Add Net USD Value display to dashboard

- Updated AccountBalance interface to include netUsdValue and unrealizedPnl
- Enhanced getAccountBalance() to calculate Net USD Value (collateral + unrealized PnL)
- Added Net USD Value calculation from all position unrealized PnL
- Updated Dashboard.tsx to display Net USD Value as primary metric
- Added new stats card with emerald styling for Net USD Value
- Reorganized stats grid to 6 columns to accommodate new metric
- Net USD Value = Total Collateral + Total Unrealized PnL from all positions

components/Dashboard.tsx

@@ -17,7 +17,8 @@ export default function Dashboard() {
     dailyPnL: 0,
     winRate: 0,
     totalTrades: 0,
-    accountValue: 0
+    accountValue: 0,
+    netUsdValue: 0
   })
 
   useEffect(() => {
@@ -48,7 +49,8 @@ export default function Dashboard() {
                 const balanceData = await balanceRes.json()
                 setStats(prev => ({
                   ...prev,
-                  accountValue: balanceData.accountValue || 0
+                  accountValue: balanceData.accountValue || 0,
+                  netUsdValue: balanceData.netUsdValue || 0
                 }))
               }
             } catch (e) {
@@ -62,7 +64,8 @@ export default function Dashboard() {
               dailyPnL: 0,
               winRate: 0,
               totalTrades: 0,
-              accountValue: 0
+              accountValue: 0,
+              netUsdValue: 0
             })
           }
         } else {
@@ -74,7 +77,8 @@ export default function Dashboard() {
             dailyPnL: 0,
             winRate: 0,
             totalTrades: 0,
-            accountValue: 0
+            accountValue: 0,
+            netUsdValue: 0
           })
         }
       } catch (e) {
@@ -86,7 +90,8 @@ export default function Dashboard() {
           dailyPnL: 0,
           winRate: 0,
           totalTrades: 0,
-          accountValue: 0
+          accountValue: 0,
+          netUsdValue: 0
         })
       }
       setLoading(false)
@@ -97,7 +102,21 @@ export default function Dashboard() {
   return (
     <div className="space-y-8">
       {/* Stats Cards */}
-      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-5 gap-6">
+      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-6 gap-6">
+        <div className="card card-gradient">
+          <div className="flex items-center justify-between">
+            <div>
+              <p className="text-gray-400 text-sm font-medium">Net USD Value</p>
+              <p className="text-2xl font-bold text-emerald-400">
+                ${stats.netUsdValue.toFixed(2)}
+              </p>
+            </div>
+            <div className="w-12 h-12 bg-emerald-500/20 rounded-full flex items-center justify-center">
+              <span className="text-emerald-400 text-xl">💎</span>
+            </div>
+          </div>
+        </div>
+
         <div className="card card-gradient">
           <div className="flex items-center justify-between">
             <div>