fix(ci): make protobuf JavaScript codegen portable

[BitHighlander]

Summary

• declare the JavaScript protobuf compiler as a repository-owned build dependency
• pin a compatible google-protobuf runtime for generated boolean accessors
• exercise JavaScript generation in Protocol CI on the staging branch
• keep npm and Yarn lockfiles aligned

Root cause

Vault CI built the exact device-protocol submodule, but device-protocol relied on a globally installed protoc-gen-js. Local macOS builds passed because Homebrew supplied it; clean GitHub runners failed. A clean container then exposed the old runtime mismatch as well.

Validation

• fresh node:20-bookworm container: npm ci
• fresh container: npm run build:js
• Ironwood fields 19/20 serialization round-trip
• Zcash action boolean serialization round-trip
• generated Solana token_recipient_owner accessors present
• protoc descriptor compilation
• tools/check_zcash_contract.py

No protobuf wire definitions change in this PR. No package publish is part of this work.