fix(client/payment): switchMethod 补 catch-all 兜网络/超时错(与 start/resume 对齐)防卡 awaitingPayment

switchMethod 的首个 retry() 调用只 catch AuthApiException,网络/超时/未知异常会穿出到
无 try/catch 的 _pickAndSwitch,UI 卡在 awaitingPayment 无任何提示。补一个 catch-all,
与 start()/resume() 同一处理形状落 failed 相位(自动经 build() 切到 _failed() 呈现);
payment_page.dart 的 _pickAndSwitch 再加一层防御性 try/catch + toast,防任何逃逸异常
变成无提示的 unhandled rejection。补单测覆盖非 Auth 异常路径。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P9G7E3wmAYL9KeYCVZVsqu

client/lib/screens/payment_page.dart

@@ -245,9 +245,16 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
     ]);
   }
 
+  // switchMethod 内部已把网络/超时/未知异常兜到 failed 相位(与 start/resume 对齐,
+  // 会经 build() 的 phase 分支自动切到 _failed() 呈现)——这里的 try/catch 是最后一道
+  // 防线,防止任何逃逸异常变成无提示的 unhandled rejection(照抄 _openRedirectUrl 的写法)。
   Future<void> _pickAndSwitch(BuildContext context, WidgetRef ref, PaymentFlowState s) async {
     final other = s.method == 'crypto' ? 'nezha' : 'crypto';
-    await ref.read(paymentFlowProvider.notifier).switchMethod(other);
+    try {
+      await ref.read(paymentFlowProvider.notifier).switchMethod(other);
+    } catch (_) {
+      if (context.mounted) showPangolinToast(context, t.orderCreateFailed);
+    }
   }
 
   Widget _succeeded(BuildContext context, PaymentFlowState s) {

client/lib/state/payment_provider.dart

@@ -169,6 +169,15 @@ class PaymentFlowController extends StateNotifier<PaymentFlowState> {
         return;
       }
       state = state.copyWith(phase: PaymentPhase.failed, errorZh: e.messageZh, errorEn: e.messageEn);
+    } catch (_) {
+      // 网络/超时等非 Auth 异常也要落 failed —— 与 start()/resume() 同一形状,否则
+      // 穿出到无 try/catch 的 _pickAndSwitch,UI 卡在 awaitingPayment 无提示。
+      if (!mounted) return;
+      state = state.copyWith(
+        phase: PaymentPhase.failed,
+        errorZh: '下单失败，请检查网络后重试',
+        errorEn: 'Failed to create order, please check your network and retry',
+      );
     }
   }
 

client/test/unit/payment_flow_test.dart

@@ -105,6 +105,20 @@ void main() {
     expect(c.read(paymentFlowProvider).order?.orderNo, 'pay2');
   });
 
+  test('switchMethod 遇非 Auth 异常(网络/超时)→ 落 failed 兜底,不卡 awaitingPayment', () async {
+    final api = _FakePaymentApi();
+    final c = _container(api);
+    final ctl = c.read(paymentFlowProvider.notifier);
+    await ctl.start(item, 'crypto');
+    api.retryError = Exception('network timeout');
+    await ctl.switchMethod('alipay');
+    expect(c.read(paymentFlowProvider).phase, PaymentPhase.failed);
+    expect(c.read(paymentFlowProvider).errorZh, isNotNull);
+    expect(c.read(paymentFlowProvider).errorZh, isNotEmpty);
+    expect(c.read(paymentFlowProvider).errorEn, isNotNull);
+    expect(c.read(paymentFlowProvider).errorEn, isNotEmpty);
+  });
+
   test('resume() 成功 → retry 恢复原单会话(不新下单),phase=awaitingPayment', () async {
     final api = _FakePaymentApi();
     final c = _container(api);