掲示板実装

db/migrate/20260218084831_create_boards.rb

@@ -0,0 +1,16 @@
+class CreateBoards < ActiveRecord::Migration[8.1]
+  def change
+    create_table :boards do |t|
+      t.integer :game_id, null: false
+      t.string :board_type, null: false, default: 'negotiation'
+      t.integer :created_by_participant_id
+      t.boolean :is_public, null: false, default: false
+
+      t.timestamps
+    end
+
+    add_index :boards, :game_id
+    add_index :boards, :board_type
+    add_foreign_key :boards, :games
+  end
+end