumbnail:              string | null
     thumbnailFallbackText:  string | null
     thumbnailFallbackKind:  'tag_name' | 'created_at'
-    mediaKind:              'image' | 'video' | 'audio' | 'file_other' | 'url_only' | 'suppressed'
+    mediaKind:              'image' | 'video' | 'audio' | 'file_other' | 'url_only'
     contentType:            string | null
     fileByteSize:           number | null
-    fileSuppressedAt:       string | null
-    fileSuppressionReason:  string | null
     exportPaths:            Record<string, string>
     exportItems:            MaterialExportItem[]
     createdAt:              string
@@ -129,6 +129,24 @@ export type Material = {
     updatedAt:              string
     updatedByUser:          { id: number; name: string } }
 
+export type MaterialSyncSuppressionSourceKind =
+    | 'uri'
+    | 'google_drive_path'
+    | 'google_drive_file'
+    | 'legacy_drive_path'
+
+export type MaterialSyncSuppression = {
+    id:                  number
+    sourceKind:          MaterialSyncSuppressionSourceKind
+    sourceUri:           string | null
+    drivePath:           string | null
+    driveFileId:         string | null
+    normalizedSourceKey: string
+    reason:              string
+    createdByUser:       { id: number; name: string } | null
+    createdAt:           string
+    updatedAt:           string }
+
 export type MaterialSidebarTag = {
     id:          number
     name:        string