Heirloom is a non-custodial, immutable inheritance vault for ERC-20 tokens on Arc. Its standalone contract contracts/ArcInherit.sol holds one shared contract with per-owner vaults: an owner names percentage-split heirs and sets a check-in timelock plus grace period, and if the owner stops checking in (proof of life), each heir can claim their share once both windows pass. v2 makes payouts order-independent by snapshotting the vault balance on the first claim of a round, adds claim rounds that recover cleanly from false alarms so later deposits are never stranded, and makes claims retryable when USDC blocklists a recipient. The contract exposes a UI-ready read surface — getVault, getBalances, canClaim, timeUntilClaim, claimSnapshot, claimRound, and events — and ships a 48-test Hardhat suite with a BlockableERC20 mock that reproduces USDC-blocklist reverts. The frontend (live at arcinherit.com) adds a client-side heir PDF generator, a claim-share calculator, a custom-error decoder, RPC fallback, and a guided side-by-side migration between two immutable contract versions.