Summary

The MetaboardCfg in the settings crate currently only stores a subgraph url for each metaboard. To support indexing MetaV1_2 events directly from the metaboard contract on-chain, the config needs to also know the contract's address.

Problem

Right now the YAML format for metaboards is a simple key-to-URL mapping:

metaboards:
  my-metaboard: https://subgraph.example.com/metaboard

This is sufficient for querying the metaboard subgraph, but it doesn't provide the on-chain contract address needed by the sync pipeline to fetch events via RPC.

Proposed Change

Add a required address field to MetaboardCfg and update the YAML format to a map:

metaboards:
  my-metaboard:
    url: https://subgraph.example.com/metaboard
    address: 0x...

The old string-only format does not need to be supported — this is a breaking change to the config format.

Scope

• Update MetaboardCfg struct to include a required Address field
• Update YAML parsing to expect the new map format
• Update add_record_to_yaml() for the new format
• Update Default, PartialEq impls
• Update existing tests and add tests for the new format