feat: dynamic eventFilters for wildcard handlers (cross-contract address sharing) #1201

Summary

For wildcard handlers (e.g. ERC20.Transfer, ERC721.Transfer), allow eventFilters to be a function whose addresses argument comes from a different contract's dynamically-registered set — so HyperSync can pre-filter at the source instead of every event reaching the handler.

Use case

Indexing every Aragon DAO across Ethereum mainnet plus tracking each DAO's treasury (every ERC-20 / ERC-721 transfer where from or to is a DAO).

DAOs are discovered dynamically via DAORegistered and registered with:

indexer.onEvent({ contract: "DAORegistry", event: "DAORegistered" }, async ({ event, context }) => {
  context.chain.DAO.add(event.params.dao);
});

Treasury currently uses a wildcard ERC20.Transfer handler that filters at handler-time:

indexer.onEvent(
  { contract: "ERC20", event: "Transfer", wildcard: true },
  async ({ event, context }) => {
    const [fromDao, toDao] = await Promise.all([
      context.Dao.get(daoId(event.chainId, event.params.from)),
      context.Dao.get(daoId(event.chainId, event.params.to)),
    ]);
    if (!fromDao && !toDao) return;
    // ...record Transaction + update Asset balance
  },
);

Every Transfer on every ERC-20 in Ethereum history reaches this handler just to drop the vast majority via the Dao.get early-return.

Desired API

eventFilters as a function on a wildcard handler, with addresses populated from the dynamically-registered set of another contract:

indexer.onEvent(
  {
    contract: "ERC20",
    event: "Transfer",
    wildcard: true,
    eventFilters: ({ addresses }) => [
      { from: addresses },   // transfers FROM a DAO
      { to:   addresses },   // OR to a DAO
    ],
    // optional: name the contract whose registered addresses feed `addresses`
    eventFiltersAddressSource: "DAO",
  },
  async ({ event, context }) => { /* same as today, but only DAO-touching transfers reach here */ },
);

ERC20.Transfer.eventFilters already accepts { from?, to? } in the typed surface (.envio/types.d.ts); the missing piece is letting the function form work on wildcard handlers and pointing it at another contract's address registry.

Open questions

1. How should the cross-contract address source be expressed? An explicit field like eventFiltersAddressSource: "DAO", or a different mechanism?
2. Any preview / alpha branch we can test against with a real Ethereum-mainnet workload?

Happy to validate a preview build against our indexer if useful.