USDC distributed per share (lazy index)
HPT circulating as Coin<T>
Share of supply held as Coin<T>
Wrapped tokens earn no yield while wrapped — the index denominator is unwrapped supply only, so unwrapped holders earn the wrapped holders' share.
The TreasuryCap<HPT> is custodied inside the accumulator forever — only the wrap machine can mint/burn, so supply always equals wrapped shares.