Перевод проекта на единую SQLite БД, WAL и обновление README для Windows

config/db/migrate/20260303180000_create_cards.rb

@@ -0,0 +1,16 @@
+Sequel.migration do
+  change do
+    create_table :cards do
+      primary_key :id
+
+      column :name, String, null: false
+      column :elixir_cost, Integer, null: false
+      column :rarity, String
+      column :type, String
+      column :is_meta, Integer, default: 0
+
+      column :created_at, DateTime, null: false, default: Sequel::CURRENT_TIMESTAMP
+      column :updated_at, DateTime, null: false, default: Sequel::CURRENT_TIMESTAMP
+    end
+  end
+end

config/db/migrate/20260303200000_enable_sqlite_wal.rb

@@ -0,0 +1,11 @@
+Sequel.migration do
+  up do
+    run "PRAGMA journal_mode = WAL;"
+    run "PRAGMA synchronous = NORMAL;"
+  end
+
+  down do
+    run "PRAGMA journal_mode = DELETE;"
+    run "PRAGMA synchronous = FULL;"
+  end
+end