The absolute ceiling: the largest draw the contract accepts right now, with NO margin.
In normal mode, with the individual ratio binding, it opens the position at exactly the 110%
minimum collateral ratio. Liquidation is ICR < MCR (TroveManager.sol:1146-1148) and the debt
accrues every second (TroveManager.sol:1513-1527), so a Trove opened here is liquidatable
within a second (MK-100, measured in zz-borrowing-power-boundary.fork.test.ts). In Recovery
Mode it opens at exactly 150%. With the system ratio binding, the open is refused a block later.
Do not open at it. It is a limit to display, not an amount to borrow, and it holds for the
block it was read at.
The ICR a Trove opened at ceiling starts at, at price. 0n when ceiling is 0n.
The largest draw that still clears every open gate after margin.priceFallBps of price fall and
margin.horizonSeconds of interest. A Trove opened at it starts at an ICR of at least the
threshold times price / margin.stressedPrice, and it is not liquidatable while the price divided
by one plus the interest accrued since the open stays at or above margin.stressedPrice. 0n when
no open with that margin clears the debt floor.
It is an answer to the margin in margin and to nothing else. A fall larger than it, a hold longer
than it, or debt redistributed to the Trove from another Trove's liquidation
(TroveManager.sol:980-1047) can still take the position to liquidation.
The ICR a Trove opened at draw starts at, at price. 0n when draw is 0n.
checkRecoveryMode(price), which picks the individual ratio threshold.
The margin draw was solved with.
BTC/USD the ceiling was solved at.
Result of MusdClient.drawForMargin: a draw that answers the caller's margin, beside the ceiling.