vestoken/v0 package

Package vestoken is a fungible token where new supply is never handed out instantly — it ports the idea behind Solidity's VestingWallet / linear token-streaming contracts (e.g. Sablier) into a single gno.land realm.

MintVested opens a linear vesting grant instead of crediting a balance directly. The beneficiary calls Claim over time to pull whatever has unlocked so far into their liquid, transferable balance. State is package-level and persistent; state-mutating functions are crossing functions (`cur realm`) per the gno 0.9 interrealm convention.