Add Robinhood foundational metadata

[0xRobin]

Adds Robinhood foundational metadata in one draft PR: base source/docs definitions, evms.info, and aggregate EVM inclusion. Public docs/Chainlist support chain ID 4663, ETH native gas, Layer 2, Arbitrum Orbit, Ethereum blobs, and Ethereum settlement; explorer and wrapped native token address remain unconfirmed. Robinhood prices token metadata is deferred to CUR2-2927.

[cursor]

PR Summary

Low Risk
Static seed/metadata only; no auth or runtime logic, though draft UNKNOWN token rows could mislabel USD pricing until metadata is verified.

Overview
Registers Robinhood Chain (chain id 4663) across the EVM catalog and token pricing pipeline so downstream spells can treat it like other onboarded chains.

evms_blockchains_list gains robinhood, and evms.info adds a static row as Layer 2 with native ETH, is_on_dune true, and null explorer / wrapped-native fields until they are confirmed. prices_tokens unions in a new prices_robinhood_tokens model plus _schema.yml tests.

The Robinhood prices seed is explicitly draft: ~20 contract addresses from top erc20_robinhood transfers, with UNKNOWN symbols and null CoinPaprika ids/decimals pending tokens.erc20 or integration-form validation.

^{Reviewed by Cursor Bugbot for commit b8a7971. Configure here.}