feat(payments): complete Story 1.1 - Add loading overlay and error messages to all payment panels

- Updated GoPayPanel with LoadingOverlay and mapErrorToUserMessage
- Updated CStorePanel with LoadingOverlay and mapErrorToUserMessage
- All 3 payment methods now show user-friendly Bahasa Indonesia error messages
- Full-screen loading overlay prevents duplicate payment code generation

Story: 1.1 - Prevent Duplicate VA/QR/Code Generation & Improve Feedback
Status: Complete

src/features/payments/components/CStorePanel.tsx

@@ -5,6 +5,8 @@ import React from 'react'
 import { PaymentInstructions } from './PaymentInstructions'
 import { postCharge } from '../../../services/api'
 import { InlinePaymentStatus } from './InlinePaymentStatus'
+import { LoadingOverlay } from '../../../components/LoadingOverlay'
+import { mapErrorToUserMessage } from '../../../lib/errorMessages'
 
 type StoreKey = 'alfamart' | 'indomaret'
 
@@ -36,7 +38,7 @@ export function CStorePanel({ orderId, amount, locked, onChargeInitiated, defaul
             if (typeof res?.store === 'string') setStoreFromRes(res.store)
           }
         } catch (e) {
-          if (!cancelled) toast.error(`Gagal membuat kode pembayaran: ${(e as Error).message}`)
+          if (!cancelled) toast.error(mapErrorToUserMessage(e))
         } finally {
           if (!cancelled) setBusy(false)
           cstoreTasks.delete(chargeKey)
@@ -60,7 +62,7 @@ export function CStorePanel({ orderId, amount, locked, onChargeInitiated, defaul
           if (typeof res?.store === 'string') setStoreFromRes(res.store)
         }
       } catch (e) {
-        if (!cancelled) toast.error(`Gagal membuat kode pembayaran: ${(e as Error).message}`)
+        if (!cancelled) toast.error(mapErrorToUserMessage(e))
         attemptedCStoreKeys.delete(chargeKey)
       } finally {
         if (!cancelled) setBusy(false)
@@ -78,6 +80,8 @@ export function CStorePanel({ orderId, amount, locked, onChargeInitiated, defaul
   }
 
   return (
+    <>
+      <LoadingOverlay isLoading={busy} message="Sedang membuat kode pembayaran..." />
       <div className="space-y-3">
         <div className="font-medium">Convenience Store</div>
         {selected && (
@@ -126,5 +130,6 @@ export function CStorePanel({ orderId, amount, locked, onChargeInitiated, defaul
           <InlinePaymentStatus orderId={orderId} method="cstore" />
         </div>
       </div>
+    </>
   )
 }

src/features/payments/components/GoPayPanel.tsx

@@ -6,6 +6,8 @@ import { GoPayLogosRow } from './PaymentLogos'
 import { postCharge } from '../../../services/api'
 import { InlinePaymentStatus } from './InlinePaymentStatus'
 import { toast } from '../../../components/ui/toast'
+import { LoadingOverlay } from '../../../components/LoadingOverlay'
+import { mapErrorToUserMessage } from '../../../lib/errorMessages'
 
 // Global guards/tasks to stabilize QR generation across StrictMode remounts
 const attemptedChargeKeys = new Set<string>()
@@ -52,7 +54,9 @@ export function GoPayPanel({ orderId, amount, locked, onChargeInitiated }: { ord
     }
   }
   return (
+    <>
       <div className="space-y-3">
+        <LoadingOverlay isLoading={busy} message="Sedang membuat kode QR..." />
         <GoPayPanel_AutoEffect
           orderId={orderId}
           amount={amount}
@@ -147,6 +151,7 @@ export function GoPayPanel({ orderId, amount, locked, onChargeInitiated }: { ord
           </div>
         </div>
       </div>
+    </>
   )
 }
 
@@ -175,7 +180,7 @@ export function GoPayPanel_AutoEffect({ orderId, amount, locked, mode, setBusy,
             onChargeInitiated?.()
           }
         } catch (e) {
-          if (!cancelled) toast.error(`Gagal membuat QR: ${(e as Error).message}`)
+          if (!cancelled) toast.error(mapErrorToUserMessage(e))
         } finally {
           if (!cancelled) {
             setBusy(false)
@@ -204,7 +209,7 @@ export function GoPayPanel_AutoEffect({ orderId, amount, locked, mode, setBusy,
           onChargeInitiated?.()
         }
       } catch (e) {
-        if (!cancelled) toast.error(`Gagal membuat QR: ${(e as Error).message}`)
+        if (!cancelled) toast.error(mapErrorToUserMessage(e))
         attemptedChargeKeys.delete(chargeKey)
       } finally {
         if (!cancelled) {