TwinTrade 0.40.0 — Exact allowance verification

Live opens now replace any different USDC allowance with the exact six-decimal collateral amount and read it back after confirmation. If the confirmed allowance differs, TwinTrade records the mismatch and does not simulate or submit the trading transaction.

Replacement approval transaction hashes are persisted so approval-only recovery follows the transaction that actually mined. Regression coverage verifies oversized-allowance reduction, signer binding, exact read-back, replacement-hash journaling, and rejection before submission. The release also corrects stale version documentation. No funded live transaction was sent during validation.