feat(wallets): add create wrapper for crypto deposit accounts

[ss-privy]

Summary

Stainless generates _create for Node on this endpoint (AuthContextBackingMethods) because TypeScript cannot overload create with an authorization-context argument. This adds the public create wrapper that signs via authorization_context, the same pattern as wallets().earn().ethereum().deposit().

await privy.wallets().depositAccounts.crypto.create(walletId, {
  deposit_config_id: 'clg2rvssg025ny5fmul5m95fn',
  authorization_context: { authorization_private_keys: [key] },
});

Base is main (not next) so this sits on top of the generated crypto deposit _create from feat(api): api update.

Test plan

• tsc --noEmit passes
• Confirm create shows up on client.wallets().depositAccounts.crypto after install
• Optional: create a crypto deposit account against staging with an owner authorization key

Made with Cursor

[ss-privy]

Closing in favor of #202.

Same wrapper; 202 also applies WithExpiry (so privy-request-expiry is not left on the public input / signed as body) and imports CreateCryptoDepositAccountResponse from the generated barrel. Better public-type freeze before create() has consumers.

Thirteen Grok reviews of this PR were 13–0 SHIP; none of the deltas in 202 were blockers, but they were the repeated should-fix items.