Add AGT treasury withdrawal vote script

[cinnabarhorse]

Summary

• add a reusable helper that builds the nested Aragon CallsScripts needed to create an AGT treasury withdrawal vote
• add a callable script that prints the payload by default and can broadcast TokenManager.forward(...) when --broadcast is provided
• add a mainnet-fork Hardhat test that verifies an AGT holder can create the real treasury vote path on Ethereum

Test

• ./scripts/fast-check.sh test/agtTreasuryWithdrawalVoteScript.test.ts

Deployment evidence

• N/A (script and test only)