fix: improve frontend UX and fix OKX close position

Frontend improvements:
- Replace window.location.reload() with SWR mutate() for data refresh
- Replace native alert/confirm with toast notifications (confirmToast, notify)
- Add loading skeletons to AITradersPage and EquityChart
- Fix flash of empty state during initial load
OKX fixes:
- Fix proxy issue in Docker by using explicit no-proxy function
- Fix CloseShort sz parameter error - ensure quantity is always positive
- Fix GetPositions to return absolute value for positionAmt

web/src/components/EquityChart.tsx

@@ -41,7 +41,7 @@ export function EquityChart({ traderId, embedded = false }: EquityChartProps) {
   const { user, token } = useAuth()
   const [displayMode, setDisplayMode] = useState<'dollar' | 'percent'>('dollar')
 
-  const { data: history, error } = useSWR<EquityPoint[]>(
+  const { data: history, error, isLoading } = useSWR<EquityPoint[]>(
     user && token && traderId ? `equity-history-${traderId}` : null,
     () => api.getEquityHistory(traderId),
     {
@@ -61,6 +61,22 @@ export function EquityChart({ traderId, embedded = false }: EquityChartProps) {
     }
   )
 
+  // Loading state - show skeleton
+  if (isLoading) {
+    return (
+      <div className={embedded ? 'p-6' : 'binance-card p-6'}>
+        {!embedded && (
+          <h3 className="text-lg font-semibold mb-6" style={{ color: '#EAECEF' }}>
+            {t('accountEquityCurve', language)}
+          </h3>
+        )}
+        <div className="animate-pulse">
+          <div className="skeleton h-64 w-full rounded"></div>
+        </div>
+      </div>
+    )
+  }
+
   if (error) {
     return (
       <div className={embedded ? 'p-6' : 'binance-card p-6'}>