It might be good to have a viem utils package that provides things like an auto-populated defineChain object based on your Paima .env file (todo: do we need anything else?)

Since Viem has its own wallet type and provider type, probably this should go in @paima/providers. I'm not sure if we want this to be separate from the EthersProvider, or if we want a separate "PrivateKey" type that can be turned into an EthersProvider or a Viem provider (but such an option may be difficult to compose with things like the Thirdweb SDK)

In other words, we need 3 things:

1. A wrapper for defineChain that gets the Paima env variables and falls back to the viem built-in definition if one exists for the chain id
2. A wrapper for createPublicClient
3. A wrapper for createWalletClient

Since wagmi uses Viem under the hood, we can use these Viem definitions for a wagmi lib as well (see #292 for more)

const config = createConfig({
  chains: [paimaChain], // use Viem chain definition as-is
  client() {
    return paimaPublicClient; // use Viem public client definition
  },
})