[littlehand26]

Summary

This PR consolidates the complete Arc mainnet implementation and release-validation work into one review unit. It includes the Arc chain configuration, EVM behavior, protocol rules, stateful precompiles, finalized updater validation, RPC query and estimation APIs, producer fixtures, and the A1/A8 validation suites.

Supersedes #213, #214, #215, #216, #217, #218, #219, and #221.

#209 is intentionally excluded. It addresses a generic BlockFile warmup issue and is not part of this Arc feature branch. This PR does not enable BlockFile warmup.

Integration notes

• Based on current main at c9c51f65edddd0654d6a7929498c93319f24d159.
• Preserves the block-hash-keyed StateDiff behavior added by fix(s3): key HyperEVM stateDiff objects by block hash #222 for chain 999.
• Adds Arc finalized-notification and parent-continuity validation without changing the chain 999 storage layout.
• Keeps the canonical-genesis fixture refresh and its Arc writer provenance.
• Does not include either commit from fix: infer warmup create transactions from root traces #209; its two modified paths have no net diff from main.

Validation

• Arc Python validation: 62/62 unit tests passed.
• leafage-evm-chains: 447 passed, 0 failed, 4 ignored.
• leafage-evm-rpc library: 101 passed, 0 failed.
• RPC integration: e2e_smoke 2/2 and arbitrum_retryable_estimate 1/1 passed.
• Locked metadata and targeted package checks passed.
• Fixture manifest: 22/22 payload hashes and sizes verified.
• Kimi and Claude cross-review found no product Blocker or P1 in the frozen Arc implementation.

One generic binary test on main requires a local RPC at 127.0.0.1:3545; without that external fixture, the consolidated run was 53 passed and 1 connection-refused failure. The test file is unchanged from main.

Scope boundaries

• No public RPC or testnet checks.
• No Kafka batching patch.
• No BlockFile warmup change from fix: infer warmup create transactions from root traces #209.
• Existing accepted Arc RPC behavior for web3_clientVersion, readiness, and reasonless REVERT is unchanged.