Enable Arbitrum Native Precompile Support for Local Testing

Local development for Arbitrum precompiles ArbSys and ArbGasInfo fully enabled across Milestones 1–5. Tools include Hardhat, Foundry, Anvil shim. GitHub repo hosts public probes, validation scripts with ERC-20/721 tests, docs at ox-rollup.com, and a demo dapp using ArbSys for block-timed vesting plus ArbGasInfo for L1 gas reimbursement. Support and roadmap updates ongoing.