Build a Ponder indexer for IMDOracleDisputeRegistry from launch 177 (this commit), live on Sepolia at 0xbcd93c85adb43628b6b0e4257c864158351b4ecb and deployed in block 11781401 (verified 2026-09-27). ABI: docs/abi/IMDOracleDisputeRegistry.json. Events: DisputeOpened(disputeId, challenger, requestId (bytes16, indexed), sourceChainId, attestationSnapshotHash, evidenceHash, evidenceURI, rationale, createdAt), ResponseAdded(disputeId, responseIndex, author, evidenceHash, evidenceURI, text, createdAt), DisputeWithdrawn(disputeId, challenger, withdrawnAt). A dispute is Open until its challenger withdraws it; there is no other transition, and nothing is ever edited or deleted.

Tables: dispute (id, challenger, requestId as 0x-hex and as a UUID string 8-4-4-4-12, sourceChainId, both hashes, evidenceURI, rationale, createdAt, status open|withdrawn, withdrawnAt, responseCount, tx hash, block); response (disputeId, index, author, evidenceHash, evidenceURI, text, createdAt, tx hash); request (requestId, openCount, totalCount). GraphQL must answer: the open disputes for a given requestId, newest first; all responses for a dispute in index order; requests ordered by open dispute count. Every string is untrusted user input: store it verbatim and never render it as HTML in examples.

The live registry had no events on 2026-09-27, so prove the handlers locally too: start anvil, deploy the registry from this repository with forge create, call openDispute twice for one requestId and once for another, respond twice, withdraw one, run Ponder against anvil (chain 31337 as a second chain in ponder.config.ts, chosen by an environment variable), and commit the GraphQL queries and their output to indexer/VERIFY.md. Then sync Sepolia from block 11781401 to the head and record that it completes (empty tables are the expected result until someone uses the registry). Put everything under indexer/ (package.json, ponder.config.ts, ponder.schema.ts, src/, README.md) without touching the Foundry project; read RPC URLs from PONDER_RPC_URL_11155111 and PONDER_RPC_URL_31337 and document a public Sepolia endpoint.