ALTER TABLE content_items ADD COLUMN item_kind ENUM('posting','ads_campaign','video','website') NOT NULL DEFAULT 'posting' AFTER title;
ALTER TABLE content_items ADD COLUMN campaign_budget DECIMAL(12,2) NULL AFTER published_at;
ALTER TABLE tracking_links ADD COLUMN content_item_id BIGINT UNSIGNED NULL AFTER project_id;
ALTER TABLE tracking_links ADD CONSTRAINT fk_tracking_content FOREIGN KEY (content_item_id) REFERENCES content_items(id) ON DELETE SET NULL;
