Add RPC URL for Liquichain (chainId 1662)

[smichea]

Adds the public JSON-RPC endpoint for Liquichain (chainId 1662). The chain has been registered here for several years; this PR fills in the previously empty rpc array so wallets and aggregators (chainlist.org, etc.) can auto-configure the network.

Changes

• _data/chains/eip155-1662.json: add https://mainnet.liquichain.io/rpc to the rpc array.

Verification

The endpoint is live and responds to standard EVM JSON-RPC:

$ curl -s -X POST https://mainnet.liquichain.io/rpc \
    -H 'Content-Type: application/json' \
    -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x67e"}

0x67e = 1662, matching the registered chainId.

No other fields are modified.

[github-actions]

You successfully submitted a PR! Due to the amount of PRs coming in: we will only look at PRs that the CI is happy with. We can also not hold your hand getting the CI green - just look how others that where merged did it and RTFM. So as long as there is any CI check that reports an error - no human will look at this. You might be able to ask for some support after supporting the project - e.g. by sending funds to lists.eth. When you fixed things after a requested change - then you also need to (re-)request a review.

[github-actions]

PR merged - please consider contributing some funds to lists.eth