ALTER TABLE sessions ADD COLUMN model_without_qwen TEXT
    CHECK (model_without_qwen IS NULL OR model_without_qwen IN (
        'deepseek-v4-flash-0731',
        'deepseek-v4-pro',
        'glm-5.2',
        'glm-5.3-flash'
    ));
UPDATE sessions SET model_without_qwen = CASE
    WHEN model = 'qwen3.8-flash-next' THEN NULL
    ELSE model
END;
ALTER TABLE sessions DROP COLUMN model;
ALTER TABLE sessions RENAME COLUMN model_without_qwen TO model;
