feat: pnpm migration, contracts precompiles build & npm publish

[nowooj]

Closes: #428

Temporary published package: cosmos-evm-contracts
If you want to keep using this package name, I will transfer npm package ownership from the account that published it.

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1. contracts package – precompiles build & npm publish

• Precompiles-only build: Build .sol and ABI into dist/ from solidity/precompiles, excluding testdata and testutil
• Publish config: files, exports, and prepublishOnly so npm publish runs the build and exposes the right entry paths

Path	Change
contracts/scripts/build-precompiles.js	New. Precompiles build script
contracts/package.json	build:precompiles, compile, prepublishOnly, files, exports; packageManager, deps, etc.
contracts/README.md	New. Installation, package structure, usage
contracts/.gitignore	Add dist/
contracts/hardhat.config.js	Config updates
contracts/pnpm-lock.yaml	Lockfile (pnpm)

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2. pnpm migration (reason)

• Faster installs and less disk usage via a content-addressable store
• Strict dependency resolution to avoid phantom dependencies and keep the dependency tree predictable
• Built-in workspace support for the repo’s multiple packages (contracts/, tests/, evm-tools-compatibility, etc.)

CI, scripts, and lockfiles across the repo are updated to use pnpm accordingly.

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How to verify

# Full contract compile
make contracts-all  # or use scripts/compile_smart_contracts

# Build contracts precompiles
cd contracts && pnpm install && pnpm run build:precompiles

How to publish

cd contracts

# 1) Log in to npm (once)
npm login

# 2) Publish (prepublishOnly runs build:precompiles)
pnpm publish

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Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• tackled an existing issue or discussed with a team member
• left instructions on how to review the changes
• targeted the main branch

[nowooj]

Rebase on main