-- Biome column for enemy templates (canonical ids from internal/world levelBands).
-- For databases that ran 000006a before biome existed; fresh installs get column from 000006a_head.
ALTER TABLE public.enemies ADD COLUMN IF NOT EXISTS biome text;

UPDATE public.enemies
SET biome = substring(type from '[^_]+$')
WHERE biome IS NULL OR trim(biome) = '';

ALTER TABLE public.enemies ALTER COLUMN biome SET NOT NULL;