ALTER TABLE `topics` ADD `status` text DEFAULT 'pending' NOT NULL;
ALTER TABLE `lessons` ADD `cost_ai` real DEFAULT 0;
ALTER TABLE `lessons` ADD `cost_audio` real DEFAULT 0;
ALTER TABLE `lessons` ADD `cost_branch_ai` real DEFAULT 0;
ALTER TABLE `lessons` ADD `cost_branch_audio` real DEFAULT 0;
ALTER TABLE `lessons` ADD `cost_total` real DEFAULT 0;
ALTER TABLE `lessons` ADD `branch_status` text DEFAULT 'pending' NOT NULL;