feat: Jito/Solana backend (additive)

[RonTuretzky]

Additive Jito/Solana backend for the chassis, per the cross-track contract in jito-ncn-program docs/INTERFACES.md (§1 signature domain, §2 VerifyCertificate, §5 router backend). Zero deletions or modifications of the EVM path — new crates + additive workspace registration only (members, dependency entries, a [patch.crates-io] section that is inert for the EVM graph). The EVM default-member clippy/tests run unchanged and green.

Seams

• jito/ crate (peer of eigenlayer/)
  • bn254: key/signature wrappers in the NCN program's signature domain — Solana alt_bn128 compressed wire formats, hash-to-curve and pairings via ncn-program-core (git dep on jito-ncn-program main; imported, never reimplemented). The signature domain is the program's, not the EVM chassis scheme's.
  • scheme::JitoBn254Scheme: implements commonware_cryptography::certificate::Scheme (modeled on core/src/bn254/scheme.rs). Certificates carry exactly the §2 wire triple — aggregated G1 signature (32B compressed), aggregated G2 (64B compressed), signer bitmap — and verify_certificate recomputes apk1 from the bitmap and runs G2Point::verify_aggregated_signature::<Sha256Normalized>, i.e. the program's own verification function (locked by an on-chain parity anchor test).
  • config::NcnDeployment: the NCN deployment JSON (NCN_DEPLOYMENT_PATH), analog of the EVM avs_deploy.json — ncn pubkey, program ids, rpc url, commitment (confirmed minimum; processed rejected), threshold/compute-budget knobs, PDA derivations.
  • network::JitoStakingClient: operators via getProgramAccounts memcmp on NCNOperatorAccount (discriminator @0, ncn @8; ip+port sockets), stake/APK facts from the Snapshot PDA, all reads at confirmed. Produces JitoQuorum with index-aligned participant set / G1 keys / on-chain operator indices / stakes from one sorted construction (participant indices are sorted-G2-set positions, NOT ncn_operator_index — the quorum carries the translation table).
  • quorum: startup reconciliation (§5) — the minimum total stake over all (N−f)-sized signer subsets must clear consensus_threshold_bps, else the router/node refuse to start. Exact arithmetic (BigUint cross-multiplication), unit-tested incl. boundary and overflow cases.
  • instruction: manual §2 VerifyCertificate construction (accounts [ncn_config, ncn, snapshot, restaking_config], all read-only; borsh args hand-rolled and cross-checked against real borsh 0.10). The on-chain bitmap is built byte-exact with ncn_program_core::utils::create_signer_bitmap (LSB-first, padding bits set), verified by a differential test.
  • submitter::JitoSubmitter + SolanaCertificateHandler (the Solana-typed peer of the EVM BlsSignatureVerificationHandler): the submitter resolves a certified height into a CertificateSubmission (§2 triple + expected_generation captured at quorum-assembly time) and hands it to the handler. VerifyCertificateHandler sends the tx with a ComputeBudget, reports Resolution{Executed} only at finalized, and on blockhash expiry rebuilds and resends the transaction (the tx expires, the certificate does not). A settlement handler (INTERFACES §4; Track C settlement_core on branch settlement-program) plugs into the same seam.
• examples/counter-solana/ (common/node/router): wiring mirror of examples/counter — verifier-only engine + sequencer + JitoSubmitter on the router, signing participant with TaskBook/NodeReporter/NodeAutomaton on the node, digest formula sha256(domain ‖ ncn ‖ round) shared via the common crate. Needs a live NCN deployment (deployment JSON + funded payer) — nothing is mocked; unit tests use the real ncn-program-core crypto (host-side signing) end to end. The compose e2e leg comes in a later phase.

TODO-FREEZE markers (parallel-track dependencies)

• VERIFY_CERTIFICATE_DISCRIMINATOR: the phase1-dmsg branch is not pushed yet, so the generated-client discriminator is unknowable. The const is &[10] (the CastVote slot §2 says it replaces) with a pinning test to flip to the generated client's value before any live submission. Note: the program uses 1-byte kinobi/borsh enum discriminators, not 8-byte shank-style — the test pins the length too.
• JitoQuorum.generation: main's Snapshot has no generation field yet (Phase 1 adds it); the seam reports 0 (what Phase 1 reports for a never-mutated set) until the git dep is bumped to read snapshot.generation().
• consensus_threshold_bps: comes from the deployment JSON (default 6667) until Phase 1 lands it on the Config PDA.

Dependency notes (important for maintainers)

• The [patch.crates-io] section mirrors jito-ncn-program's solana pin set (trimmed to used entries) so ONE solana stack (jito-solana fork rev 87dcd08) flows through ncn-program-core, the jito-restaking crates, their spl transitive deps and the jito crate. It is unused by (and inert for) every pre-existing crate.
• Upstream deleted the v2.1-upgrade branch of jito-foundation/restaking that ncn-program-core's manifest still references; its head 358fbc3 remains fetchable by SHA and is pinned in the checked-in Cargo.lock (cargo fetches locked git revs by SHA without resolving the branch). A blanket cargo update will therefore fail against the dead branch — update surgically (cargo update -p <pkg> --precise <ver>) until jito-ncn-program re-pins by rev = (recommended upstream fix; its own fresh clones have the same exposure).

Gates

• cargo fmt --all -- --check: clean
• cargo clippy --all-targets -- -D warnings on the new crates: clean
• cargo clippy --all-targets --all-features -- -D warnings (EVM default members, the CI command): clean
• cargo test --lib --all-features (EVM default members): 43/43, untouched
• cargo test on new crates: 49/49 (real crypto: scheme assemble/verify round-trips, on-chain parity anchor via verify_aggregated_signature, bitmap/borsh differentials, quorum reconciliation)
• cargo check --workspace --all-targets: clean

🤖 Generated with Claude Code