Deploy the caller's Polymarket deposit wallet and set its trading approvals

Creates the user's deposit wallet — a per-user ERC-1967 proxy on Polygon, deployed through Polymarket's relayer at a deterministic CREATE2 address derived from the owner EOA. A new setup can submit a deployment transaction, then a signed batch setting the CTF/collateral approvals the venue needs; retries can reuse completed state. Idempotent on the deployment leg. Re-submitting for an already-deployed owner is treated as a no-op success and comes back with deploy_tx_id: null. It does not move user funds — it deploys a contract and grants approvals. The approval batch is signed server-side under the user's delegated key; the batch deadline window is one hour, and each relayer transaction is waited on for up to 120 s. A successful response means any approval batch submitted by this call has confirmed. batch_tx_id is its relayer transaction id, already-complete for a saved onboarding checkpoint, reconciled when a pending approval was found complete on-chain, or an empty string when this request submitted no batch. The special values are not relayer transaction ids. Auth & scope. Requires trade:execute for polymarket, identity ownership, and the mutation gate.