fix(node): accept plain slot hash inputs

[xternet]

Summary

Fixes #178.

TypeScript accepts a structural { slot, hash } value for setSlotHashes, but the native method previously required references to the NAPI SlotHash class. At runtime, a plain object therefore failed with Failed to recover SlotHash type from napi value.

Add a setter-only SlotHashInput NAPI object and accept that input in the native setter. The existing SlotHash NAPI class is deliberately preserved for getter results and runtime compatibility.

Compatibility

• SlotHash remains an exported runtime class.
• getSlotHashes() continues to return SlotHash instances.
• Existing SlotHash instances remain structurally valid setter inputs.
• Plain { slot, hash } object literals now work as the public TypeScript signature implies.

Regression test

The new test passes an object literal to setSlotHashes, checks the values returned by getSlotHashes, and asserts that the returned value is still instanceof SlotHash.

Validation

• Full Node test suite — 23 passed
• yarn build:js
• yarn lint:js
• cargo test -p litesvm-node
• cargo clippy -p litesvm-node --all-targets
• cargo +nightly fmt --all -- --check
• git diff --check

[Aursen]

Thank you for the fix