Lean bindings

Native EIP-8288 Lean backend for Nethermind, packaged for NuGet as Nethermind.Crypto.Lean.

The library, libnethermind_lean.so, is built from the Rust crate in src/ffi, a thin C ABI over a pinned leanVM fork.

• Native-only: no managed assembly. Nethermind's NativeLeanProofVerifier loads the library and, on chains with EIP-8288 scheduled, checks the CPU features, ABI version, aggregated verification key and acceptance bounds at startup.
• Version <native version>.<run>: the native version is the src/ffi crate version.
• glibc 2.35 (Ubuntu 22.04) or newer: Build Lean fails if the library needs a newer glibc symbol.
• No other RIDs: an EIP-8288 node on osx, win or musl fails at startup with Nethermind's backend message; other chains never load the library.

• src/ffi: the Rust source of the library, and the cargo-about configuration (about.toml, about.hbs) for THIRD-PARTY-NOTICES.
• src/bindings/Nethermind.Crypto.Lean: the package; runtimes/*/native/libnethermind_lean.so (Git LFS) are committed by Build Lean.
• src/bindings/Nethermind.Crypto.Lean.Tests: loads the committed library and checks its ABI version and aggregated verification key.

• Build Lean (manual): builds src/ffi for each RID, twice, and fails unless both builds are byte-identical; generates THIRD-PARTY-NOTICES; runs the smoke test on the built libraries on x64 and arm64 hardware; optionally opens a pull request with them into the branch it runs on. That pull request is opened with GITHUB_TOKEN, which starts no workflows, so run Test / Publish on its branch manually.
• Test / Publish: on pull requests and main, checks formatting, runs the Rust tests, the smoke test and Nethermind's native suite (startup checks and real verifications, with fixtures from src/ffi) against the committed library on x64 and arm64 hardware, and verifies a consumer gets the right library per RID. On a release or a manual run, publishes to NuGet (staging or production) through trusted publishing, only after all of these pass.

This project is licensed under the MIT license.

The shipped library statically links leanVM and other Rust crates, used under permissive licenses. See THIRD-PARTY-NOTICES for the full texts.