Fixes from Stephen's review

web/components/amount-input.tsx

@@ -250,7 +250,7 @@ export function SellAmountInput(props: {
             Sale proceeds{' '}
             <span className="text-neutral">{formatMoney(saleValue)}</span>
           </Row>
-          {prevLoanAmount && (
+          {!!prevLoanAmount && (
             <Row className="items-center justify-between gap-2 text-gray-500">
               <Row className="items-center gap-2">
                 Loan repaid{' '}

web/components/bet-panel.tsx

@@ -364,7 +364,7 @@ function SellPanel(props: {
 
   const initialProb = getProbability(contract)
   const { newPool } = calculateCpmmSale(contract, {
-    shares: amount ?? 0,
+    shares: Math.min(amount ?? 0, shares),
     outcome: sharesOutcome,
   })
   const resultProb = getCpmmProbability(newPool, contract.p)