BEGIN;
SELECT stock INTO current_stock
FROM inventory
WHERE item_id = $1 FOR UPDATE;

UPDATE inventory
SET stock = current_stock - $2
WHERE item_id = $1;
COMMIT;

const completion = await openai.chat.completions.create({
  model: "gpt-4o",
  temperature: 0.1,
  messages: [
    { role: "system", content: "Extract structured data." },
    { role: "user", content: docText }
  ]
});

const { data, error } = await supabase
  .from('workflows')
  .select('*, steps(*)')
  .eq('status', 'active');

if (error) throw error;
return Response.json(data);