Add full protocol support for both Optimism subgraphs and SPS

Executive Summary

This GGP proposes adding full protocol support for Optimism subgraphs and Substreams-powered subgraphs (SPS).

Context

As part of the new Chain Integration Process (CIP) GIP (3-stage simplified overview here), the Optimism team has formally requested protocol integration via The Graph’s Forum. Council ratification of indexing rewards on this new Subgraph Data Source is the last step of that process.

Description

Optimism is already supported in the Subgraph Studio (1st stage), and the Optimism stack and docs have been tested for reliability and determinism issues during subgraph syncing. InfraDAO conducted this testing as part of stage 2 of the CIP. As stated in the CIP, full protocol support for a new subgraph data source (chain) requires a final vote in favor of the Council. Hence, this GGP. Furthermore, support for SPS is bundled into this GGP given the newly launched Optimism Firehose (based on EVM JSON-RPC polling), built by the StreamingFast team (related GIP here).

Next Steps

1. Pending Council approval, the canonical Subgraph feature support matrix will be updated and the related PR merged, effectively signaling full protocol support for Optimism subgraphs and SPS on mainnet.
2. InfraDAO's Indexer-focused documentation on how to set up the Optimism node for subgraph and SPS syncing will be added to the protocol's canonical documentation page. This will include the newly launched Firehose Optimism.