fix(web-client): keep Buffer args for Node deserialize

[kutluhaneth46]

Summary

• The Node napi compat wrapper no longer converts Buffer / Uint8Array arguments into plain arrays.
• Binary inputs stay as Buffer, which napi Buffer / JsBytes APIs (AuthSecretKey.deserialize, Word.deserialize, etc.) require.
• Vec<u8> parameters still accept Buffer, so constructors like rpoFalconWithRNG keep working.

Fixes #364

Test plan

• pnpm --filter @miden-sdk/miden-sdk run test:unit -- js/__tests__/napi-compat.test.js
• On Node with a built native module: round-trip AuthSecretKey.serialize() → Buffer.from(..., "base64") → AuthSecretKey.deserialize(...) via the public package export (not getNativeModule())
• Same for Word.deserialize
• Confirm Uint8Array seeds still work for AuthSecretKey.rpoFalconWithRNG