Understand
Signed Quote Settlement
How signed hookData turns a normal v4 swap into controlled vault settlement.
Problem
An AMM can quote liquidity, but it cannot by itself prove that off-pool issuer capacity, solvency, oracle policy, and signer intent are all safe for the same trade.
Model
Signed quote settlement adds a signed envelope to the swap. The envelope is not an off-chain promise to settle anything at any size. It is a bound: trader, pool, amount, price, expiry, signer, and replay identity must all match.
Flow
Invalid supplied signed quote payloads revert. They do not silently downgrade into vault settlement without a quote. That fail-closed rule is the core safety property.