chore(deploy): migrate to Hardhat v3 + hardhat-deploy v2 (rocketh)

[FabienCoutant]

Overview

Migrates the deployment toolchain from Hardhat v2 + hardhat-deploy v0.14 (ethers v5) to Hardhat v3 + hardhat-deploy v2 built on rocketh (viem), mirroring the parallel-parallelizer setup. Smart contracts and Foundry tests are unchanged.

Motivation: the old hardhat-deploy is unmaintained for Hardhat v3, and its ethers v5 path is what caused the post-deploy to:"" crash on the recent sPRL2V2 mainnet deploy.

Stack

hardhat@3, hardhat-deploy@2, rocketh + @rocketh/* (0.19.x), viem, @nomicfoundation/hardhat-viem. ESM ("type": "module").

Changes

Foundation

• package.json: "type": "module"; deps swapped; scripts (verify → rocketh-verify etherscan, add size); dropped hardhat-foundry / hardhat-contract-sizer.
• tsconfig.json: ESM (esnext / bundler), @rocketh + @generated/* path aliases.
• hardhat.config.ts: v3 plugins array, networks type: "http", PRIVATE_KEY accounts, solc 0.8.25/cancun. Hardhat sources pinned to contracts/ and its test dir redirected so Foundry tests under test/ are not compiled by Hardhat. remappings.txt gains contracts/=contracts/.
• rocketh.ts (new): typed config + deploy/read-execute/proxy/viem extensions, setupDeployScripts, re-exports generated artifacts.
• commitlint.config.js → .cjs (CommonJS under ESM).

Deploy scripts (sPRL1/sPRL2/sPRL2V2, MainFeeDistributor, SideChainFeeCollector, RewardMerkleDistributor)

• Rewritten to the deployScript(env) API: env.deploy({ account, artifact, args }), network name via env.name, uint args as BigInt.
• deploy/utils switched from ethers v5 to viem (isAddress / zeroAddress).
• Removed the obsolete sPRL2V2.recover.ts and utils/getVerifyConfig.ts.

Verification now uses @rocketh/verifier (ETHERSCAN_API_KEY env, Etherscan V2); .env.example updated.

Validation (CI green locally)

• tsc --noEmit clean.
• forge fmt --check, solhint, prettier:check pass.
• forge build --sizes + hardhat compile generate generated/ artifacts.
• forge test: 188 passed, 0 failed.
• End-to-end deploy dry-run of sPRL1 on an in-memory network succeeds (arg encoding + bytecode broadcast + deploy).

Notes

• Hardhat 3 is still in beta.
• The parallel-parallelizer committed rocketh.ts is stale vs its installed rocketh 0.19 (uses the removed setup API); this PR uses the correct 0.19 setupDeployScripts API.
• Requires ETHERSCAN_API_KEY (unified V2 key) in .env for verification.
• Pre-existing deploy/config WIP changes are intentionally left out of this PR.