feat(infra): add P2P handlers, WASM host functions, and distributed storage for decentralized challenges

[echobt]

Summary

Implement comprehensive P2P infrastructure and WASM host function namespaces so that future WASM challenges can operate end-to-end on the decentralized P2P network without any centralized server.

Changes

WASM Runtime (crates/wasm-runtime-interface/)

• New consensus.rs: platform_consensus host function namespace with ConsensusPolicy, ConsensusState, and ConsensusHostFunctions — exposes consensus_get_epoch, consensus_get_validators, consensus_propose_weight, consensus_get_votes, consensus_get_state_hash, consensus_get_submission_count, consensus_get_block_height
• New terminal.rs: platform_terminal host function namespace with TerminalPolicy, TerminalState, and TerminalHostFunctions — exposes terminal_exec, terminal_read_file, terminal_write_file, terminal_list_dir, terminal_get_time, terminal_random_seed with path/command allow-listing
• sandbox.rs: Implement HostFunctionRegistrar for SandboxHostFunctions with real Wasmtime linker registration for sandbox_exec, get_timestamp, log_message
• runtime.rs: Register all new host function namespaces (consensus, terminal, sandbox, exec, time) in WasmRuntime::instantiate() alongside existing network and storage host functions; extend RuntimeState and InstanceConfig with ConsensusState/ConsensusPolicy and TerminalState/TerminalPolicy

P2P Consensus (crates/p2p-consensus/)

• messages.rs: Add 11 new P2PMessage variants (appended at end for bincode backward compatibility): JobClaim, JobAssignment, DataRequest, DataResponse, TaskProgress, TaskResult, LeaderboardRequest, LeaderboardResponse, ChallengeUpdate, StorageProposal, StorageVote — with full message structs
• state.rs: Extend ChainState with leaderboard, active_jobs, task_progress, challenge_storage_roots fields (all #[serde(default)]); add LeaderboardEntry, JobRecord, JobStatus, TaskProgressRecord types; add state methods: assign_job, complete_job, update_leaderboard, get_leaderboard, update_task_progress, update_challenge_storage_root, cleanup_stale_jobs

Validator Node (bins/validator-node/)

• main.rs: Handle all new P2P message types in handle_network_event() with proper logging and state updates; handle previously unmatched messages (StateRequest, StateResponse, WeightVote, PeerAnnounce); add stale job cleanup periodic task (120s interval)
• New challenge_storage.rs: ChallengeStorageBackend implementing StorageBackend trait backed by real LocalStorage from distributed-storage — replaces NoopStorageBackend for production use
• wasm_executor.rs: Wire ConsensusPolicy and TerminalPolicy into InstanceConfig

Challenge SDK WASM (crates/challenge-sdk-wasm/)

• host_functions.rs: Add platform_consensus extern block with all consensus host function imports and safe Rust wrappers (host_consensus_get_epoch, host_consensus_get_validators, host_consensus_propose_weight, etc.)

Notes

• No breaking changes to existing EvaluationInput/EvaluationOutput bincode serialization
• New P2PMessage variants added at end of enum for backward compatibility
• ChallengeStorageBackend moved to validator-node binary to avoid cyclic dependency between wasm-runtime-interface and distributed-storage via platform-core
• All existing tests pass, clippy clean, fmt clean

[coderabbitai]

Warning

Rate limit exceeded

@echobt has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 11 minutes and 22 seconds before requesting another review.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/p2p-wasm-host-infra-v2

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}