fix(types): normalize Buffer API boundaries

[siisee11]

Summary

• copy Node Buffer values into ArrayBuffer-backed Uint8Array values before passing them to WebAssembly, Blob, Protobuf, and crypto APIs
• keep audit payload serialization and corruption tests byte-for-byte equivalent without relying on incompatible Buffer overloads
• restore typecheck compatibility when OneQuery is consumed as the Velen workspace submodule

Validation

• mise exec -- bunx turbo typecheck --json --filter=@onequery/db --filter=@onequery/server --filter=@onequery/cli-server
• mise exec -- bunx oxlint <changed-files> --type-aware --type-check --format json
• mise exec -- bun run format
• mise exec -- bunx turbo test --json --filter=@onequery/db --filter=@onequery/server --filter=@onequery/cli-server — 461 tests passed

Context

Velen local CI typechecks affected OneQuery packages from the parent workspace. The previous direct Buffer API calls failed under that combined Node and Bun type environment even though their runtime bytes were valid.