Vault: creditAvailable and debtOutstanding

What You Are Building

Two view functions that drive the vault's dynamic capital allocation. creditAvailable(strategy) answers "how much new underlying can this strategy draw on its next harvest?" debtOutstanding(strategy) answers "how much of this strategy's current debt should be returned on its next harvest?"

These are pure-view functions called by the strategy's harvest() (section 15). The strategy reads them, decides how much to send back and how much new capital to deploy, then calls vault.report() (section 11) to settle.