docs: add deposit-wallet address migration runbook

[arunimshukla]

Summary

Adds a documentation-only migration runbook for integrations that used UUPS-only deriveDepositWallet() or persisted an earlier deposit address.

• Documents version 0.0.10 and the current factory/beacon/legacy-wallet address-selection matrix.
• Adds a read-only TypeScript preflight that stops on a stored-address mismatch.
• Separates address selection, relayer deployment checks and recovery of earlier deposits.
• Adds a redacted evidence checklist and links the runbook from the existing README.

Context and boundaries

Related to #39 and Polymarket/py-builder-relayer-client#27. This PR does not resolve their recovery requests, verify reported balances, submit transactions or introduce an operator-recovery procedure.

The behaviour was checked against src/client.ts and src/builder/derive.ts at upstream commit 9122f6fb1856f1ecfe4406685bfa19a2c5a7b290. An existing deployed UUPS wallet remains selected; upgrading the package alone does not change calls to the deprecated standalone helper.

Validation

• 13 offline checks on extracted/transpiled upstream source methods, with mocked RPC and deterministic-address helpers.
• 7 offline checks on the exact documentation snippet: new records, matching addresses, case-insensitive comparison, undeployed result, mismatch and RPC/relayer errors.
• Relative links and README anchors checked; existing addresses and unrelated README text preserved.
• Remote commit verified to be one commit ahead of upstream, changing only these two Markdown files.

The full SDK test suite was not run. These checks validate documented selection/preflight behaviour, not CREATE2 cryptography or live relayer availability.

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Note

Low Risk
Documentation-only changes with no runtime, auth, or deployment behavior changes.

Overview
Adds a deposit-wallet migration runbook for integrators who still call deprecated deriveDepositWallet() or reuse a stored funding address, and links it from the README deposit-wallet section.

The runbook documents upgrading to client.deriveDepositWalletAddress() (v0.0.10+), the factory beacon vs legacy UUPS address-selection matrix, and that derivation alone does not deploy wallets or recover prior deposits. It adds a read-only getDepositWalletPreflight pattern that re-derives the address, fails on a persisted mismatch, and checks relayer deployment via getDeployed(). A final section sets expectations for earlier-deposit recovery (operator path, redacted evidence checklist) and points to related GitHub issues without promising a user SDK workflow.

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