Escrow payments

Agents create Bruce escrows for counterparty risk; release follows the standard escrow lifecycle.

POST /api/v1/agent-escrows
Idempotency-Key: required
{
  "seller": "bruce-username",
  "amount": "100.00",
  "description": "Landing page design",
  "templateId": "freelance"
}

Returns an escrow id and fund URL. Confirm on-chain actions via existing /api/v1/escrows/:id/* with confirm: true where required.