#306

AGENTS.md

@@ -271,7 +271,12 @@ const value =
 - In TypeScript and TSX, convert every leading run of 8 spaces to a tab
   character.
 - A leading tab is exactly equivalent to 8 leading spaces.
-- Never place a closing parenthesis at the beginning of a line.
+- In TypeScript and TSX function declarations, including `const` arrow
+  function declarations, when the parameter list spans multiple lines, always
+  put the closing parenthesis at the beginning of its own line before the return
+  type or `=>`.
+- In TypeScript and TSX, never place a closing parenthesis at the beginning of
+  a line except for a multi-line function declaration parameter list.
 - Never place a closing square bracket at the beginning of a line.
 - For object literals and other associative-array-style braces, do not place
   the closing brace at the beginning of a line. Function, lambda, callback, and

backend/app/controllers/materials_controller.rb

@@ -523,10 +523,7 @@ class MaterialsController < ApplicationController
         content_type: file.content_type,
     )
 
-    if file_sha256.present?
-      blob.metadata['sha256'] = file_sha256
-      blob.save! if blob.changed?
-    end
+    MaterialFileSha256.assign_metadata_sha256!(blob, file_sha256)
 
     blob
   ensure

backend/app/models/material.rb

@@ -1,6 +1,9 @@
 class Material < ApplicationRecord
   include MyDiscard
 
+  SOURCE_KINDS = ['uri', 'google_drive_path', 'google_drive_file',
+                  'legacy_drive_path'].freeze
+
   default_scope -> { kept }
 
   belongs_to :parent, class_name: 'Material', optional: true
@@ -20,7 +23,7 @@ class Material < ApplicationRecord
 
   validates :tag_id, uniqueness: true, allow_nil: true
   validates :source_kind,
-            inclusion: { in: MaterialSyncSuppression::SOURCE_KINDS },
+            inclusion: { in: SOURCE_KINDS },
             allow_blank: true
 
   validate :file_must_be_attached

backend/app/services/google_drive/api_client.rb

@@ -26,13 +26,19 @@ module GoogleDrive
 
     def list_material_files_under_folder folder_id
       files = []
+      each_material_file_under_folder(folder_id) { |entry| files << entry }
+      files
+    end
+
+    def each_material_file_under_folder folder_id
+      return enum_for(__method__, folder_id) unless block_given?
+
       walk_folder(folder_id, nil) do |entry, relative_path|
         next if entry['mimeType'] == FOLDER_MIME_TYPE
         next if native_file?(entry['mimeType'])
 
-        files << build_file_entry(entry, relative_path)
+        yield build_file_entry(entry, relative_path)
       end
-      files
     end
 
     def fetch_material_file file_id
@@ -44,9 +50,10 @@ module GoogleDrive
 
     def download_to_tempfile file_id, filename:
       tempfile = Tempfile.new(['material-sync', File.extname(filename.to_s)])
+      tempfile.binmode
       request_binary("/files/#{ file_id }",
                      { alt: 'media', supportsAllDrives: true }) do |chunk|
-        tempfile.write(chunk)
+        tempfile.write(chunk.b)
       end
       tempfile.rewind
       tempfile
@@ -139,7 +146,7 @@ module GoogleDrive
         end
 
         response.read_body do |chunk|
-          yield chunk
+          yield chunk.b
         end
       end
     end

backend/app/services/material_file_sha256.rb

@@ -1,16 +1,39 @@
 require 'digest'
+require 'json'
 
 class MaterialFileSha256
+  def self.blob_metadata blob
+    metadata = blob.metadata
+    return metadata if metadata.is_a?(Hash)
+    return { } if metadata.blank?
+
+    JSON.parse(metadata)
+  rescue JSON::ParserError
+    { }
+  end
+
+  def self.metadata_sha256 blob
+    blob_metadata(blob)['sha256'].presence
+  end
+
+  def self.assign_metadata_sha256! blob, sha256
+    return if sha256.blank?
+
+    metadata = blob_metadata(blob)
+    metadata['sha256'] = sha256
+    blob.metadata = metadata
+    blob.save! if blob.changed?
+  end
+
   def self.from_blob blob, allow_download: false
-    sha256 = blob.metadata['sha256']
+    sha256 = metadata_sha256(blob)
     return sha256 if sha256.present?
     return nil unless allow_download
 
     begin
       blob.open do |file|
         sha256 = Digest::SHA256.file(file.path).hexdigest
-        blob.metadata['sha256'] = sha256
-        blob.save! if blob.changed?
+        assign_metadata_sha256!(blob, sha256)
         sha256
       end
     rescue ActiveStorage::FileNotFoundError, ArgumentError => error

backend/app/services/material_sync_importer.rb

@@ -148,8 +148,7 @@ class MaterialSyncImporter
         io: tempfile,
         filename: @attributes[:filename],
         content_type: @attributes[:content_type])
-    blob.metadata['sha256'] = file_sha256 if file_sha256.present?
-    blob.save! if blob.changed?
+    MaterialFileSha256.assign_metadata_sha256!(blob, file_sha256)
     tempfile.rewind
     blob
   end
@@ -226,7 +225,7 @@ class MaterialSyncImporter
     if expected_sha256.present?
       return false unless material.file.attached?
 
-      return material.file.blob.metadata['sha256'] == expected_sha256
+      return MaterialFileSha256.metadata_sha256(material.file.blob) == expected_sha256
     end
 
     !material.file.attached?

backend/app/services/material_sync_runner.rb

@@ -21,10 +21,14 @@ class MaterialSyncRunner
     result = Result.new(imported: 0, updated: 0, unchanged: 0,
                         suppressed: 0, failed: 0, errors: [])
 
-    candidates.each do |candidate|
-      next if candidate.blank?
+    if @source.source_kind == 'google_drive_path'
+      sync_google_drive_path!(result)
+    else
+      candidates.each do |candidate|
+        next if candidate.blank?
 
-      sync_candidate!(candidate, result)
+        sync_candidate!(candidate, result)
+      end
     end
 
     @source.update!(last_synced_at: Time.current)
@@ -43,8 +47,6 @@ class MaterialSyncRunner
     case @source.source_kind
     when 'uri'
       [uri_candidate]
-    when 'google_drive_path'
-      google_drive_path_candidates
     when 'google_drive_file'
       [google_drive_file_candidate]
     when 'legacy_drive_path'
@@ -104,12 +106,25 @@ class MaterialSyncRunner
   def google_drive_path_candidates
     folder_id = google_drive_folder_id
     Enumerator.new do |entries|
-      drive_client.list_material_files_under_folder(folder_id).each do |entry|
+      drive_client.each_material_file_under_folder(folder_id).each do |entry|
         entries << build_google_drive_candidate(entry)
       end
     end
   end
 
+  def sync_google_drive_path! result
+    folder_id = google_drive_folder_id
+    scanned_count = 0
+
+    drive_client.each_material_file_under_folder(folder_id) do |entry|
+      scanned_count += 1
+      sync_candidate!(build_google_drive_candidate(entry), result)
+      log_google_drive_progress(folder_id, scanned_count, result) if progress_log_scan_count?(scanned_count)
+    end
+
+    log_google_drive_progress(folder_id, scanned_count, result, summary: true)
+  end
+
   def google_drive_file_candidate
     entry = drive_client.fetch_material_file(google_drive_file_id)
     return nil unless entry
@@ -213,6 +228,22 @@ class MaterialSyncRunner
                                         failed: result.failed))
   end
 
+  def progress_log_scan_count? scanned_count
+    scanned_count == 1 || (scanned_count % 50).zero?
+  end
+
+  def log_google_drive_progress folder_id, scanned_count, result, summary: false
+    Rails.logger.info(
+        material_sync_log(folder_id:,
+                          scanned_count:,
+                          imported: result.imported,
+                          updated: result.updated,
+                          unchanged: result.unchanged,
+                          suppressed: result.suppressed,
+                          failed: result.failed,
+                          progress: summary ? 'summary' : 'scan'))
+  end
+
   def material_sync_log fields
     { material_sync_source_id: @source.id,
       material_sync_source_name: @source.name }.merge(fields).to_json

backend/app/services/material_version_recorder.rb

@@ -57,7 +57,7 @@ class MaterialVersionRecorder < VersionRecorder
       file_content_type: blob.content_type,
       file_byte_size: blob.byte_size,
       file_checksum: blob.checksum,
-      file_sha256: blob.metadata['sha256'] }
+      file_sha256: MaterialFileSha256.metadata_sha256(blob) }
   end
 
   def empty_file_snapshot

backend/db/schema.rb

@@ -72,6 +72,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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|
@@ -274,9 +275,10 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"
-    t.index ["tag_id", "created_at"], name: "index_nico_tag_versions_on_tag_id_and_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 ["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|
@@ -285,13 +287,14 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"
+    t.index ["post_id", "cos"], name: "index_post_similarities_on_post_id_and_cos", order: { cos: :desc }
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
@@ -331,6 +334,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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|
@@ -345,6 +350,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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|
@@ -391,7 +397,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"
+    t.index ["tag_id", "cos"], name: "index_tag_similarities_on_tag_id_and_cos", order: { cos: :desc }
     t.index ["target_tag_id"], name: "index_tag_similarities_on_target_tag_id"
   end
 
@@ -401,30 +407,32 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"
-    t.index ["tag_id", "created_at"], name: "index_tag_versions_on_tag_id_and_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 ["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|
@@ -549,6 +557,19 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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
@@ -565,11 +586,13 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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|
@@ -614,6 +637,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"
@@ -692,6 +717,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_26_010000) 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"

backend/spec/models/material_spec.rb

@@ -0,0 +1,19 @@
+require 'rails_helper'
+
+RSpec.describe Material, type: :model do
+  let(:user) { create(:user, :member) }
+
+  it 'allows only material source kinds, not suppression prefix kinds' do
+    material = described_class.new(url: 'https://example.com/material',
+                                   source_kind: 'google_drive_path_prefix',
+                                   source_path: '素材/危険',
+                                   created_by_user: user,
+                                   updated_by_user: user)
+
+    expect(material).not_to be_valid
+    expect(material.errors[:source_kind]).to be_present
+
+    material.source_kind = 'google_drive_path'
+    expect(material).to be_valid
+  end
+end

backend/spec/requests/materials_spec.rb

@@ -113,6 +113,68 @@ RSpec.describe 'Materials API', type: :request do
       expect(response_materials.size).to eq(1)
       expect(response_materials.first['id']).to eq(material_b.id)
     end
+
+    it 'filters by descendant tags and returns stable parent tag groups' do
+      root =
+          Tag.create!(tag_name: TagName.create!(name: 'material_scope_root'),
+                      category: :material)
+      child_b =
+          Tag.create!(tag_name: TagName.create!(name: 'material_scope_b'),
+                      category: :material)
+      child_a =
+          Tag.create!(tag_name: TagName.create!(name: 'material_scope_a'),
+                      category: :material)
+      deprecated =
+          Tag.create!(tag_name: TagName.create!(name: 'material_scope_old'),
+                      category: :material,
+                      deprecated_at: Time.current)
+      grandchild =
+          Tag.create!(tag_name: TagName.create!(name: 'material_scope_grandchild'),
+                      category: :material)
+      root_material =
+          build_material(tag: root, user: member_user,
+                         file: dummy_upload(filename: 'root.png'))
+      child_a_material =
+          build_material(tag: child_a, user: member_user,
+                         file: dummy_upload(filename: 'child_a.png'))
+      grandchild_material =
+          build_material(tag: grandchild, user: member_user,
+                         file: dummy_upload(filename: 'grandchild.png'))
+
+      TagImplication.create!(parent_tag: root, tag: child_b)
+      TagImplication.create!(parent_tag: root, tag: child_a)
+      TagImplication.create!(parent_tag: child_b, tag: deprecated)
+      TagImplication.create!(parent_tag: deprecated, tag: grandchild)
+
+      get '/materials',
+          params: { tag_id: root.id, include_descendants: '1',
+                    group_by: 'parent_tag', sort: 'id', direction: 'asc' }
+
+      expect(response).to have_http_status(:ok)
+      expect(response_materials.map { |m| m['id'] })
+        .to include(root_material.id, child_a_material.id, grandchild_material.id)
+      expect(json['tag_scope']).to eq(
+        'tag' => {
+          'id' => root.id,
+          'name' => 'material_scope_root',
+          'category' => 'material'
+        },
+        'include_descendants' => true
+      )
+      expect(json['groups'].map { |group| group.dig('tag', 'name') })
+        .to eq(['material_scope_a', 'material_scope_b', 'material_scope_root'])
+      expect(json['groups'].find { |group| group.dig('tag', 'id') == child_b.id }
+        .fetch('material_ids')).to eq([grandchild_material.id])
+    end
+
+    it 'returns nil tag_scope when tag_id is unknown' do
+      get '/materials', params: { tag_id: 999_999, group_by: 'parent_tag' }
+
+      expect(response).to have_http_status(:ok)
+      expect(json['tag_scope']).to be_nil
+      expect(json['groups']).to eq([])
+      expect(response_materials).to eq([])
+    end
   end
 
   describe 'GET /materials/:id' do

backend/spec/services/material_file_sha256_spec.rb

@@ -0,0 +1,23 @@
+require 'rails_helper'
+
+RSpec.describe MaterialFileSha256 do
+  describe '.metadata_sha256' do
+    it 'reads sha256 from Hash metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: { 'sha256' => 'abc123' })
+
+      expect(described_class.metadata_sha256(blob)).to eq('abc123')
+    end
+
+    it 'reads sha256 from JSON string metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: '{"sha256":"abc123"}')
+
+      expect(described_class.metadata_sha256(blob)).to eq('abc123')
+    end
+
+    it 'returns nil for invalid metadata' do
+      blob = instance_double(ActiveStorage::Blob, metadata: '{')
+
+      expect(described_class.metadata_sha256(blob)).to be_nil
+    end
+  end
+end

backend/spec/services/material_sync_runner_spec.rb

@@ -0,0 +1,89 @@
+require 'rails_helper'
+
+RSpec.describe MaterialSyncRunner do
+  let(:user) { create(:user, :member) }
+  let(:source) do
+    MaterialSyncSource.create!(
+        name: 'Drive source',
+        source_kind: 'google_drive_path',
+        source_file_id: 'folder-123',
+        profile: 'legacy_drive',
+        created_by_user: user,
+        updated_by_user: user)
+  end
+  let(:drive_client) { instance_double(GoogleDrive::ApiClient) }
+
+  describe '#sync!' do
+    it 'imports google drive path candidates as they are yielded' do
+      first_entry = { id: 'file-1',
+                      name: 'a.png',
+                      mime_type: 'image/png',
+                      relative_path: '素材/a.png',
+                      sha256_checksum: 'sha-a',
+                      web_view_link: 'https://drive.google.com/file/d/file-1/view',
+                      web_content_link: nil }
+      second_entry = { id: 'file-2',
+                       name: 'b.png',
+                       mime_type: 'image/png',
+                       relative_path: '素材/b.png',
+                       sha256_checksum: 'sha-b',
+                       web_view_link: 'https://drive.google.com/file/d/file-2/view',
+                       web_content_link: nil }
+      yielded = []
+
+      allow(GoogleDrive::ApiClient).to receive(:new).and_return(drive_client)
+      allow(drive_client).to receive(:each_material_file_under_folder) do |folder_id, &block|
+        expect(folder_id).to eq('folder-123')
+        block.call(first_entry)
+        expect(yielded).to eq(['素材/a.png'])
+        block.call(second_entry)
+      end
+      allow(MaterialSyncImporter).to receive(:import!) do |candidate|
+        yielded << candidate.fetch(:source_path)
+        instance_double(MaterialSyncImporter::Result,
+                        action: yielded.last == '素材/a.png' ? :imported : :updated)
+      end
+
+      result = described_class.new(source).sync!
+
+      expect(yielded).to eq(['素材/a.png', '素材/b.png'])
+      expect(result.imported).to eq(1)
+      expect(result.updated).to eq(1)
+      expect(result.unchanged).to eq(0)
+      expect(source.reload.last_synced_at).to be_present
+    end
+
+    it 'logs google drive path progress at first item and summary' do
+      entry = { id: 'file-1',
+                name: 'a.png',
+                mime_type: 'image/png',
+                relative_path: '素材/a.png',
+                sha256_checksum: 'sha-a',
+                web_view_link: 'https://drive.google.com/file/d/file-1/view',
+                web_content_link: nil }
+      logged = []
+
+      allow(GoogleDrive::ApiClient).to receive(:new).and_return(drive_client)
+      allow(drive_client).to receive(:each_material_file_under_folder) do |_folder_id, &block|
+        block.call(entry)
+      end
+      allow(MaterialSyncImporter).to receive(:import!)
+        .and_return(instance_double(MaterialSyncImporter::Result, action: :imported))
+      allow(Rails.logger).to receive(:info) { |message| logged << JSON.parse(message) }
+
+      described_class.new(source).sync!
+
+      progress_logs = logged.select { |row| row['folder_id'] == 'folder-123' }
+      expect(progress_logs.map { |row| row['progress'] }).to eq(['scan', 'summary'])
+      expect(progress_logs.last).to include(
+          'material_sync_source_id' => source.id,
+          'material_sync_source_name' => 'Drive source',
+          'scanned_count' => 1,
+          'imported' => 1,
+          'updated' => 0,
+          'unchanged' => 0,
+          'suppressed' => 0,
+          'failed' => 0)
+    end
+  end
+end

frontend/src/App.tsx

@@ -75,7 +75,6 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	    <Route path="suppressions" element={<MaterialSyncSuppressionsPage/>}/>
 	    <Route path=":id" element ={<MaterialDetailPage/>}/>
 	  </Route>
-	  {/* <Route path="/materials/search" element={<MaterialSearchPage/>}/> */}
 	  <Route path="/wiki" element={<WikiSearchPage/>}/>
 	  <Route path="/wiki/:title" element={<WikiDetailPage/>}/>
 	  <Route path="/wiki/new" element={<WikiNewPage user={user}/>}/>

frontend/src/components/MaterialSidebar.tsx

@@ -1,29 +1,43 @@
-import { Fragment, useEffect, useRef, useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
+import { useEffect, useRef, useState } from 'react'
 import { useLocation, useNavigate } from 'react-router-dom'
 
-import PrefetchLink from '@/components/PrefetchLink'
-import TagLink from '@/components/TagLink'
 import SidebarComponent from '@/components/layout/SidebarComponent'
-import { materialsKeys } from '@/lib/queryKeys'
+import TagLink from '@/components/TagLink'
 import { fetchMaterialTagTree, parseMaterialFilter } from '@/lib/materials'
+import { materialsKeys } from '@/lib/queryKeys'
+import { cn } from '@/lib/utils'
 
-import type { Dispatch, FC, ReactNode, SetStateAction } from 'react'
+import type { CSSProperties, Dispatch, FC, ReactNode, SetStateAction } from 'react'
 
 import type { MaterialFilter, MaterialSidebarTag, Tag } from '@/types'
 
-const FILTERS: MaterialFilter[] = ['present', 'missing', 'any']
+const FILTERS: MaterialFilter[] = ['missing', 'present', 'any']
+const FILTER_LABELS: Record<MaterialFilter, string> = { present: '有', missing: '無', any: '全' }
 
-const FILTER_LABELS: Record<MaterialFilter, string> = {
-    present: '素材あり',
-    missing: '素材なし',
-    any:     'すべて'}
+
+const px = (value: string): number => {
+  const parsed = Number.parseFloat (value)
+  return Number.isFinite (parsed) ? parsed : 0
+}
+
+
+const verticalChrome = (el: HTMLElement): number => {
+  const style = window.getComputedStyle (el)
+
+  return (
+      px (style.paddingTop)
+      + px (style.paddingBottom)
+      + px (style.borderTopWidth)
+      + px (style.borderBottomWidth))
+}
 
 
 const setChildrenById = (
     tags:     MaterialSidebarTag[],
     targetId: number,
-    children: MaterialSidebarTag[]): MaterialSidebarTag[] => (
+    children: MaterialSidebarTag[],
+): MaterialSidebarTag[] => (
     tags.map (tag => {
       if (tag.id === targetId)
 	return { ...tag, children }
@@ -37,24 +51,12 @@ const setChildrenById = (
 
 const materialPath = (
     tagId: number,
-    materialFilter: MaterialFilter): string =>
+    materialFilter: MaterialFilter,
+): string =>
     `/materials?tag_id=${ tagId }&include_descendants=1&group_by=parent_tag`
     + `&material_filter=${ materialFilter }`
 
 
-const clearTagSelectionPath = (
-    locationSearch: string,
-    materialFilter: MaterialFilter): string => {
-    const qs = new URLSearchParams (locationSearch)
-    qs.delete ('tag_id')
-    qs.delete ('include_descendants')
-    qs.delete ('group_by')
-    qs.delete ('page')
-    qs.set ('material_filter', materialFilter)
-    return `/materials?${ qs.toString () }`
-}
-
-
 const sidebarTagToTag = (tag: MaterialSidebarTag): Tag => ({
     id:             tag.id,
     name:           tag.name,
@@ -72,39 +74,42 @@ const sidebarTagToTag = (tag: MaterialSidebarTag): Tag => ({
 
 
 const tagSelectionShellClass = (selected: boolean): string =>
-    selected
-    ? 'rounded-md border border-sky-500 bg-sky-50 px-2 py-1 text-sky-700 '
-      + 'dark:border-sky-400 dark:bg-sky-950 dark:text-sky-100'
-    : 'px-2 py-1'
+    cn (selected
+	? ['rounded-md border border-sky-500 bg-sky-50 px-2 py-1 text-sky-700',
+	   'dark:border-sky-400 dark:bg-sky-950 dark:text-sky-100']
+	: 'px-2 py-1')
 
 
 const updateMaterialFilterQuery = (
     pathname: string,
     locationSearch: string,
     navigate: ReturnType<typeof useNavigate>,
-    materialFilter: MaterialFilter) => {
-    const qs = new URLSearchParams (locationSearch)
-    qs.set ('material_filter', materialFilter)
-    navigate (`${ pathname }${ qs.toString () ? `?${ qs.toString () }` : '' }`)
+    materialFilter: MaterialFilter,
+) => {
+  const qs = new URLSearchParams (locationSearch)
+  qs.set ('material_filter', materialFilter)
+  navigate (`${ pathname }${ qs.toString () ? `?${ qs.toString () }` : '' }`)
 }
 
 
-const MaterialFilterButtons: FC<{
-    materialFilter: MaterialFilter
-    onChange:       (materialFilter: MaterialFilter) => void
-}> = ({ materialFilter, onChange }) => (
-    <div className="flex flex-wrap gap-2">
+const MaterialFilterButtons: FC<{ materialFilter: MaterialFilter
+				  onChange:       (materialFilter: MaterialFilter) => void }> = (
+    { materialFilter, onChange },
+) => (
+    <div className="flex flex-wrap gap-2 justify-end md:justify-start flex-center">
+      <label className="my-auto text-sm font-bold">素材：</label>
       {FILTERS.map (value => (
-      <button
+	  <button
 	      key={value}
 	      type="button"
 	      onClick={() => onChange (value)}
-	      className={`rounded-full border px-3 py-1 text-sm ${
-		  materialFilter === value
-		  ? 'border-sky-500 bg-sky-50 text-sky-700 dark:border-sky-400 '
-		    + 'dark:bg-sky-950 dark:text-sky-100'
-		  : 'border-neutral-300 bg-white text-neutral-700 dark:border-stone-700 '
-		    + 'dark:bg-stone-900 dark:text-stone-200' }`}>
+	      className={cn (
+		  'rounded-full border px-3 py-1 text-sm',
+		  (materialFilter === value
+		   ? ['border-sky-500 bg-sky-50 text-sky-700 dark:border-sky-400',
+		      'dark:bg-sky-950 dark:text-sky-100']
+		   : ['border-neutral-300 bg-white text-neutral-700 dark:border-stone-700',
+		      'dark:bg-stone-900 dark:text-stone-200']))}>
 	    {FILTER_LABELS[value]}
 	  </button>))}
     </div>)
@@ -132,10 +137,10 @@ const MaterialTreeNode: FC<{
   }, [data, onChildren, open, tag.children.length, tag.id])
 
   return (
-      <Fragment>
+      <>
 	<li>
-	  <div className="flex">
-	    <div className="flex-none w-4">
+	  <div className="flex flex-center">
+	    <div className="flex-none w-4 my-auto">
 	      {tag.hasChildren && (
 		  <button
 		      type="button"
@@ -144,8 +149,9 @@ const MaterialTreeNode: FC<{
 		    {open ? <>&minus;</> : '+'}
 		  </button>)}
 	    </div>
-	    <div className="flex-1 truncate">
-	      <div className={tagSelectionShellClass (selectedTagId === tag.id)}>
+	    <div className="min-w-0 flex-1 my-auto">
+	      <div className={cn (tagSelectionShellClass (selectedTagId === tag.id),
+				  'min-w-0 truncate')}>
 		<TagLink
 		    tag={sidebarTagToTag (tag)}
 		    nestLevel={nestLevel}
@@ -160,7 +166,7 @@ const MaterialTreeNode: FC<{
 	{open && tag.children.length > 0 && (
 	    <ul>
 	      {tag.children.map (child => (
-		      <MaterialTreeNode
+		  <MaterialTreeNode
 		      key={child.id}
 		      tag={child}
 		      nestLevel={nestLevel + 1}
@@ -170,21 +176,39 @@ const MaterialTreeNode: FC<{
 		      setOpenTags={setOpenTags}
 		      onChildren={onChildren}/>))}
 	    </ul>)}
-      </Fragment>)
+      </>)
 }
 
 
-const MobileMaterialTreeNode: FC<{
-    depth?:          number
-    materialFilter: MaterialFilter
-    selectedTagId:  number | null
-    onChildren:     (tagId: number, children: MaterialSidebarTag[]) => void
-    openTags:       Record<number, boolean>
-    setOpenTags:    Dispatch<SetStateAction<Record<number, boolean>>>
-    tag:            MaterialSidebarTag
-}> = ({ depth = 0, materialFilter, onChildren, openTags, selectedTagId,
-	 setOpenTags, tag }) => {
+const MobileMaterialTreeNode: FC<{ depth?: number
+				   availableInlineSizePx?: number | null
+				   materialFilter: MaterialFilter
+				   selectedTagId: number | null
+				   onChildren: (tagId: number, children: MaterialSidebarTag[]) =>
+						   void
+				   openTags: Record<number, boolean>
+				   setOpenTags: Dispatch<SetStateAction<Record<number, boolean>>>
+				   tag: MaterialSidebarTag }> = (
+    {
+      depth = 0,
+      availableInlineSizePx = null,
+      materialFilter,
+      onChildren,
+      openTags,
+      selectedTagId,
+      setOpenTags,
+      tag,
+    },
+) => {
   const open = Boolean (openTags[tag.id])
+  const tagColumnRef = useRef<HTMLDivElement | null> (null)
+  const chipRef = useRef<HTMLDivElement | null> (null)
+  const buttonRef = useRef<HTMLButtonElement | null> (null)
+  const expansionSlotRef = useRef<HTMLDivElement | null> (null)
+  const expansionBorderRef = useRef<HTMLDivElement | null> (null)
+  const [tagChipInlineSizePx, setTagChipInlineSizePx] = useState<number | null> (null)
+  const [tagLinkInlineSizePx, setTagLinkInlineSizePx] = useState<number | null> (null)
+  const [childAvailableInlineSizePx, setChildAvailableInlineSizePx] = useState<number | null> (null)
   const { data } = useQuery ({
       queryKey: materialsKeys.tree ({ parentId: tag.id, materialFilter }),
       queryFn:  () => fetchMaterialTagTree ({ parentId: tag.id, materialFilter }),
@@ -195,50 +219,155 @@ const MobileMaterialTreeNode: FC<{
       onChildren (tag.id, data)
   }, [data, onChildren, open, tag.children.length, tag.id])
 
+  useEffect (() => {
+    const tagColumn = tagColumnRef.current
+    const chip = chipRef.current
+    if (!(tagColumn) || !(chip))
+      return
+
+    const updateTagInlineSize = () => {
+      const buttonHeight = buttonRef.current?.offsetHeight ?? 0
+      const gap = tag.hasChildren ? px (window.getComputedStyle (tagColumn).rowGap) : 0
+      const columnHeight =
+	  availableInlineSizePx == null
+	  ? tagColumn.clientHeight
+	  : Math.min (tagColumn.clientHeight, availableInlineSizePx)
+      const nextChipInlineSize = Math.max (24, columnHeight - buttonHeight - gap)
+      const nextLinkInlineSize = Math.max (
+	  16,
+	  nextChipInlineSize - verticalChrome (chip),
+      )
+
+      setTagChipInlineSizePx (prev => prev === nextChipInlineSize ? prev : nextChipInlineSize)
+      setTagLinkInlineSizePx (prev => prev === nextLinkInlineSize ? prev : nextLinkInlineSize)
+    }
+
+    updateTagInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateTagInlineSize ()
+    })
+
+    resizeObserver.observe (tagColumn)
+    resizeObserver.observe (chip)
+
+    if (buttonRef.current)
+      resizeObserver.observe (buttonRef.current)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [availableInlineSizePx, open, tag.hasChildren, tag.children.length])
+
+  useEffect (() => {
+    const expansionSlot = expansionSlotRef.current
+    const expansionBorder = expansionBorderRef.current
+    if (!(expansionSlot) || !(expansionBorder))
+      return
+
+    const updateChildInlineSize = () => {
+      const base =
+	  availableInlineSizePx == null
+	  ? expansionSlot.clientHeight
+	  : availableInlineSizePx
+      const chrome = verticalChrome (expansionSlot) + verticalChrome (expansionBorder)
+      const nextInlineSize = Math.max (24, base - chrome)
+      setChildAvailableInlineSizePx (prev => prev === nextInlineSize ? prev : nextInlineSize)
+    }
+
+    updateChildInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateChildInlineSize ()
+    })
+
+    resizeObserver.observe (expansionSlot)
+    resizeObserver.observe (expansionBorder)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [availableInlineSizePx, open, tag.children.length])
+
   return (
-      <div className="flex flex-row-reverse items-start gap-2">
-      <div className="flex flex-col items-center gap-1">
+      <div className="flex h-full min-h-0 max-h-full flex-row-reverse items-start gap-2
+		      overflow-hidden">
+	<div
+	    ref={tagColumnRef}
+	    className="flex h-full min-h-0 max-h-full flex-col items-center gap-1
+		       overflow-hidden">
 	  <div
-	      className={`${ tagSelectionShellClass (selectedTagId === tag.id) } rounded-xl
-			 border px-3 py-2 text-sm shadow-sm`}
-	      style={{ writingMode: 'vertical-rl' }}>
+	      ref={chipRef}
+	      className={cn (
+		  tagSelectionShellClass (selectedTagId === tag.id),
+		  'box-border rounded-xl border px-3 py-2 text-sm shadow-sm',
+		  'min-h-0 overflow-hidden [max-inline-size:var(--tag-chip-inline-size)]',
+		  '[max-height:var(--tag-chip-inline-size)]',
+	      )}
+	      style={{
+		writingMode: 'vertical-rl',
+		'--tag-chip-inline-size': (
+		    tagChipInlineSizePx == null
+		    ? undefined
+		    : `${ tagChipInlineSizePx }px`),
+		'--tag-link-inline-size': (
+		    tagLinkInlineSizePx == null
+		    ? undefined
+		    : `${ tagLinkInlineSizePx }px`),
+	      } as CSSProperties}>
 	    <TagLink
 		tag={sidebarTagToTag (tag)}
 		title={tag.name}
 		withCount={false}
 		withWiki={false}
-		to={materialPath (tag.id, materialFilter)}/>
+		to={materialPath (tag.id, materialFilter)}
+		className="block overflow-hidden text-ellipsis whitespace-nowrap
+			   [max-inline-size:var(--tag-link-inline-size)]
+			   [max-height:var(--tag-link-inline-size)]"/>
 	  </div>
 	  {tag.hasChildren && (
 	      <button
+		  ref={buttonRef}
 		  type="button"
 		  onClick={() => setOpenTags (prev => ({ ...prev, [tag.id]: !prev[tag.id] }))}
-		  className="rounded-full border border-stone-300 bg-white px-2 py-0.5
-			     text-sm text-stone-700 dark:border-stone-700
+		  className="flex-none rounded-full border border-stone-300 bg-white
+			     px-2 py-0.5 text-sm text-stone-700 dark:border-stone-700
 			     dark:bg-stone-900 dark:text-stone-100">
 		{open ? <>&minus;</> : '+'}
 	      </button>)}
 	</div>
 	{open && tag.children.length > 0 && (
 	    <div
-		className="relative flex flex-row-reverse items-start gap-2 rounded-2xl border
-			   border-stone-200 bg-stone-100/70 py-2 pl-2 pr-2 text-stone-900
-			   dark:border-stone-700 dark:bg-stone-900/70 dark:text-stone-100"
-		style={{ marginTop: `${ depth === 0 ? 1.25 : .75 }rem` }}>
-	      <span
-		  aria-hidden="true"
-		  className="absolute -right-3 top-4 h-px w-3 bg-stone-300 dark:bg-stone-600"/>
-	      {tag.children.map (child => (
-		  <div key={child.id} className="relative">
-	    <MobileMaterialTreeNode
-		      tag={child}
-		      depth={depth + 1}
-		      materialFilter={materialFilter}
-		      selectedTagId={selectedTagId}
-		      openTags={openTags}
-		      setOpenTags={setOpenTags}
-		      onChildren={onChildren}/>
-		  </div>))}
+		ref={expansionSlotRef}
+		className={cn (
+		    'h-full min-h-0 max-h-full overflow-hidden box-border',
+		    depth === 0 ? 'pt-5' : 'pt-3')}>
+	      <div
+		  ref={expansionBorderRef}
+		  className="relative max-h-full overflow-hidden rounded-2xl border border-stone-200
+			     bg-stone-100/70 py-2 pl-2 pr-2 text-stone-900
+			     dark:border-stone-700 dark:bg-stone-900/70 dark:text-stone-100">
+		<div className="flex h-full min-h-0 max-h-full flex-row-reverse items-start gap-2
+				overflow-hidden">
+		  <span
+		      aria-hidden="true"
+		      className="absolute -right-3 top-4 h-px w-3 bg-stone-300 dark:bg-stone-600"/>
+		  {tag.children.map (child => (
+		      <div
+			  key={child.id}
+			  className="relative h-full min-h-0 max-h-full overflow-hidden">
+			<MobileMaterialTreeNode
+			    tag={child}
+			    depth={depth + 1}
+			    availableInlineSizePx={childAvailableInlineSizePx}
+			    materialFilter={materialFilter}
+			    selectedTagId={selectedTagId}
+			    openTags={openTags}
+			    setOpenTags={setOpenTags}
+			    onChildren={onChildren}/>
+		      </div>))}
+		</div>
+	      </div>
 	    </div>)}
       </div>)
 }
@@ -248,12 +377,14 @@ const MaterialSidebar: FC = () => {
   const location = useLocation ()
   const navigate = useNavigate ()
   const qs = new URLSearchParams (location.search)
-  const materialFilter = parseMaterialFilter (qs.get ('material_filter'), 'present')
+  const materialFilter = parseMaterialFilter (qs.get ('material_filter'), 'any')
   const selectedTagId = Number (qs.get ('tag_id') ?? 0) || null
 
   const [desktopTags, setDesktopTags] = useState<MaterialSidebarTag[]> ([])
   const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
   const mobileRailRef = useRef<HTMLDivElement | null> (null)
+  const [mobileAvailableInlineSizePx, setMobileAvailableInlineSizePx] =
+      useState<number | null> (null)
 
   const { data: rootTags = [], isLoading, isError } = useQuery ({
       queryKey: materialsKeys.tree ({ parentId: null, materialFilter }),
@@ -273,6 +404,29 @@ const MaterialSidebar: FC = () => {
     })
   }, [rootTags, materialFilter])
 
+  useEffect (() => {
+    const el = mobileRailRef.current
+    if (!(el))
+      return
+
+    const updateAvailableInlineSize = () => {
+      const nextInlineSize = Math.max (24, el.clientHeight)
+      setMobileAvailableInlineSizePx (prev => prev === nextInlineSize ? prev : nextInlineSize)
+    }
+
+    updateAvailableInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateAvailableInlineSize ()
+    })
+
+    resizeObserver.observe (el)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [rootTags, materialFilter])
+
   const visibleRootTags = desktopTags.length > 0 ? desktopTags : rootTags
 
   const setChildren = (tagId: number, children: MaterialSidebarTag[]) => {
@@ -288,8 +442,6 @@ const MaterialSidebar: FC = () => {
     updateMaterialFilterQuery (location.pathname, location.search, navigate, value)
   }
 
-  const clearTagSelection = clearTagSelectionPath (location.search, materialFilter)
-
   const renderDesktopTree = (tags: MaterialSidebarTag[]): ReactNode => (
       tags.map (tag => (
 	  <MaterialTreeNode
@@ -304,24 +456,21 @@ const MaterialSidebar: FC = () => {
   return (
       <>
 	<div className="border-b bg-stone-50 p-3 dark:border-stone-700 dark:bg-stone-950
-			dark:text-stone-100 md:hidden">
-	  <div className="mb-3">
-	    <PrefetchLink
-		to={clearTagSelection}
-		className="text-sm text-sky-700 underline underline-offset-2
-			   dark:text-sky-300">
-	      {selectedTagId != null ? '選択解除' : '全素材'}
-	    </PrefetchLink>
-	  </div>
+			dark:text-stone-100 md:hidden flex h-[25dvh] min-h-0 flex-col
+			overflow-hidden">
 	  <MaterialFilterButtons
 	      materialFilter={materialFilter}
 	      onChange={handleFilterChange}/>
-	  <div ref={mobileRailRef} className="mt-3 overflow-x-auto">
-	    <div className="flex min-w-max flex-row-reverse gap-3 pb-1">
+	  <div
+	      ref={mobileRailRef}
+	      className="mt-3 min-h-0 flex-1 overflow-x-auto overflow-y-hidden">
+	    <div className="flex min-w-max flex-row-reverse items-start gap-3 pb-1 h-full
+			    min-h-0 max-h-full">
 	      {visibleRootTags.map (tag => (
 		  <MobileMaterialTreeNode
 		      key={tag.id}
 		      tag={tag}
+		      availableInlineSizePx={mobileAvailableInlineSizePx}
 		      materialFilter={materialFilter}
 		      selectedTagId={selectedTagId}
 		      openTags={openTags}
@@ -334,12 +483,6 @@ const MaterialSidebar: FC = () => {
 	<div className="hidden md:block">
 	  <SidebarComponent>
 	    <div className="space-y-4">
-	      <PrefetchLink
-		  to={clearTagSelection}
-		  className="text-sm text-sky-700 underline underline-offset-2
-			     dark:text-sky-300">
-		{selectedTagId != null ? '選択解除' : '全素材'}
-	      </PrefetchLink>
 	      <MaterialFilterButtons
 		  materialFilter={materialFilter}
 		  onChange={handleFilterChange}/>

frontend/src/components/TagLink.tsx

@@ -28,11 +28,12 @@ type Props =
 
 
 const TagLink: FC<Props> = ({ tag,
-		   nestLevel = 0,
-		   linkFlg   = true,
-		   withWiki  = true,
-		   withCount = true,
-		   ...props }) => {
+			      nestLevel = 0,
+			      linkFlg   = true,
+			      withWiki  = true,
+			      withCount = true,
+			      className,
+			      ...props }) => {
   const spanClass = cn (
       `text-${ TAG_COLOUR[tag.category] }-${ LIGHT_COLOUR_SHADE }`,
       `dark:text-${ TAG_COLOUR[tag.category] }-${ DARK_COLOUR_SHADE }`)
@@ -105,7 +106,7 @@ const TagLink: FC<Props> = ({ tag,
 	    </span>)}
 	{tag.matchedAlias != null && (
 	    <>
-	      <span className={spanClass} {...props}>
+	      <span className={cn (spanClass, className)} {...props}>
 		{tag.matchedAlias}
 	      </span>
 	      <> → </>
@@ -114,12 +115,12 @@ const TagLink: FC<Props> = ({ tag,
 	 ? (
 	    <PrefetchLink
 		to={`/posts?${ (new URLSearchParams ({ tags: tag.name })).toString () }`}
-		className={linkClass}
+		className={cn (linkClass, className)}
 		{...props}>
 	      {tag.name}
 	    </PrefetchLink>)
 	 : (
-	    <span className={spanClass}
+	    <span className={cn (spanClass, className)}
 		  {...props}>
 	      {tag.name}
 	    </span>)}

frontend/src/components/TopNav.tsx

@@ -7,30 +7,36 @@ import Separator from '@/components/MenuSeparator'
 import PrefetchLink from '@/components/PrefetchLink'
 import TopNavUser from '@/components/TopNavUser'
 import { WikiIdBus } from '@/lib/eventBus/WikiIdBus'
-import { tagsKeys, wikiKeys } from '@/lib/queryKeys'
+import { materialsKeys, tagsKeys, wikiKeys } from '@/lib/queryKeys'
 import { fetchTag, fetchTagByName } from '@/lib/tags'
+import { fetchMaterial } from '@/lib/materials'
 import { cn } from '@/lib/utils'
 import { fetchWikiPage } from '@/lib/wiki'
 
 import type { FC, MouseEvent } from 'react'
 
-import type { Menu, MenuVisibleItem, Tag, User } from '@/types'
+import type { Material, Menu, MenuVisibleItem, Tag, User } from '@/types'
 
 type Props = { user: User | null }
 
 
-export const menuOutline = ({ tag, wikiId, user, pathName }: { 
-    tag?: Tag | null
-    wikiId: number | null
-    user: User | null,
-    pathName: string }): Menu => {
-  const postCount = tag?.postCount ?? 0
+export const menuOutline = (
+    { tag, material, wikiId, user, pathName }: {
+	tag?: Tag | null
+	material?: Material | null
+	wikiId: number | null
+	user: User | null,
+	pathName: string },
+): Menu => {
+  const postCount = tag?.postCount ?? material?.tag?.postCount ?? 0
 
   const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^/]+/.test (pathName) && wikiId)
   const wikiTitle = pathName.split ('/')[2] ?? ''
 
   const tagFlg = /^\/tags\/\d+/.test (pathName)
 
+  const materialFlg = /^\/materials\/\d+/.test (pathName)
+
   return [
       { name: '広場', to: '/posts', subMenu: [
 	  { name: '一覧', to: '/posts' },
@@ -49,12 +55,18 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 	    visible: tagFlg },
 	  { name: '履歴', to: `/tags/changes?id=${ tag?.id }`,
 	    visible: tagFlg && tag?.category !== 'nico' }] },
-      { name: '素材', to: '/materials', visible: false, subMenu: [
+      { name: '素材', to: '/materials', visible: true, subMenu: [
 	  { name: '一覧', to: '/materials' },
-	  { name: '検索', to: '/materials/search', visible: false }, 
 	  { name: '追加', to: '/materials/new' },
-	  { name: '全体履歴', to: '/materials/changes', visible: false },
-	  { name: 'ヘルプ', to: '/wiki/ヘルプ:素材集' }] },
+	  { name: '抑止', to: '/materials/suppressions' },
+	  { name: '全体履歴', to: '/materials/changes' },
+	  { name: 'ヘルプ', to: '/wiki/ヘルプ:素材管理' },
+	  { component: <Separator/>, visible: materialFlg },
+	  { name: `広場 (${ postCount || 0 })`,
+	    to: `/posts?tags=${ encodeURIComponent (material?.tag?.name ?? '') }`,
+	    visible: materialFlg && Boolean (material?.tag) },
+	  { name: '履歴', to: `/materials/changes?material_id=${ material?.id }`,
+	    visible: materialFlg }] },
       { name: 'Wiki', to: '/wiki/ヘルプ:ホーム', base: '/wiki', subMenu: [
 	  { name: '検索', to: '/wiki' },
 	  { name: '新規', to: '/wiki/new' },
@@ -119,15 +131,23 @@ const TopNav: FC<Props> = ({ user }) => {
       queryFn: () => fetchWikiPage (wikiIdStr, { }) })
 
   const tagFlg = /^\/tags\/\d+/.test (location.pathname)
-  const effectiveTitle = (tagFlg ? location.pathname.split ('/')[2] : wikiPage?.title) ?? ''
+  const materialFlg = /^\/materials\/\d+/.test (location.pathname)
+  const effectiveTitle = (((tagFlg || materialFlg)
+			   ? location.pathname.split ('/')[2]
+			   : wikiPage?.title)
+			  ?? '')
 
   const { data: tag } = useQuery ({
       enabled: Boolean (effectiveTitle),
       queryKey: tagsKeys.show (effectiveTitle),
       queryFn: () => (tagFlg ? fetchTag : fetchTagByName) (effectiveTitle) })
 
+  const { data: material } = useQuery ({
+      enabled: Boolean (effectiveTitle),
+      queryKey: materialsKeys.show (effectiveTitle),
+      queryFn: () => fetchMaterial (effectiveTitle) })
 
-  const menu = menuOutline ({ tag, wikiId, user, pathName: location.pathname })
+  const menu = menuOutline ({ tag, material, wikiId, user, pathName: location.pathname })
   const visibleMenu = menu.filter ((item): item is MenuVisibleItem => item.visible ?? true)
   const moreMenu = menu.filter (item =>
       !(item.visible ?? true)

frontend/src/components/common/PageTitle.tsx

@@ -1,12 +1,14 @@
 import React from 'react'
 
+import { cn } from '@/lib/utils'
+
 import type { FC } from 'react'
 
-type Props = { children: React.ReactNode }
+type Props = { children: React.ReactNode; className?: string }
 
 
-const PageTitle: FC<Props> = ({ children }) => (
-    <h1 className="text-2xl font-bold mb-2">
+const PageTitle: FC<Props> = ({ children, className, ...rest }) => (
+    <h1 className={cn ('text-2xl font-bold mb-2', className)} {...rest}>
       {children}
     </h1>)
 

frontend/src/lib/materials.ts

@@ -1,41 +1,31 @@
-import {
-    apiGet,
-    isApiError,
-    apiPost,
-    apiPut,
-} from '@/lib/api'
+import { apiGet, isApiError, apiPost, apiPut } from '@/lib/api'
 
-import type {
-    Material,
-    MaterialIndexResponse,
-    MaterialVersion,
-    FetchMaterialsParams,
-    MaterialFilter,
-    MaterialSyncSuppression,
-    MaterialSidebarTag,
-    MaterialTagTree,
-} from '@/types'
+import type { Material,
+	      MaterialIndexResponse,
+	      MaterialVersion,
+	      FetchMaterialsParams,
+	      MaterialFilter,
+	      MaterialSyncSuppression,
+	      MaterialSidebarTag,
+	      MaterialTagTree } from '@/types'
 
 export type FetchMaterialTreeParams = {
     parentId?:       number | null
-    materialFilter:  MaterialFilter
-}
+    materialFilter:  MaterialFilter }
 
-export type MaterialSyncSuppressionResponse = {
-    suppressions: MaterialSyncSuppression[]
-}
+export type MaterialSyncSuppressionResponse = { suppressions: MaterialSyncSuppression[] }
 
 export type MaterialChangesResponse = {
     versions: MaterialVersion[]
-    count:    number
-}
+    count:    number }
 
 const MATERIAL_FILTERS: MaterialFilter[] = ['present', 'missing', 'any']
 
 
 export const parseMaterialFilter = (
     value: unknown,
-    fallback: MaterialFilter = 'present'): MaterialFilter =>
+    fallback: MaterialFilter = 'present',
+): MaterialFilter =>
     typeof value === 'string' && MATERIAL_FILTERS.includes (value as MaterialFilter)
     ? value as MaterialFilter
     : fallback
@@ -45,7 +35,8 @@ export const fetchMaterials = async (
     { q, tagState, mediaKind, createdFrom, createdTo,
       updatedFrom, updatedTo, sort, direction, page,
       tagId, includeDescendants, groupBy,
-      limit }: FetchMaterialsParams): Promise<MaterialIndexResponse> =>
+      limit }: FetchMaterialsParams,
+): Promise<MaterialIndexResponse> =>
     await apiGet ('/materials', { params: {
 	...(q && { q }),
 	tag_state:   tagState,

frontend/src/pages/materials/MaterialDetailPage.tsx

@@ -8,7 +8,6 @@ import WikiBody from '@/components/WikiBody'
 import FieldError from '@/components/common/FieldError'
 import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
-import PrefetchLink from '@/components/PrefetchLink'
 import TabGroup, { Tab } from '@/components/common/TabGroup'
 import TagInput from '@/components/common/TagInput'
 import MainArea from '@/components/layout/MainArea'
@@ -119,12 +118,6 @@ const MaterialDetailPage: FC = () => {
 		 : materialTitle}
 	      </PageTitle>
 
-	      <PrefetchLink
-		  to={`/materials/changes?material_id=${ material.id }`}
-		  className="text-sm text-sky-700 underline underline-offset-2 dark:text-sky-300">
-		この素材の履歴
-	      </PrefetchLink>
-
 	      {(material.file && material.contentType) && (
 		  (/image\/.*/.test (material.contentType) && (
 		      <img src={material.file} alt={material.tag?.name || undefined}/>))
@@ -134,17 +127,12 @@ const MaterialDetailPage: FC = () => {
 		      <audio src={material.file} controls/>)))}
 
 	      <TabGroup>
-		<Tab name="Wiki">
-		  {material.tag
-		   ? (
+		{material.tag && (
+		    <Tab name="Wiki">
 		      <WikiBody
 			  title={material.tag.name}
-			  body={material.wikiPageBody ?? undefined}/>)
-		   : (
-		      <p className="text-stone-700 dark:text-stone-300">
-			タグ未設定の素材です．
-		      </p>)}
-		</Tab>
+			  body={material.wikiPageBody ?? undefined}/>
+		    </Tab>)}
 
 		<Tab name="編輯">
 		  <div className="max-w-wl space-y-4 pt-2">

frontend/src/pages/materials/MaterialHistoryPage.tsx

@@ -80,14 +80,7 @@ const MaterialHistoryPage: FC = () => {
 	</Helmet>
 
 	<div className="space-y-5">
-	  <div className="flex flex-wrap items-center justify-between gap-3">
-	    <PageTitle>素材履歴</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>
+	  <PageTitle>素材履歴</PageTitle>
 
 	  <form
 	      onSubmit={handleSearch}
@@ -112,20 +105,6 @@ const MaterialHistoryPage: FC = () => {
 			onChange={e => setTagInput (e.target.value)}
 			className={inputClass (invalid)}/>)}
 	      </FormField>
-
-	      <FormField label="イベント">
-		{({ invalid }) => (
-		    <select
-			value={eventTypeInput}
-			onChange={e => setEventTypeInput (e.target.value)}
-			className={inputClass (invalid)}>
-		      <option value="">すべて</option>
-		      <option value="create">create</option>
-		      <option value="update">update</option>
-		      <option value="discard">discard</option>
-		      <option value="restore">restore</option>
-		    </select>)}
-	      </FormField>
 	    </div>
 
 	    <button
@@ -150,7 +129,6 @@ const MaterialHistoryPage: FC = () => {
 		  <table className="w-full min-w-[1200px] table-fixed border-collapse">
 		    <colgroup>
 		      <col className="w-48"/>
-		      <col className="w-32"/>
 		      <col className="w-28"/>
 		      <col className="w-24"/>
 		      <col className="w-64"/>
@@ -163,7 +141,6 @@ const MaterialHistoryPage: FC = () => {
 		    <thead className="border-b-2 border-black dark:border-white">
 		      <tr>
 			<th className="p-2 text-left">日時</th>
-			<th className="p-2 text-left">event_type</th>
 			<th className="p-2 text-left">素材 ID</th>
 			<th className="p-2 text-left">版</th>
 			<th className="p-2 text-left">タグ名</th>
@@ -180,7 +157,6 @@ const MaterialHistoryPage: FC = () => {
 			      key={version.id}
 			      className="even:bg-gray-100 dark:even:bg-gray-700">
 			    <td className="p-2">{dateString (version.createdAt)}</td>
-			    <td className="p-2">{version.eventType}</td>
 			    <td className="p-2">
 			      <PrefetchLink to={`/materials/${ version.materialId }`}>
 				#{version.materialId}

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

@@ -33,15 +33,7 @@ describe ('MaterialListPage', () => {
           } },
       )
     })
-    expect (await screen.findByText ('素材はありません．')).toBeInTheDocument ()
-    expect (screen.getByRole ('link', { name: '新規素材を追加' })).toHaveAttribute (
-        'href',
-        '/materials/new',
-    )
-    expect (screen.getByRole ('link', { name: '履歴' })).toHaveAttribute (
-        'href',
-        '/materials/changes',
-    )
+    expect (await screen.findByText ('素材はありません。')).toBeInTheDocument ()
   })
 
   it ('shows materials in the default card view', async () => {
@@ -126,4 +118,63 @@ describe ('MaterialListPage', () => {
     expect (screen.getByText ('サイズ:')).toBeInTheDocument ()
     expect (screen.getByText ('2.0 KB')).toBeInTheDocument ()
   })
+
+  it ('shows the selected tag scope and tag-specific add links', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      materials: [
+        buildMaterial ({
+          id:  10,
+          tag: buildTag ({ id: 30, name: '泣き', category: 'material' }),
+        }),
+      ],
+      count:    1,
+      tagScope: {
+        tag:                { id: 20, name: '伊地知ニジカ', category: 'material' },
+        includeDescendants: true,
+      },
+      groups: [
+        {
+          key:         'tag:30',
+          tag:         { id: 30, name: '泣き', category: 'material' },
+          materialIds: [10],
+          count:       1,
+        },
+      ],
+    })
+
+    renderWithProviders (
+        <MaterialListPage/>,
+        { route: '/materials?tag_id=20&include_descendants=1&group_by=parent_tag' },
+    )
+
+    expect (await screen.findByText (
+        (_, element) => element?.textContent === '伊地知ニジカ 配下の素材を表示中',
+    )).toBeInTheDocument ()
+
+    expect (screen.getByRole ('link', { name: '泣き' })).toHaveAttribute (
+        'href',
+        '/materials?tag_id=30&include_descendants=1&group_by=parent_tag&material_filter=present',
+    )
+    expect (screen.getByRole ('link', { name: 'タグ選択を解除' })).toHaveAttribute (
+        'href',
+        '/materials?material_filter=present',
+    )
+  })
+
+  it ('shows a clear link when tag_id does not resolve to tag_scope', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      materials: [],
+      count:     0,
+      tagScope:  null,
+      groups:    [],
+    })
+
+    renderWithProviders (<MaterialListPage/>, { route: '/materials?tag_id=999' })
+
+    expect (await screen.findByText ('選択中タグが見つかりません．')).toBeInTheDocument ()
+    expect (screen.getByRole ('link', { name: 'タグ選択を解除' })).toHaveAttribute (
+        'href',
+        '/materials?material_filter=present',
+    )
+  })
 })

frontend/src/pages/materials/MaterialListPage.tsx

@@ -10,24 +10,23 @@ import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
 import Pagination from '@/components/common/Pagination'
 import MainArea from '@/components/layout/MainArea'
-import { API_BASE_URL, SITE_TITLE } from '@/config'
+import { SITE_TITLE } from '@/config'
 import { fetchMaterials, parseMaterialFilter } from '@/lib/materials'
 import { materialsKeys } from '@/lib/queryKeys'
 import { dateString, inputClass } from '@/lib/utils'
 
 import type { FC, FormEvent } from 'react'
 
-import type {
-    FetchMaterialsParams,
-    Material,
-    MaterialFilter,
-    MaterialIndexGroup,
-    MaterialIndexGroupBy,
-    MaterialIndexDirection,
-    MaterialIndexMediaKind,
-    MaterialIndexSort,
-    MaterialIndexTagState,
-    MaterialIndexView } from '@/types'
+import type { FetchMaterialsParams,
+	      Material,
+	      MaterialFilter,
+	      MaterialIndexGroup,
+	      MaterialIndexGroupBy,
+	      MaterialIndexDirection,
+	      MaterialIndexMediaKind,
+	      MaterialIndexSort,
+	      MaterialIndexTagState,
+	      MaterialIndexView } from '@/types'
 
 const MEDIA_KIND_LABELS: Record<Material['mediaKind'], string> = {
     image:      '画像',
@@ -42,20 +41,16 @@ const MEDIA_FILTER_LABELS: Record<MaterialIndexMediaKind, string> = {
     video:      '動画',
     audio:      '音声',
     file_other: 'その他ファイル',
-    url_only:   'URL のみ'}
+    url_only:   '外部リンクのみ'}
 
 const SORT_LABELS: Record<MaterialIndexSort, string> = {
     created_at:     '作成日時',
     updated_at:     '更新日時',
     tag_name:       'タグ名',
     media_kind:     '種類',
-    file_byte_size: 'ファイルサイズ',
-    version_no:     'バージョン',
-    id:             'ID'}
-
-const GROUP_BY_LABELS: Record<MaterialIndexGroupBy, string> = {
-    none:       'オフ',
-    parent_tag: '親タグ'}
+    file_byte_size: '容量',
+    version_no:     '版',
+    id:             'Id.'}
 
 
 const setIf = (qs: URLSearchParams, key: string, value: string | null) => {
@@ -88,25 +83,28 @@ const materialTitle = (material: Material): string =>
 
 const groupedTagPath = (
     tagId: number,
-    materialFilter: MaterialFilter): string =>
+    materialFilter: MaterialFilter,
+): string =>
     `/materials?tag_id=${ tagId }&include_descendants=1&group_by=parent_tag`
     + `&material_filter=${ materialFilter }`
 
 
 const materialNewPath = (
     tagName: string,
-    returnTo: string): string =>
+    returnTo: string,
+): string =>
     `/materials/new?tag=${ encodeURIComponent (tagName) }`
     + `&return_to=${ encodeURIComponent (returnTo) }`
 
 
 const clearedTagSelectionPath = (
     locationSearch: string,
-    materialFilter: MaterialFilter): string => {
+    materialFilter: MaterialFilter,
+): string => {
     const qs = new URLSearchParams (locationSearch)
     qs.delete ('tag_id')
     qs.delete ('include_descendants')
-    qs.set ('group_by', 'none')
+    qs.delete ('group_by')
     qs.delete ('page')
     qs.set ('material_filter', materialFilter)
     return `/materials?${ qs.toString () }`
@@ -120,7 +118,7 @@ const MaterialThumb: FC<{ material: Material }> = ({ material }) => (
 		    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"/>
+       ? <img src={material.thumbnail} alt="" className="block h-full w-full object-cover"/>
        : (
 	  <span
 	      className="px-2 text-2xl leading-tight"
@@ -191,27 +189,22 @@ const MaterialListItem: FC<{ material: Material }> = ({ material }) => (
 const GroupHeading: FC<{
     count:          number
     materialFilter: MaterialFilter
-    returnTo:       string
     title:          string
     tagId:          number
-}> = ({ count, materialFilter, returnTo, title, tagId }) => (
-    <div className="flex flex-wrap items-center gap-2 border-b border-stone-200 pb-2
+}> = ({ count, materialFilter, title, tagId }) => (
+    <div className="flex items-center gap-2 border-b border-stone-200 pb-2
 		    dark:border-stone-700">
       <PrefetchLink
 	  to={groupedTagPath (tagId, materialFilter)}
 	  className="font-medium text-sky-700 underline underline-offset-2
-		     dark:text-sky-300">
+		     dark:text-sky-300 w-full">
 	{title}
       </PrefetchLink>
-      <span className="text-sm text-stone-600 dark:text-stone-300">
-	{count} 件
-      </span>
-      <PrefetchLink
-	  to={materialNewPath (title, returnTo)}
-	  className="text-sm text-sky-700 underline underline-offset-2
-		     dark:text-sky-300">
-	このタグに素材を追加
-      </PrefetchLink>
+      <div className="text-right w-auto">
+	<span className="text-nowrap text-sm text-stone-600 dark:text-stone-300">
+	  {count} 件
+	</span>
+      </div>
     </div>)
 
 
@@ -383,8 +376,7 @@ const MaterialListPage: FC = () => {
 		    tagId={group.tag.id}
 		    title={group.tag.name}
 		    count={group.count}
-		    materialFilter={materialFilter}
-		    returnTo={location.pathname + location.search}/>
+		    materialFilter={materialFilter}/>
 		{renderMaterialCollection (groupMaterials)}
 	      </section>)
 	})}
@@ -410,35 +402,15 @@ const MaterialListPage: FC = () => {
 		  src: url(${ nikumaru }) format('opentype');
 		}`}
 	  </style>
-	  <title>{`素材一覧 | ${ SITE_TITLE }`}</title>
+	  <title>{`素材管理 | ${ SITE_TITLE }`}</title>
 	</Helmet>
 
 	<div className="space-y-5">
 	  <div className="flex flex-wrap items-center justify-between gap-3">
-	    <PageTitle>素材一覧</PageTitle>
+	    <PageTitle className="my-auto">素材管理</PageTitle>
 	    <div className="flex flex-wrap gap-2">
-	      <PrefetchLink
-		  to="/materials/new"
-		  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">
-		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>
-	      <PrefetchLink
-		  to="/materials/changes"
-		  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">
-		履歴
-	      </PrefetchLink>
-	      <a
+	      {/* TODO: 局所出力を可能にする */}
+	      {/* <a
 		  href={`${ API_BASE_URL }/materials/download.zip?profile=legacy_drive`}
 		  target="_blank"
 		  rel="noopener noreferrer"
@@ -446,7 +418,7 @@ const MaterialListPage: FC = () => {
 			     text-stone-900 hover:bg-stone-100 dark:border-stone-700
 			     dark:bg-stone-900 dark:text-stone-100 dark:hover:bg-stone-800">
 		ZIP をダウンロード
-	      </a>
+	      </a> */}
 	    </div>
 	  </div>
 
@@ -458,12 +430,6 @@ const MaterialListPage: FC = () => {
 		  {tagScope.tag.name}
 		  {tagScope.includeDescendants ? ' 配下の素材を表示中' : ' の素材を表示中'}
 		</span>
-		<PrefetchLink
-		    to={materialNewPath (tagScope.tag.name, location.pathname + location.search)}
-		    className="font-medium underline underline-offset-2
-			       text-sky-700 dark:text-sky-300">
-		  このタグに素材を追加
-		</PrefetchLink>
 		<PrefetchLink
 		    to={clearedTagSelectionPath (location.search, materialFilter)}
 		    className="font-medium underline underline-offset-2
@@ -471,6 +437,18 @@ const MaterialListPage: FC = () => {
 		  タグ選択を解除
 		</PrefetchLink>
 	      </div>)}
+	  {(tagId != null && tagScope == null) && (
+	      <div className="flex flex-wrap items-center gap-3 rounded-lg border
+			      border-amber-200 bg-amber-50 px-4 py-3 text-sm text-amber-900
+			      dark:border-amber-800 dark:bg-amber-950 dark:text-amber-100">
+		<span>選択中タグが見つかりません．</span>
+		<PrefetchLink
+		    to={clearedTagSelectionPath (location.search, materialFilter)}
+		    className="font-medium underline underline-offset-2
+			       text-amber-800 dark:text-amber-200">
+		  タグ選択を解除
+		</PrefetchLink>
+	      </div>)}
 
 	  {tagState === 'untagged' && (
 	      <PrefetchLink
@@ -522,21 +500,6 @@ const MaterialListPage: FC = () => {
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="グルーピング">
-		{({ invalid }) => (
-		    <select
-			value={groupByInput}
-			onChange={e => setGroupByInput (
-			    e.target.value as MaterialIndexGroupBy)}
-			disabled={tagId == null}
-			className={inputClass (invalid)}>
-		      <option value="none">{GROUP_BY_LABELS.none}</option>
-		      <option value="parent_tag" disabled={tagId == null}>
-			{GROUP_BY_LABELS.parent_tag}
-		      </option>
-		    </select>)}
-	      </FormField>
-
 	      <FormField label="作成日時">
 		{() => (
 		    <div className="flex flex-wrap items-center gap-2">
@@ -579,7 +542,7 @@ const MaterialListPage: FC = () => {
 		      : [
 			  'border-stone-300 bg-white text-stone-900 dark:border-stone-700',
 			  'dark:bg-stone-900 dark:text-stone-100'].join (' ') }`}>
-		カード
+		アイコン
 	      </button>
 	      <button
 		  type="button"
@@ -592,7 +555,7 @@ const MaterialListPage: FC = () => {
 		      : [
 			  'border-stone-300 bg-white text-stone-900 dark:border-stone-700',
 			  'dark:bg-stone-900 dark:text-stone-100'].join (' ') }`}>
-		一覧
+		詳細
 	      </button>
 	    </div>
 
@@ -620,7 +583,18 @@ const MaterialListPage: FC = () => {
 	  {isError && (
 	      <p className="text-red-600 dark:text-red-300">素材一覧の取得に失敗しました．</p>)}
 	  {(!isLoading && !isError && materials.length === 0) && (
-	      <p>素材はありません．</p>)}
+	      <p>
+		素材はありません。
+		{(tagScope && ['character', 'material'].includes (tagScope.tag.category)) && (
+		    <>
+		      <PrefetchLink
+			  to={materialNewPath (tagScope.tag.name, location.pathname + location.search)}
+			  className="font-medium underline underline-offset-2
+				     text-sky-700 dark:text-sky-300">
+			追加してください
+		      </PrefetchLink>。
+		    </>)}
+	      </p>)}
 	  {materials.length > 0 && (
 	      groupBy === 'parent_tag' && groups.length > 0
 	      ? renderGroupedMaterials (groups)

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

@@ -1,5 +1,6 @@
 import { fireEvent, screen, waitFor } from '@testing-library/react'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { Route, Routes, useLocation } from 'react-router-dom'
 
 import MaterialNewPage from '@/pages/materials/MaterialNewPage'
 import { renderWithProviders } from '@/test/render'
@@ -17,6 +18,11 @@ const toastApi = vi.hoisted (() => ({
 vi.mock ('@/lib/api', () => api)
 vi.mock ('@/components/ui/use-toast', () => toastApi)
 
+const LocationView = () => {
+  const location = useLocation ()
+  return <div>{location.pathname + location.search}</div>
+}
+
 describe ('MaterialNewPage', () => {
   beforeEach (() => {
     vi.clearAllMocks ()
@@ -69,4 +75,50 @@ describe ('MaterialNewPage', () => {
     expect (await screen.findAllByText ('ファイルまたは URL は必須です．')).toHaveLength (2)
     expect (screen.getAllByRole ('textbox')[1]).toHaveAttribute ('aria-invalid', 'true')
   })
+
+  it ('returns only to safe material URLs after successful creation', async () => {
+    api.apiPost.mockResolvedValueOnce ({})
+
+    renderWithProviders (
+        <Routes>
+          <Route path="/materials/new" element={<MaterialNewPage/>}/>
+          <Route path="/materials" element={<LocationView/>}/>
+        </Routes>,
+        {
+          route:
+              '/materials/new?tag=%E8%99%B9%E5%A4%8F'
+              + '&return_to=%2Fmaterials%3Ftag_id%3D20',
+        },
+    )
+
+    fireEvent.change (screen.getAllByRole ('textbox')[1], {
+      target: { value: 'https://example.com/ref' },
+    })
+    fireEvent.click (screen.getByRole ('button', { name: '追加' }))
+
+    expect (await screen.findByText ('/materials?tag_id=20')).toBeInTheDocument ()
+  })
+
+  it ('ignores unsafe return_to values after successful creation', async () => {
+    api.apiPost.mockResolvedValueOnce ({})
+
+    renderWithProviders (
+        <Routes>
+          <Route path="/materials/new" element={<MaterialNewPage/>}/>
+          <Route path="/materials" element={<LocationView/>}/>
+        </Routes>,
+        {
+          route:
+              '/materials/new?tag=%E8%99%B9%E5%A4%8F'
+              + '&return_to=https%3A%2F%2Fexample.com%2Fevil',
+        },
+    )
+
+    fireEvent.change (screen.getAllByRole ('textbox')[1], {
+      target: { value: 'https://example.com/ref' },
+    })
+    fireEvent.click (screen.getByRole ('button', { name: '追加' }))
+
+    expect (await screen.findByText ('/materials')).toBeInTheDocument ()
+  })
 })

frontend/src/pages/materials/MaterialNewPage.tsx

@@ -28,6 +28,7 @@ const MaterialNewPage: FC = () => {
   const query = new URLSearchParams (location.search)
   const tagQuery = query.get ('tag') ?? ''
   const returnToQuery = query.get ('return_to') ?? ''
+  const safeReturnTo = returnToQuery.startsWith ('/materials') ? returnToQuery : ''
 
   const navigate = useNavigate ()
 
@@ -55,7 +56,7 @@ const MaterialNewPage: FC = () => {
       onSuccess: async () => {
 	await qc.invalidateQueries ({ queryKey: materialsKeys.root })
 	toast ({ title: '送信成功!' })
-	navigate (returnToQuery || `/materials?tag=${ encodeURIComponent (tag) }`)
+	navigate (safeReturnTo || '/materials')
       },
       onError: error => {
 	applyValidationError (error)

frontend/src/pages/materials/MaterialSearchPage.tsx

@@ -1,51 +0,0 @@
-import { useState } from 'react'
-import { Helmet } from 'react-helmet-async'
-
-import FormField from '@/components/common/FormField'
-import PageTitle from '@/components/common/PageTitle'
-import TagInput from '@/components/common/TagInput'
-import MainArea from '@/components/layout/MainArea'
-import { SITE_TITLE } from '@/config'
-
-import type { FC, FormEvent } from 'react'
-
-
-const MaterialSearchPage: FC = () => {
-  const [tagName, setTagName] = useState ('')
-  const [parentTagName, setParentTagName] = useState ('')
-
-  const handleSearch = (e: FormEvent) => {
-    e.preventDefault ()
-  }
-
-  return (
-      <MainArea>
-	<Helmet>
-	  <title>素材集 | {SITE_TITLE}</title>
-	</Helmet>
-
-	<div className="max-w-xl">
-	  <PageTitle>素材集</PageTitle>
-
-	  <form onSubmit={handleSearch} className="space-y-2">
-	    {/* タグ */}
-	    <FormField label="タグ">
-	      {() => (
-		  <TagInput
-		      value={tagName}
-		      setValue={setTagName}/>)}
-	    </FormField>
-
-	    {/* 親タグ */}
-	    <FormField label="親タグ">
-	      {() => (
-		  <TagInput
-		      value={parentTagName}
-		      setValue={setParentTagName}/>)}
-	    </FormField>
-	  </form>
-	</div>
-      </MainArea>)
-}
-
-export default MaterialSearchPage

frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx

@@ -2,17 +2,13 @@ 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 { createMaterialSyncSuppression, fetchMaterialSyncSuppressions } from '@/lib/materials'
 import { materialsKeys } from '@/lib/queryKeys'
 import { dateString, inputClass } from '@/lib/utils'
 
@@ -22,11 +18,11 @@ import type { MaterialSyncSuppressionSourceKind } from '@/types'
 
 const SOURCE_KIND_LABELS: Record<MaterialSyncSuppressionSourceKind, string> = {
     uri:               'URI',
-    google_drive_path: 'Google Drive path',
-    google_drive_path_prefix: 'Google Drive path prefix',
-    google_drive_file: 'Google Drive file ID',
-    legacy_drive_path: 'Legacy Drive path',
-    legacy_drive_path_prefix: 'Legacy Drive path prefix'}
+    google_drive_path: 'Google Drive ファイル',
+    google_drive_path_prefix: 'Google Drive フォルダ',
+    google_drive_file: 'Google Drive ファイル Id.',
+    legacy_drive_path: '汎用ファイル',
+    legacy_drive_path_prefix: '汎用フォルダ' }
 
 const REASONS = [
     'copyright_high_risk',
@@ -36,7 +32,23 @@ const REASONS = [
     'malware_or_dangerous_file',
     'duplicate_or_low_quality',
     'source_owner_request',
-    'other']
+    'other'] as const
+
+type MaterialSyncSuppressionReason = typeof REASONS[number]
+
+const REASON_NAMES: Record<MaterialSyncSuppressionReason, string> = {
+    ['copyright_high_risk']: '著作権への懸念',
+    ['copyright_takedown']: '著作者からの申出',
+    ['adult_or_sensitive']: '成人向け',
+    ['personal_information']: '個人情報',
+    ['malware_or_dangerous_file']: '危険なソフトウェア',
+    ['duplicate_or_low_quality']: '重複',
+    ['source_owner_request']: '同期元管理者からの申出',
+    ['other']: 'その他' } as const
+
+
+const reasonName = (reason: string): string =>
+    REASON_NAMES[reason as MaterialSyncSuppressionReason] ?? reason
 
 
 const MaterialSyncSuppressionsPage: FC = () => {
@@ -46,7 +58,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
   const [sourceUri, setSourceUri] = useState ('')
   const [drivePath, setDrivePath] = useState ('')
   const [driveFileId, setDriveFileId] = useState ('')
-  const [reason, setReason] = useState (REASONS[0])
+  const [reason, setReason] = useState<MaterialSyncSuppressionReason> (REASONS[0])
 
   const { data, isError, isLoading } = useQuery ({
       queryKey: materialsKeys.suppressions (),
@@ -82,18 +94,11 @@ const MaterialSyncSuppressionsPage: FC = () => {
   return (
       <MainArea>
 	<Helmet>
-	  <title>{`同期元抑止 | ${ SITE_TITLE }`}</title>
+	  <title>{`素材同期抑止 | ${ 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>
+	  <PageTitle>同期抑止</PageTitle>
 
 	  <form
 	      onSubmit={handleSubmit}
@@ -115,7 +120,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="Source URI">
+	      <FormField label="同期元 URI">
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -124,7 +129,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="Drive path">
+	      <FormField label="Google Drive パス">
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -133,7 +138,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="Drive file ID">
+	      <FormField label="Google Drive ファイル Id.">
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -142,15 +147,15 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="理由">
+	      <FormField label="事由">
 		{({ invalid }) => (
 		    <select
 			value={reason}
-			onChange={e => setReason (e.target.value)}
+			onChange={e => setReason (e.target.value as MaterialSyncSuppressionReason)}
 			className={inputClass (invalid)}>
 		      {REASONS.map (value => (
 			  <option key={value} value={value}>
-			    {value}
+			    {REASON_NAMES[value]}
 			  </option>))}
 		    </select>)}
 	      </FormField>
@@ -185,7 +190,8 @@ const MaterialSyncSuppressionsPage: FC = () => {
 		    {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)}
+		    事由: {reasonName (suppression.reason)} /
+		    登録: {dateString (suppression.createdAt)}
 		  </div>
 		</article>))}
 	  </div>