The End-to-End Tests section listed, as the third of three standing limits
of the dApp coverage, the EIP-1193 error code not surviving the last hop
into the page. That stopped being true when `9dcd875` landed
(#274): the provider now rejects
with a `ProviderRpcError` carrying `code`, and the e2e suite asserts the
code on the page as well as on the wire.
The other two limits are still accurate against the current code and are
left alone.
