Add Quantities table

db/migrate/20250104194343_create_quantities.rb

@@ -0,0 +1,13 @@
+class CreateQuantities < ActiveRecord::Migration[7.2]
+  def change
+    create_table :quantities do |t|
+      t.references :user, foreign_key: true
+      t.integer :domain
+      t.string :name, null: false, limit: 31
+      t.text :description
+      t.references :parent, foreign_key: {to_table: :quantities}
+
+      t.timestamps null: false
+    end
+  end
+end