Rebuild engine.wasm under Rust 1.98.1

The toolchain bump changes the compiled output, so the committed module
no longer reproduces and verify-rust.sh fails on it. Rebuilt with
./scripts/build-wasm.sh, which sources wasm-rustflags.sh so the producer
and the checker pass identical flags. Size is unchanged at 322017 bytes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: wormeyman