add screen reader mode

db/migrate/20260416100000_create_document_metadata.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class CreateDocumentMetadata < ActiveRecord::Migration[8.1]
+  def change
+    create_table :document_metadata do |t|
+      t.references :account, null: false, foreign_key: true, index: false
+      t.string :blob_checksum, null: false
+      t.text :text_runs, null: false
+
+      t.datetime :created_at, null: false
+    end
+
+    add_index :document_metadata, %i[account_id blob_checksum], unique: true
+  end
+end