fix(connect-evm): normalize account request returns

[wenfix]

Explanation

This fixes the EIP-1193 return shapes for intercepted Connect EVM account requests while preserving the existing request routing through the Connect EVM interceptor and connect() flow.

Previously, provider.request({ method: 'eth_requestAccounts' }) resolved to the higher-level client.connect() result:

{ accounts, chainId }

EIP-1193 consumers expect the method-specific result instead, so eth_requestAccounts now resolves to the accounts array:

accounts

The same audit found eth_coinbase sharing the eth_accounts handler and returning the full accounts array. eth_coinbase now resolves to the selected account, while eth_accounts continues to resolve to the full accounts array.

wallet_requestPermissions intentionally keeps the existing Connect EVM return shape for this PR.

References

• Related external validation: Migrate to @metamask/connect-evm thirdweb-dev/web3-onboard#2390
• EIP-1193 requires provider.request() to resolve with the requested method's result.
• EIP-1102 specifies eth_requestAccounts resolves to an accounts array.

Testing

• yarn workspace @metamask/connect-evm test:unit
• yarn tsc --noEmit -p packages/connect-evm/tsconfig.json

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes