feat: separate core package, restore web3js support

[ChiefWoods]

web3js and Kit can be optionally imported through split exports, with clear peerDependency requirements (consumers using litesvm-web3js need not install @solana/kit).

With this PR:

• node-litesvm -> node-litesvm-core(JS package litesvm-core)
• node-litesvm is now the Kit wrapper (JS package litesvm)
• new node-litesvm-web3js as web3js wrapper (JS package litesvm-web3js)

[lorisleiva]

Damn that was quick haha. I'll try and review this asap but I might be a little while since it's a big one.

[lorisleiva]

Thanks for putting this together 🙏

Note: AI-drafted, but reviewed and discussed with me thoroughly.

The overall direction is spot on. The mechanical extraction looks clean and consistent (the internal.* → index.* rename and the litesvm-* → litesvm-core-* binding names all line up).

A few things I'd like us to sort before merging, then some follow-up notes.

Things to fix in this PR

1. Duplicate lint workflows. We've now got two workflows linting the same things on PRs:

• node-build.yml → lint job runs yarn workspace litesvm lint, yarn workspace litesvm-web3js lint, cargo fmt --all, and yarn workspace litesvm-core lint (clippy).
• node-lint.yml → lint job runs core clippy, litesvm lint:js, and litesvm-web3js lint.

So core clippy and both JS lints run twice per PR, across two files, with slightly different invocations. On top of that, the step labelled Clippy core in node-build.yml actually runs yarn workspace litesvm-core lint and sits after the JS steps, which reads like a copy-paste slip. I think that's a genuine bug/typo, right? IMO we should pick one workflow to own linting and strip the overlap out of the other.

2. Redundant Cargo exclude. Excluding crates/node-litesvm from the workspace is correct now that the Kit wrapper is pure TS. But crates/node-litesvm-web3js has no Cargo.toml, so this line is a no-op:

exclude = [
    "crates/node-litesvm",
    "crates/node-litesvm-web3js",  # no Cargo.toml, can drop this
    "crates/node-litesvm/tests/clock-example",
]

Minor, but might as well tidy it.

Versioning

For now I'm happy to keep all three packages pinned to the same version and publish them together, then let them diverge over time as needed. A core bump will always force a wrapper bump anyway (patch/minor/major), so lockstep is a fine starting point. We can revisit per-package release logic once they actually need to move independently.

Follow-up (not blocking this PR)

On the dependency model: right now both wrappers take their SDK as a hard dependency (@solana/kit on litesvm, @solana/web3.js on litesvm-web3js). For an intermediary library the idiomatic approach is either to request the whole SDK as a peerDependency (so the end-user's single version wins) or to depend on the smaller granular packages (e.g. @solana/codecs). This is pre-existing behaviour for the Kit wrapper rather than something this PR introduces, so I don't want to block on it, but let's track it as follow-up work since we're now cementing the pattern across two wrappers.

Lmk what you think, and give me a shout once CI is green and I'll do another pass. 🙂

[ChiefWoods]

2. Redundant Cargo exclude. Excluding crates/node-litesvm from the workspace is correct now that the Kit wrapper is pure TS. But crates/node-litesvm-web3js has no Cargo.toml, so this line is a no-op:

crates/node-litesvm-web3js is included in Cargo.toml because crates is a cargo workspace member.