fix: Improve payment gateway display and modal z-index

✅ Payments Page Fixes:
- Use method_title instead of title for unique gateway names
  - Manual: Shows 'Direct bank transfer' instead of empty
  - 3rd Party: Shows 'TriPay - BNI VA' instead of 'Pembayaran TriPay'
- Use method_description for 3rd party gateways
- Rename 'Other Payment Methods' → '3rd Party Payment Methods'
- Better description: 'Additional payment gateways from plugins'

✅ Modal Z-Index Fix:
- Increased dialog overlay z-index: z-50 → z-[9999]
- Increased dialog content z-index: z-50 → z-[9999]
- Ensures modals appear above fullscreen mode elements

🎯 Result:
- No more duplicate 'Pembayaran TriPay' × 5
- Each gateway shows unique name from WooCommerce
- Modals work properly in fullscreen mode

Addresses user feedback from screenshots 1-4

admin-spa/src/routes/Settings/Payments.tsx

@@ -166,7 +166,7 @@ export default function PaymentsPage() {
                         <Banknote className="h-5 w-5 text-muted-foreground" />
                       </div>
                       <div>
-                        <h3 className="font-medium">{gateway.title}</h3>
+                        <h3 className="font-medium">{gateway.method_title || gateway.title}</h3>
                         {gateway.description && (
                           <p className="text-sm text-muted-foreground mt-1">
                             {gateway.description}
@@ -230,7 +230,7 @@ export default function PaymentsPage() {
                       </div>
                       <div className="flex-1">
                         <div className="flex items-center gap-2 mb-1">
-                          <h3 className="font-semibold">{gateway.title}</h3>
+                          <h3 className="font-semibold">{gateway.method_title || gateway.title}</h3>
                           {gateway.enabled ? (
                             <Badge variant="default" className="bg-green-500">
                               ● Enabled
@@ -276,11 +276,11 @@ export default function PaymentsPage() {
           )}
         </SettingsCard>
 
-        {/* Other Gateways */}
+        {/* 3rd Party Gateways */}
         {otherGateways.length > 0 && (
           <SettingsCard
-            title="Other Payment Methods"
-            description="Additional payment gateways"
+            title="3rd Party Payment Methods"
+            description="Additional payment gateways from plugins"
           >
             <div className="space-y-4">
               {otherGateways.map((gateway: PaymentGateway) => (
@@ -294,10 +294,10 @@ export default function PaymentsPage() {
                         <CreditCard className="h-5 w-5 text-muted-foreground" />
                       </div>
                       <div>
-                        <h3 className="font-medium">{gateway.title}</h3>
-                        {gateway.description && (
+                        <h3 className="font-medium">{gateway.method_title || gateway.title}</h3>
+                        {gateway.method_description && (
                           <p className="text-sm text-muted-foreground mt-1">
-                            {gateway.description}
+                            {gateway.method_description}
                           </p>
                         )}
                       </div>