fix(polymarket): a withdrawal that may have moved money is never signed twice

[VickyXAI]

Summary

• A retry that resolves the earlier withdrawal ends the call. Settled, failed or expired: the outcome is reported and nothing new is signed. Before this, the guard cleared itself and the same confirm:true call signed a second transfer.
• EOA (sigType 0) withdrawals have no deadline. The transfer is signed locally, and its hash, nonce and signed bytes are persisted before the broadcast. Only a receipt resolves it. Until then, a retry re-broadcasts the same bytes, so it can execute at most once.
  • The old 300s expiry is gone. So is any reading of an advanced nonce plus an unknown hash as "dropped".
  • The guard is released before a receipt only on an outright node rejection that the RPC doesn't know. "nonce too low" and "already known" keep it.
• The relayer withdrawal is recorded before submit, not only in the catch, so a process killed mid-POST still leaves the guard. A definite 4xx still releases it.
• HTTP 408 is now an unknown outcome in isDefiniteRejection, which is shared by the CLOB submit, the relayer batch and fund.
• Bumps to 0.54.2 with a CHANGELOG entry.

Test plan

• npm test: 1394/1394
• npm run build
• New tests: test/polymarket-withdraw-eoa.test.ts and test/polymarket-definite-rejection.test.ts. The withdraw and relayer tests were updated for the new lifecycle.
• Mutation-checked: I reverted each of six fixes and confirmed its tests fail.
  1. Resolution continues into a new withdrawal.
  2. EOA time expiry.
  3. "nonce too low" releases the guard.
  4. Fresh signature on retry.
  5. Relayer guard armed only after the submit.
  6. 408 treated as definite.